MDCAT 1ST DIAGNOSTIC TEST & 2ND DIAGNOSTIC TEST with Answers and Explanations

 

1ST DIAGNOSTIC TEST

 

Directions:      Each set if lettered choices below refers to the numbered statements immediately following it. Select the one lettered choice that best answers each question or best fits each statement, and then fill I the corresponding oval on the answer sheet. A choice may be used once, more than one, or not at all in each set.

 

Question 1-3

(A)       Mitochondria

(B)        Cytoplasm

(C)        Pyruvate

(D)       Lactic acid

(E)        Glucose

 

1.           Location of cellular respiration in prokaryotes

 

2.           End product of anaerobic metabolism in muscle cells

 

3.           Location of glycolysis in eukaryotes

 

Question 4-6

(A)       Anaphase II

(B)        Metaphase I

(C)        Prophase II

(D)       Metaphase II

(E)        Prophase I

 

4.           Stage of meiosis during which recommendation of genetic material occurs

 

5.           Stage of meiosis during which pairs of homologous chromosomes align at the center of the cell

 

6.           Stage of meiosis during which sister chromatids are separated.

 

Question 7-9

(A)       Reasoning/insight

(B)        Imprinting

(C)        Classical conditioning

(D)       Habituation

(E)        Instinct

 

7.           A simple kind of learning involving loss of sensitivity to unimportant stimuli.

 

8.           Greese recognize a ticking clock as “mother” if exposed to it during a critical period shortly after hatching.

 

9.           Fish are given food at the same time as a tap on their glass bowl and soon learn to approach when a tap sounds even in the absence of food.

 

Question 10-12

(A)       Small intestine

(B)        Large intestine

(C)        Stomach

(D)       Esophagus

(E)        Mouth

 

10.       Structure where most digestion and absorption of nutrient occurs

 

11.       Structure where starch digestion first takes place

 

12.       Structure with the lowest pH.

 

Directions:      Each of the questions or incomplete statements below is followed by five suggested answers or completions. Some questions pertain to a set that refers to a laboratory or experimental situation. For each question, select the one choice that is the best answer to the question and then fill in the corresponding oval on the answer sheet.

 

13.       Homologous structures, which have similar underlying structure but may have different functions, are formed by

 

(A)       Divergent evolution

(B)        speciation

(C)        segregation

(D)       convergent evolution

(E)        stabilizing selection

 

14.       Hemoglobin is a protein in red blood cells that binds and carries oxygen and some carbon dioxide. Its affinity for oxygen changes as blood travels from the lungs to the body tissues and back to the lungs again. One could expect hemoglobin to have.

 

(A)       A high carbon dioxide affinity in the lungs and a low oxygen affinity in the tissues

(B)        A low carbon dioxide affinity in the lungs and a high oxygen affinity in the tissues

(C)        A high oxygen affinity in the lungs and a low oxygen affinity in the tissues

(D)       A low oxygen affinity in the lungs and a high oxygen affinity in the tissues

(E)        A high oxygen affinity in the lungs and a high carbon dioxide affinity in the tissues

 

15.       Which of the following RNA sequences would be transcribed from the DNA sequence ATGCCTAGGAC?

 

(A)       TACGGATCCTG

(B)        UAGCGAUCCUG

(C)        AUGCCUAGGAC

(D)       UACGGAUCCUG

(E)        GCAUUCGAAGU

 

16.       Arthropods can be characterized by all of the following EXCEPT.

 

(A)       A hard exoskeleton

(B)        A water vascular system

(C)        Jointed appendages

(D)       Molting

(E)        Segmented body

 

17.       Which of the following are functions of the kidney?

 

I.       Filtration of blood to remove wastes

II.    Blood pressure regulation

III. pH regulation

 

(A)       I only

(B)        I and II only

(C)        I and III only

(D)       II and III only

(E)        I, II and III

 

18.       In chickens, the allele for long tail feathers (T) is dominant over the allele for short tail feathers (t). If a pure-breeding long-tailed chicken (TT) mates with a pure-breeding short-tailed chicken (tt), what percentage of their offspring (if mated with the correct genotype) could give rise to chickens with short tails?

 

(A)       25%

(B)        50%

(C)        75%

(D)       100%

(E)        Unable to determine from the information given

 

19.       All of the following could be considered density dependent factors affecting population growth EXCEPT.

 

(A)       Limited nutrients

(B)        Climate temperature

(C)        Build-up of toxins

(D)       predation

(E)        limited water

 

20.       The best definition of a species is

 

(A)       A group of organisms that occupy the same niche

(B)        A population that works together

(C)        A group of organisms that can mate with each other

(D)       A population that preys on other populations

(E)        A population in which all members benefit from the association in some way

 

21.       Which of the following contains blood poor in oxygen?

 

I.       Right ventricle

II.    Pulmonary vein

III. Pulmonary vein

 

(A)       I only

(B)        II only

(C)        III only

(D)       I and III only

 

22.       An organism appears to be segmented worm. Upon observation it is determined that the organism has a closed circulation, a mouth and an anus, and does NOT have an exoskeleton. The organism most likely belongs to the pylulm.

 

(A)       mollusca

(B)        annelida

(C)        echinodermata

(D)       arthropoda

(E)        chordata

 

23.       Which of the following sustances are produced by the light reactions of photosynthesis?

 

(A)       ATP and NADPH

(B)        ATP and glucose

(C)        NADPH and glucose

(D)       ATP and NADH

(E)        NADPH and glucose

 

24.       Consider the following graph of substrate concentration vs product formation. Assume enzyme concentration to be constant. Why does the graph level off at high substrate concentrations?

 

 

 

 

 

 

Diagram

(A)       All the enzyme is used up, and product formation cannot occur without is.

(B)        There is no more substrate to be converted into product.

(C)        Substrate concentration, exceeds enzyme concentration, and all active sites are saturated.

(D)       The reaction has run to completion.

(E)        An inhibitor has been added, and it has slowed down the rate of product formation.

 

25.       A bird that feeds on both insects and berries would be classified as a

 

I.       Primary consumer

II.    Secondary consumer

III. Tertiary consumer

 

(A)       I only

(B)        II only

(C)        III only

(D)       I & II only

(E)        II & III only

 

26.       Which of the following chemical formulas could represent a carbohydrate?

 

(A)       C6H6O6

(B)        C3H6O3

(C)        C6H12O3

(D)       C5H10O10

(E)        CH2O4

 

27.       A population of birds lives in an area with many insects upon which it feeds. The insects live inside trees, burrowing into the bark. Over many hundreds of years, the average beak size in the bird population has increased. This is due to

 

(A)       increased fitness of the birds, leading to speciation

(B)        decreased fitness of the insects, allowing the birds to catch them more easily

(C)        increased fitness of large-beaked birds, leading to evolution

(D)       decreased fitness of small-beaked birds, leading to speciation

(E)        random mutation and genetic recombination

 

28.       The location on an enzyme where a substrate binds is called

 

(A)       binding site

(B)        reaction center

(C)        allosteric site

(D)       lock-and-key model

(E)        active site

 

29.       Human cells maintain concentration gradients across their plasma membranes, such that there is a high sodium concentration outside the cell and a high potassium concentration inside the cell. Suppose that within the cell membrane are sodium “leak” channels. These channels would allow sodium to

 

(A)       move out of the cell by simple diffusion

(B)        move into the cell by simple diffusion

(C)        move out of the cell by facilitated diffusion

(D)       move into the cell by facilitated diffusion

(E)        move into the cell by active transport

 

30.       The role of decomposers in the nitrogen cycle is to

 

(A)       fix atmospheric nitrogen into ammonia

(B)        incorporate nitrogen into amino acids and organic compounds

(C)        convert ammonia to nitrate, which can then be absorbed by plants

(D)       denitrify ammonia, thus returning nitrogen to the atmosphere

(E)        release ammonia from organic compounds, thus returning it to the soil

 

31.       All of the following are true about the endocrine system EXCEPT.

 

(A)       it relies on chemical messengers that travel through the bloodstream

(B)        it is a control system that has extremely rapid effects on the body

(C)        the hormones affect only certain “target” organs

(D)       it is involved in maintaining body homeostasis

(E)        its organs secrete hormones directly into the bloodstream, rather than through ducts

 

32.       Two organisms live i close association with each other. One organism is helped by the association, whereas the other is neither helped nor harmed. Which of the following terms best describes this relationship?

(A)       Mutualism

(B)        Commensalism

(C)        Symbiosis

(D)       Parasitism

(E)        Predator-prey-relationship

 

33.       Cardiac output (the amount of blood pumped out of the heart in one minute) and blood pressure are directly proportiona. Which of the following graphs best depicts the relationship between cardiac output and blood pressure?

 

 

 

 

 

Diagrams

 

Question 34-36 refer to the following diagram.

 

 

Diagram

 

34.       Location where male haploid cells are produced

(A)       1

(B)        2

(C)        3

(D)       6

(E)        8

 

35.       Sticky structure where pollen grains can attach and germinate

(A)       1

(B)        2

(C)        3

(D)       6

(E)        8

 

36.       Structure which, when fertilized, develops into fruit

(A)       1

(B)        2

(C)        3

(D)       6

(E)        8

 

 

Question 37-38

Tropisms refer to movements made by plants toward or away from certain stimuli. “Positive” tropisms refer specifically to movements toward a stimulus, whereas “negative” tropisms refer to movements made away from a stimulus.

 

37.       A plant growing on the shady side of a building bends around the corner of the building toward the sunlight. This is an example of

(A)       negative geotropism

(B)        negative phototropism

(C)        positive phototropism

(D)       positive hydrotropism

(E)        negative hydrotropism

 

38.       The stem and leaves of the plant grow up, away from the soil. This is an example of

(A)       negative geotropism

(B)        positive geotropism

(C)        negative phototropism

(D)       positive hydrotropism

(E)        negative hydrotropism

 

Question 39-43 refer to the following diagram.

 

 

 

 

Diagram

39.       The hormone labeled X in the diagram is often used in over the counter diagnostic tests to determine when ovulation has occurred. This hormone is

(A)       estrogen

(B)        progesterone

(C)        FSH

(D)       LH

(E)        Testosterone

 

40.       Based on the peak levels of hormone X, on what day of the cycle is ovulation most likely to occur?

(A)       Day 21

(B)        Day 14

(C)        Day 12

(D)       Day 25

(E)        Day 28

 

41.       The hormone labeled Y in the diagram is

(A)       progesterone, secreted by the corpus luteum after ovulation has occurred

(B)        progesterone, secreted by the ovary after ovulation has occurred
estrogen, secreted by the corpus luteum after ovulation has occurred

(C)        estrogen, secreted by the ovary after ovulation has occurred

(D)       estrogen, secreted by the follicle before ovulation occurs

 

 

42.       Immediately after fertilization, the zygote begins to undergo rapid cell division. This process is

(A)       Blastulation

(B)        Gastrulation

(C)        Neurulation

(D)       Implantation

(E)        cleavage

 

43.       From which of the primary germ layers does the nervous system develop?

(A)       Endoderm

(B)        Mesoderm

(C)        Ectoderm

(D)       Enteroderm

(E)        Epidermis

 

Question 44-46

A barren, rocky community near a lake has virtually no vegetation or animal life. After a period of approximately 75 years, the community boasts a wide variety of flora and fauna, including deciduous trees, deer, and raccoon.

 

44.       The process which has taken place can best be described as

(A)       Progression

(B)        Succession

(C)        Evolution

(D)       Habitation

(E)        colonization

 

45.       The stable community of deciduous trees and animals in known as the

(A)       Colonization

(B)        final community

(C)        climax community

(D)       apex community

(E)        summit community

(F)         composite community

 

46.       Usually the first organisms to colonize rocky areas are lichen. These are known as the

(A)       primary community

(B)        starter community

(C)        colony organisms

(D)       pioneer organisms

(E)        settler organisms

 

Question 47-50

Diuretics are substances that help eliminate water from the body. The effects of various substances were tested on several volunteers. All volunteers had a mass of 70 kg. They drank nothing for eight hours before the test and urinated just prior to ingesting the test substance. The three substances (water, caffeine, and salt) were tested on three separate days. The results are shown in the tables below.

 

 

Table 1

Volunteer

amount caffeine ingested

(in 100 ml water)

volume urine

collected after 1 hour

                   A          

50 mg

302 ML

                   B          

100 mg

492 ml

                   C          

150 mg

667 ml

                   D          

200 mg

863 ml

 

Table 2

Volunteer

amount sodium chloride ingested

(in 100 ml water)

volume urine

collected after 1 hour

                   A          

9 g

201 ML

                   B          

1.8 g

162 ml

                   C          

2.7 g

125 ml

                   D          

3.6 g

82 ml

 

Table 3

Volunteer

Volume water ingested

volume urine

collected after 1 hour

                   A          

100 ml

230 ML

                   B          

200 ml

240 ml

                   C          

300 ml

252 ml

                   D          

400 ml

263 ml

 

47.       Which of the following substances could be classified as a diuretic?

 

I.       Caffeine

II.    Sodium

III. Water

 

(A)       I only

(B)        II only

(C)        I and II only

(D)       II and III only

(E)        I, II and III

 

48.       Which graph best represents the change in urine volume when ingesting caffeine?

 

 

 

Diagrams

 

49.       The purpose of ingesting the plain water (Table 3) was to

(A)       rehydrate the volunteers

(B)        dissolve the substances

(C)        act as a control

(D)       flush out the kidneys

(E)        act as a positive test substance

50.       Based on the results in table 2, if a volunteer were to ingest 4.5 g sodium chloride dissolved in 100 ml water, what would be the approximate predicted urine volume collected after one hour?

(A)       20 ml

(B)        30 ml

(C)        40 ml

(D)       50 ml

(E)        60 ml

 

Question 51-53 refer to the following information on heredity.

Hemophilia is a disorder in which blood fails to clot. John, a male hemophiliac, marries Jane, a normal woman, and together they have four children, two boys (Mark and Mike) and two girls (Molly and Mary). None of the children display the symptoms of hemophilia, Mark, Mike, Molly and Mary all marry normal individuals and have children. None of Mark's or Mike's children, male or female, display symptoms of hemophilia, but the sons of Molly and Mary all display symptoms of hemophilia while the daughters of Molly and Mary do not.

 

51.       Which of the following best explains the reason that Mark, Mike, Molly and Mary do not display symptoms of hemophilia, even though their father, John, is a hemophiliac?

(A)       Hemophilia is an X-linked disorder, and John can pass on only his Y chromosome.

(B)        Hemophilia is an X-linked disorder, and even though Molly and Mary received a hemophiliac X chromosome from John, Jane gave them a normal X chromosome.

(C)        Hemophilia is a Y-linked disorder and therefore cannot be displayed in females.

(D)       Hemophilia is a Y-linked disorder and Mark and Mike must have received an X chromosome from John.

(E)        Hemophilia is an X-linked disorder, and even though Mark and Mike received a hemophiliac X chromosome from John, Jane gave them a normal X chromosome.

 

52.       If one of Mike's daughters marries a normal man, what is the probability that one of their children will display symptoms of hemophilia?

(A)       0%

(B)        25%

(C)        50%

(D)       75%

(E)        100%

 

53.       Which of the following individuals are heterozygous for hemophilia?

(A)       John, Mark and Mike

(B)        Mark, Mike, Molly and Mary

(C)        John and Jane

(D)       Molly and Mary

(E)        Mark and Mike

 

Question 54-57

A volunteer was injected intravenously with several test substances to determine the effect of each substance on normal body variables. The results are shown in Table 1. Assume that enough time was allowed between injections so that the substances do not interfere with one another

 

 

Table 1

Variable

baseline values

values after injecting substance A

values after injecting substance B

values after injecting substance C

values after injecting substance D

Serum Ca++

2.3 mmol/L

2.3 mmol/L

3.0 mmol/L

2.3 mmol/L

2.3 mmol/L

Serum Na+

135 mmol/L

135 mmol/L

136 mmol/L

135 mmol/L

147 mmol/L

Serum glucose

5.6 mmol/L

3.3 mmol/L

3.6 mmol/L

7.4 mmol/L

5.6 mmol/L

 

54.       Based on the information in Table 1, which of the following is most likely substance B?

(A)       Calcitonin

(B)        Insulin

(C)        Parathyroid hormone

(D)       Glucagon

(E)        Aldosterone

 

55.       Based on the information in Table 1, which of the following is most likely substance A?

(A)       Glucagon

(B)        Aldosterone

(C)        Calcitonin

(D)       Parathyroid hormone

(E)        Insulin

 

56.       Under what conditions might substance D be released normally?

(A)       soon after a meal

(B)        When blood pressure is low

(C)        Between meals

(D)       When there has been limited intake of dietary calcium

(E)        when dietary calcium is in excess

 

57.       All of the following changes in variable values are significant EXCEPT

(A)       the change in serum glucose when substance A is injected

(B)        the change in serum Na+ when substance D is injected

(C)        the change in serum Ca++ when substance B is injected

(D)       the change in serum glucose when substance C is injected

(E)        the change in serum Na+ when substance B is injected

 

Question 58-60

Three different cell types were observed under the microscope. The observations are summarized in Table 1.

 

Table 1

Cell type

Nucleus?

Cell wall?

Chloroplasts?

                               A          

No

Yes

No

                                B          

Yes

Yes

No

                                C          

Yes

Yes

Yes

 

The three cell types were grown in separate cultures with plenty of oxygen and nutrients available. Figure 1 shows their rates of growth. At Time 1, oxygen was no longer available to the cells.

 

 

 

Figure 1

 

58.       Based on the information in Table 1, which of the following is the most likely classification of cell Type A?

 

(A)       Fungi

(B)        Plant

(C)        Bacteria

(D)       Animal

(E)        protist

 

59.       Which of the following equation is cell Type C able to run?

I.       C6H12O6 + 6O2  6CO2 + 6H2O + ATP

II.    H2O + light  O2 + ATP + NADPH

III. 6CO3 + 6H2O + ATP + NADPH  C6H12O6

 

(A)       I only

(B)        II only

(C)        I and II only

(D)       II and III only

(E)        I, II and III

 

60.       Consider Figure 1. Which of the following statements best describes the reason for the difference between the curves for cell Type B and cell Type C?

 

(A)       Cell type B is unable to survive in the presence of oxygen, while cell Type C can ferment.

(B)        The products of fermentation in cell Type C are toxic to the cells and they are dying.

(C)        Cell Type B is an obligate aerobe while cell Type C is able to ferment.

(D)       Cell Type B is a facultative anaerobe, while cell Type C is an obligate aerobe.

(E)        Cell Type C is an obligate aerobe, while cell Type B is an obligate aerobe.

 

Directions:      Each of the questions or incomplete statements below is followed by five suggested answers or completions. Some questions pertain to a set that refers to a laboratory or experimental situation. For each question, select the one choice that is the best answer to the question and then fill in the corresponding oval on the answer sheet.

 

Question 61-64

 

61.       The driest of all terrestrial biomes, characterized by low and unpredictable precipitation

 

(A)       Thundra

(B)        Taiga

(C)        Tropical rain forest

(D)       Deciduous forest

(E)        Desert

 

62.       Coniferous forests, characterized by long, cold winters and short, wet summers

 

63.       Biome characterized by great diversity of flora and fauna and high levels of precipitation

 

64.       Northern areas, characterized by permafrost, extremely cold temperatures and few trees

 

65.       Plants that have true roots, stems and leaves, as well as flowers and seeds enclosed in fruit, are classified as

(A)       bryophytes

(B)        tracheophytes

(C)        gymnosperms

(D)       angiosperms

(E)        endosperms

 

66.       Which of the following indicates that animals have internal biological clocks?

(A)       A mouse kept in constant darkness shows a daily rhythm of activity.

(B)        A rooster crows whenever the sun rises in both winter and summer.

(C)        An owl kept in constant light drifts away from a 24-hour cycle.

(D)       Some species ……

(E)        A squirrel whose night and day are artificially reversed soon adapts to its schedule.

 

67.       Which of the following correctly lists the phylogenic hierarchy?

(A)       Kingdom, phylum, family, class, order, genus, species

(B)        Phylum, family, order, class, kingdom, species, genus

(C)        Kingdom, family, order, class, phylum, genus, species

(D)       Kingdom, phylum, class, order, family, genus, species

(E)        Family, kingdom, order, phylum, genus, class, species

 

68.       A rattlesnake would be classified as a

(A)       Tertiary consumer and a heterotroph

(B)        Secondary consumer and an autotroph

(C)        producer and an autotroph

(D)       producer and a heterotroph

(E)        primary consumer and a heterotroph

 

69.       At some point in their development, chordates possess all of the following EXCEPT

(A)       A dorsal hollow nerve cord

(B)        A notochord

(C)        Gill slits

(D)       postanal tail

(E)        An exoskeleton

 

Question 70-73

A population of birds (Population A) on a remote, isolated island is studied to determine beak length. The resulting data are plotted in Figure 1.

 

Figure 1

 

 

 

 

Suppose that 200 years later, the beaks of the birds on the island were again measured (Population B). The data, when plotted, yielded a graph as in Figure?

 

Figure 2

 

 

 

70.       What is the average beak length (in cm) of the birds in Figure 1?

(A)       30 cm

(B)        15 cm

(C)        5 cm

(D)       3 cm

(E)        4 cm

 

71.       What is the most likely reason for the difference in distribution of beak lengths between the data plotted in Figure 1 and the data plotted in Figure 1?

(A)       All birds with beaks of 30 mm flew to a new island over the 200 year time span.

(B)        Birds with beaks of 30 mm were selected against.

(C)        Predators consume birds with beaks of 40 mm.

(D)       Birds with beaks of 30 mm were selected for extinction.

 

72.       Suppose that it researcher studying Population B found that birds with beaks of 20 mm were unable to mate with birds that had 40 mm beaks. These two groups of birds would now be classified as

(A)       occupying different niches

(B)        separate species

(C)        competitors

(D)       predators

(E)        separate populations

 

73.       How would beak length in the bird population change after another 200 year time span?

(A)       The average beak length would return to 30 mm.

(B)        The average beak length would shift to 40 mm.

(C)        The average beak length would shift to 20 mm.

(D)       The differences in beak length would more pronounced.

(E)        It is not possible to determine how beak length might change.

 

Question 74-78

Acid rain is formed after the burning of fossil fuels releases compounds containing nitrogen and sulfur into the atmosphere. Sunlight and rain bring about chemical reactions that convert these compounds into nitric acid and sulfur dioxide, which combine with water droplets to form acid rain. Acid rain typically has a pH of approximately 5.5.

 

The higher acidity of soil and water affects many living organisms adversely. As the pH of lake water falls, fish become ill and die. Table 1 shows the effects of pH on the size of adult fish.

 

Table 1

 

pH of lake

average length of fish (cm)

average mass of fish (g)

7.5

30 cm

454 g

7.0

28 cm

450 g

6.5

29 cm

453 g

6.0

25 cm

401 g

5.5

20 cm

288 g

5.0

17 cm

127 g

4.5

all fish dead

all fish dead

 

Mycorrhizal fungi, which form a mutualistic association with many plant roots, are particularly sensitive to the effects of acid rain. These fungi facilitate the absorption of water and nutrients by the plants: in turn, the plants provide sugars and amino acids without which the fungi could not survive.

 

74.       The effect of acid rain on fish size is best represented by which of the following graphs?

 

 

Diagram

 

75.       The relationship between mycorrhizal fungi and plants can best be described as one in which

(A)       one partner benefits from the association and the other partner is harmed

(B)        one partner benefits from the association and the other partner is neither harmed nor helped

(C)        one partner prays upon the other partner

(D)       both partners benefit from the association

(E)        neither partner benefits from the association

 

76.       If the pH of the soil were 7.0, what would be the effect on the mycorrhizal fungi and plants.

(A)       The fungi would survive but the plant would be harmed.

(B)        The fungi would harmed but the plant would survive.

(C)        The fungi would be slightly harmed and the plant would be slightly harmed.

(D)       Neither the fungi nor the plant would survive.

(E)        Neither the fungi nor the plant would be harmed.

 

77.       What might be the best strategy to prevent ecological damage due to acid rain?

(A)       Stock the lakes with bigger fish so that they can resist the effects of the acid better

(B)        Reduce the amount of fossil fuel that are burned.

(C)        Supply plants with excess phosphorus and water

(D)       Supply fungi with excess sugars and amino acids

(E)        Add alkalines to soil and water to neutralize the acid.

 

78.       Fungi are classified as

(A)       prokaryotic decomposers

(B)        eukaryotic producers

(C)        eukaryotic decomposers

(D)       eukaryotic autotrophs

(E)        prokaryotic consumers

 

Question 79-80

The following graphs show the growth of two closely related species of paramecia, both when grown alone (Figure 1) and when grown together (Figure 2). Both species consume bacteria as their food source and reproduce by binary fission as often as several times a day.

 

79.       The data in figure 2 indicate that

(A)       P. aurelia is preying on P. caudata

(B)        P. aurelia is a better competitor than P. caudata

(C)        P. aurelia and P. caudate are in a symbiotic relationship

(D)       P. aurelia is a parasite of P. caudate

(E)        P. aurelia grew better when combined with P. caudata than it did when grown alone

 

80.       Paramecia are members of the kingdom

(A)       fungi

(B)        Animalia

(C)        monera

(D)       protista

(E)        plantae

 

Directions:      Each of the questions or incomplete statements below is followed by five suggested answers or completions. Some questions pertain to a set that refers to a laboratory or experimental situation. For each question, select the one choice that is the best answer to the question and then fill in the corresponding oval on the answer sheet.

 

81.       All of the following are true about RNA EXCEPT

(A)       it is single standard

(B)        its bases are adenine, thymine, guanine, and uracil

(C)        it has a sugar phosphate backbone

(D)       its sugar is ribose

(E)        it is found in the both the nucleus and the cytoplasm of the cell

 

82.       The function of the Golgi appraratus is to

(A)       package and store proteins for secretion

(B)        synthesize proteins

(C)        function in cellular respiration

(D)       help the cell expel waste

(E)        digest foreign substances

 

83.       A eukaryotic cell that has a cell wall but lacks chloroplasts would be classified as a

(A)       moneran

(B)        chordate

(C)        plant

(D)       fungus

(E)        bacteria

 

84.       All of the following could give rise to new species EXCEPT

(A)       Variations in antler size between male and female reindeer

(B)        An earthquake that physically separates a population of lizards into two separate groups

(C)        Divergent evolution

(D)       Evolution of a population of cats such they can no longer mate with their ancestors

(E)        A massive flood that separates a population of frogs onto opposite sides of a large lake

 

85.       A retrovirus requires which of the following enzymes in order to integrate its genome with its host's genome?

(A)       Host’s RNA polymerase

(B)        RNA dependent RNA polymerase

(C)        DNA dependent RNA polymerase

(D)       DNA dependent DNA polymerase

(E)        RNA dependent DNA polymerase

 

86.       Which of the following groups have the most in common with one another?

(A)       Members of the same kingdom

(B)        Members of the same genus

(C)        Members of the same phylum

(D)       Members of the same class

(E)        Members of the same family

 

87.       Which of the following individuals is the LEAST fit in evolutionary terms?

(A)       A 45 year old male with a terminal disease who has fathered three children

(B)        A 20 year old man who has fathered one children

(C)        A 35 year old woman with four children

(D)       A healthy 4 year old child

(E)        A 25 year old woman with one child, who has a tubal ligation to prevent future pregnancies

 

Question 88-92

Most bacteria can be grown in the laboratory on agar plates containing glucose as their only carbon source. Some bacteria require additional substances, such as amino acids, to be added to the growth medium. Such bacteria are termed auxotrophs. These bacteria are denoted by the amino acid they require followed by a “-” in superscript (e.g., arg). Bacteria that do not require that particular amino acid can be indicated by a “+” in superscript.

 

Different strains of bacteria were grown on several plates containing a variety of nutrients. Figure q shows the colonies (numbered) that grew on each plate. The supplements in each plate are indicated.

 

Figure 1

 

 

 

 

In a second experiment, Colony 1 was mixed with soft agar and spread over a plate so that an even lawn of bacteria grew. Bacterial lawns appear cloudy on agar plates. A single drop of an unknown organism was placed in the center of the bacterial lawn and after 24 hours, a clear area known as a “plaque” appeared at that spot. The clear area continued to expand at a slow rate. Although new colonies could be grown from samples taken from the lawn, attempts to grow new colonies from samples taken from the plaque area were unsuccessful.

 

88.       Referring to Figure 1, what is the genotype of Colony 3?

(A)       arg+, leu+, pro+

(B)        arg+, leu-, pro+

(C)        arg+, leu+, pro-

(D)       arg-, leu-, pro+

(E)        arg-, leu-, pro-

 

89.       Is Colony 1 an autotroph?

(A)       Yes, it is able to grow in the presence of the three amino acids being tested

(B)        Yes, it can only grow if glucose is present

(C)        No, it is able to grow in the absence of glucose.

(D)       No, it is able to grow in the absence of any additional amino acids.

(E)        The data available are insufficient to determine the answer.

 

90.       Which structures could be observed in a sample of Colony 2?

I.       Nuclei

II.    Ribosome

III. Mitochondria

(A)       I only

(B)        II only

(C)        I and III only

(D)       II and III only

(E)        I, II and III

 

91.       If a liquid culture medium containing glucose, leucine, and proline was inoculated with Colony 4, would bacterial growth be observed?

(A)       No, Colony 4 is an arginine auxotroph (arg).

(B)        No, Colony 4 cannot, grow in the presence of leucine.

(C)        Yes, Colony 4’s genotype is leu-, pro-.

(D)       Yes, Colony 4 requires only glucose to grow.

(E)        The data available are insufficient to make a prediction.

 

92.       What is the most likely reason for the clearing (the plaque) in the lawn of bacteria in the second experiment?

(A)       The unknown organism-is bacterial Colony 2, and these bacteria are eating the 1acteria from. Colony 1 forming the lawn.

(B)        The unknown organism is a virus that is infecting the bacteria and causing them to lyse (killing them).

(C)        The drop placed iii the center of the lawn contained a strong acid that destroyed the bacteria at that spot

(D)       Bacteria are very delicate and the disturbance caused them to die.

(E)        The unknown organism began producing threonine, which is toxic to Colony 1

 

Question 93-96

In 1910, a small town on the East Coast of the United States relied primarily on agriculture to support its economy. In the mid-1930s, a steel mill was built, and the economy shifted from being agriculturally supported to being industrially supported. The steel mill released a lot of smog and soot into the air, which collected on the bark of trees in a wooded area near the outskirts of town. Over a period of ten years the bark gradually darkened, then maintained a constant dark color.

 

A variety of animals and insects lived in the wooded area. In particular, a certain species of moth served as the primary food source for a population of birds. The moths lay their eggs in the bark of the trees and, thus, must spend a fair amount of time sitting on the tree trunks. Table 1 presents data on the moth population.

 

Table 1

Year

% white moths

% black moths

1910

95

5

1920

95

5

1930

95

5

1940

50

50

1950

20

80

1960

5

95

 

93.       The wings of the moths and the wings of the birds are both used for flight (similar functions); however, their underlying structures are very different. Moth wings and bird wings are hut classified as

(A)       homologous structures

(B)        autologous structures

(C)        divergent strictures

(D)       analogous structures

(E)        emergent structures

 

94.       What is the most likely explanation for the shift in the percentage of black moths in the population?

(A)       The white moths no longer blended, the Color of the tree bark and, thus were selected for.

(B)        The black moths blended better with the color of the tree bark and, thus were selected for.

(C)        The black moths blended better with the color of the tree bark and, thus were selected against.

(D)       The white moths blended better with the color of the tree bark and, thus were selected against.

(E)        The black moths did not blend with the color of the tree bark and, thus were selected against.

 

95.       If a seed from one of the trees was planted in an area far from the steel mill, what color would the bark of the tree be?

(A)       Black, because the parent tree had black bark

(B)        White, because the gene causing black bark was mutated due to environmental pollution

(C)        Black, because the gene causing white bark was mutated due to environment pollution

(D)       White, because the black bark was an acquired characteristic and is there passed on to progeny

(E)        The color of the bark is not able to be determined.

 

96.       Birds track their prey visually, whereas bats rely on sonar to locate their food. If the bird population were replaced with a bat population in 1940, what would eb ratio of white moths to black moths?

(A)       95% white, 5% black

(B)        80% white, 20% black

(C)        50% white, 50% black

(D)       20% white, 80% black

(E)        5% white, 90% black

 

Question 97-100

Dialysis tubing is a semipermeable membrane. It allows small molecules, such as water, to pass through easily, while larger molecules, such as sucrose, are restricted. Movement of molecules across the tubing is due to concentration gradients. In an experiment designed to study osmosis, several pieces of dialysis tubing were filled with sucrose solutions of varying concentration and placed in beakers containing distilled water. The rate and direction of water movement was determined weighing the bags before and after placing them in the distilled water. The data are recorded below.

Table 1

Tube number

Tube contents (breaker contents)

Mass (g)

0 minutes

Mass (g)

15 minutes

Mass (g)

30 minutes

Mass (g)

45 minutes

Mass (g)

60 minutes

            1           

Distilled water (distilled water)

22.3 g

22.4 g

22.2 g

22.3 g

22.3 g

            2           

100% sucrose (distilled water)

24.8 g

25.3 g

25.7 g

26.4 g

26.9 g

            3           

40% sucrose (distilled water)

25.1 g

26.3 g

27.5 g

28.9 g

29.6 g

            4           

Distilled water (40% sucrose)

22.7 g

21.3 g

20.5 g

19.8 g

18.7 g

 

97.       Why does the mass of Tube 3 increase while the mass of Tube 4 decreases?

(A)       Water moving into Tube 3 and sucrose is moving into Tube 4.

(B)        Water is moving into Tube 4, and sucrose is moving into Tube 3

(C)        Water is moving into Tube 3, and water is moving out of Tube 4.

(D)       Sucrose is moving into Tube 3, and sucrose is moving out of Tube 4.

(E)        Sucrose is moving out of Tube 3, and water is moving out of Tube 4.

 

98.       Why does the mass of Tube 1 remain relatively unchanged throughout the experiment?

(A)       The dialysis tubing in Tube 1 is defective and does not allow water to cross.

(B)        There is no concentration gradient to drive the movement of sucrose.

(C)        The dialysis tubing broke, allowing the tube contents to mix with the beaker contents.

(D)       There is no concentration gradient to drive the movement of water

(E)        The experiment failed to record the date properly.

99.       Which of the following graphs best illustrates the relationship between Tube 2 and Tube 3?

 

 

 

Diagram

100.   Cell membranes are also semipermeable, allowing water but not other substances to cross easily. A red blood cell placed in a 0.9% NaCl solution will neither swell nor shrivel. Based on this knowledge, and the information presented in Table 1, what would happen to a red blood cell placed in a 20% NaCI solution?

(A)       Water would be drawn out of the cell and the cell would swell.

(B)        Water would be drawn into the cell and the cell would swell.

(C)        Water would be drawn out of the cell and the cell would shrivel.

(D)       Water would be drawn into the cell and the cell would shrivel.

(E)        No change would occur to the cell.


 

Answers and Explanations

Question

Answer

Explanation

              1           

B

Prokaryotes (bacteria, monerans) have no membrane-bound organelles, so all reactions and processes occur in the cytoplasm. You should have been able to eliminate choice C, A and e because they did not describe locations.

              2           

D

When muscle cells run out of oxygen and switch to anaerobic metabolism (glycolysis only) to make ATP, the end product is lactic acid. Yeast can also switch to anaerobic metabolism; their end product is ethanol. You should have been able to eliminate choices A and B because they are not products.

              3           

B

Eukaryotes possess organelles and as such divide the location of their cellular processes among them. Glycolysis occurs in the cytoplasm, whereas the Krebs cycle and electron transport occur in the mitochondria. As in Question 1, you should have eliminated choices C, D and E.

              4           

E

Recombination occurs when the homologous chromosomes are paired and crossing over can take place. This occurs during prophase I of meiosis. Remember that recombination occurs during prophase, and this would help you eliminate choices A, B and D.

              5           

B

After prophase I, the homologous chromosomes remain paired and align at the center of the cell, on the “metaphase plate.” (The prefix meta means “middle.” Use this fact to help you elimate choices A, C and E.) During metaphase II, the individual, unpaired chromosomes align at the cell center.

              6           

A

During meiosis, the chromosomes remain replicated (i.e., remain as two jointed sister chromatids) for the entire first set of divisions. The whole point to the second set of meiotic divisions is to separate the sister chromatids. This takes place during and phase II.

              7           

D

Habituation involves becoming accustomed to certain stimuli that are not harmful or important. For example, if you walk down the hallway and a friend jumps out at you and you get scared, that is a normal reaction to a startling stimulus. However, if this happens every time you walk down the hallway, you get accustomed to it and no longer are startled. You have become habituated to the stimulus. Note that for Questions 7-9, you just had to know the basic definitions of these types of learning. Most of the classification type questions are like that.

              8           

B

Some animals do not have an instinctive sense for who their mother is and will bond with any object they are exposed to during a certain time period after their birth. The “imprints” on their minds, and thereafter, even if exposed to their real mother, they will still treat the object as Mom.

              9           

C

Conditioning involves the association of and response to one stimulus with a second, different stimulus. The best example is Ivan Pavlov’s dog. He rang a bell when he fed them, and the dogs salivated in response to the food. Soon, all he had to do was ring the bell, and the dogs would salivate, even in the absence of food.

            10         

A

Most digestion and absorption occur in the small intestine. A very small amount of digestion (starch only) takes place in the mouth, and a very small amount of digestion takes place in the stomach (acid hydrolysis of food and some protein digestion). As with Questions 7-9, Question 10-11 require the same type of knowledge - memorization of basic facts.

            11         

E

Saliva contains the enzyme amylase, which breaks down starch.

            12         

C

Cells in the stomach secrete hydrochloric acid, which keeps the pH of the stomach around 1-2, the other regions of the digestive tract maintain a fairly neutral pH.

            13         

A

Divergent evolution occurs when the same ancestral organism is placed into different environments and must then adapt to function in these different environments. Thus the same original structures evolve separately and “diverge” from one another. Examples of homologous structures are the arm of a man, the wing of a bat, and the flipper of a whale. All have the same basic bone structure but vastly different functions. The opposite of divergent evolution is convergent evolution, in which vastly different organisms are placed into the same environment and must adapt to perform similar functions with different structures. Convergent evolution produces analogous structures, examples of which are the wings of bats, the wings of butterflies. Speciation is often the result of divergent evolution, not the cause of it

            14         

C

The job of the blood is to carry oxygen from the lungs, where it is plentiful, to the tissues, where it is not. Thus hemoglobin should have a high affinity for oxygen in the lungs so it can bind oxygen (choices A, B and D could be eliminated) and a low oxygen affinity in the tissues (so it can release the oxygen where it is needed). The reverse is true for carbon dioxide. Hemoglobin has a high carbon dioxide affinity in the tissues and a low carbon dioxide affinity in the lungs.

            15         

D

In RNA, the base thymine (T) is replaced with uracil (U), so choice A can be immediately eliminated. Further, A will always pair with U, and G will always pair with C. The only choice that has the bases paired correctly is choice D.

            16         

B

Choices A, C, D and E all describe characteristics of the phylum arthropoda. A water vascular system is a characteristic of the phylum echinodermata, the “spiny skinned” animals such as sea stars and sea urchins. Their water vascular system ends in tube feet that play a role in locomotion and feeding. Don’t forget your LEAST/EXCEPT/NOT technique of circling the word “EXCEPT” and drawing a vertical line through the answer choices to help you remember to choose the incorrect statement.

            17         

E

The kidney’s primary role is to filter blood to remove wastes (statement I is true and choice D is eliminated), but it is also involved to a fair extent in blood pressure regulation (through renin and aldosterone, so II is true and choices A and C are eliminated) and in pH regulation through excretion of hydrogen ions, so III is true and choice B is eliminated).

            18         

D

If a pure-breeding long-tailed chicken (TT) mates with a pure-breeding short-tailed chicken (tt), all of their offspring (the F1 generation) will have the genotype Tt (and have long tails). Thus all of them, if mated with the correct genotype (Tt or tt), could produce offspring with short tails. Draw some quick Punnett squares to prove it to yourself.

            19         

B

Density-dependent factors are those that get more significant as the size of the population increases. Limited nutrients and water, toxic waste build-up, and predation are all issues that are of greater concern to a large population that to a small one. Only choice B, climate temperature, is not more worrisome to a large group than to a small one. It, will affect all populations equally, regardless of their size. Remember your LEAT/EXCEPT/NOT technique.

            20         

C

Two populations are considered separate species when they are so different from one another that they can no longer mate and produce viable offspring. Thus, organisms that can mate with each other must be of the same species.

            21         

E

Blood that is poor in oxygen returns from the body to the right side of the heart (I is true, so choices B and C are eliminated), then travels through the pulmonary artery (III is true, so choices A and D are eliminated) to get to the lungs, where it picks yup oxygen again. This oxygen-rich blood returns to the left side of the heart through the pulmonary vein (II is false) and is pumped back out to the body through the aorta.

            22         

B

The characteristics described are those of the phylum annelida, the best example of which is the earthworm. Mollusks have external shells (snails), echinoderms and arthropods have exoskeletons (sea stars, crustaceans, insects), and chordates have endoskeletons and, in any case, are not worms.

            23         

A

The light reactions of photosynthesis convert solar energy to usable energy in the form of ATP (choices C and E are eliminated) and NADPH (a reduced electron carrier). The ATP and NADPH (i.e. energy) produced during these reactions are used later during the Calvin cycle to fix carbon dioxide into carbohydrates, like glucose. Because glucose is a product of the light-independent reactions, choice B could be eliminated. Remember that NADPH belongs with photosynthesis to eliminate choice D.

            24         

C

When the concentration of substrate far exceed the concentration of enzyme (remember, the question states that enzyme concentration is assumed to be constant), all the enzyme active sites are saturated with substrate, and the product is being formed at its maximum rate. The only way to increase product formation at this point is to increase the concentration of the enzyme. Note that enzymes should not be used up in the course of the reaction (A is wrong). Furthermore, product formation is still occurring, just at a stable rate (B and D are wrong). There is no reason to assume an inhibitor has been added; the rate of product formation remains constant.

            25         

D

Berries are plant products (i.e. primary producers), thus any organism that eats berries is a primary consumer, on an herbivore (I is true, choices B, C and E can be eliminated). Notice at this point that the only remaining choices (A and D) do not contain option III, therefore, option III is false. Secondary consumers, carnivores and omnivores (e.g. birds) eat primary consumers (e.g. bugs), thus II is also true, and choice A can be eliminated. Terriary consumers are carnivores (e.g. cats) that eat other carnivores (e.g. birds, secondary consumers). III is false, as we saw earlier.

            26         

B

Carbohydrate have the general molecular formula C6H2nOn, as in glucose, which is C6H12O6. The only formula that fits this rule is choice B.

            27         

C

A change in a population that occurs over a long period of time is evolution. This alone is a good tip-off that choice C, the only choice that mentions evolution, is correct. Speciation has not occurred, only a change in the characteristic of the birds, thus choices A and D can be eliminated. Any change in the fitness of the insects would change the characteristics of the insect population, not the bird population (B is wrong), and random mutation would not produce a specific, directed effect (E is wrong). Birds with large beaks had greater fitness because they could more easily obtain food, thus they had an advantage over birds with smaller beaks, which dies out as tie passed.

            28         

E

The other choices do not describe substrate binding sites on an enzyme.

            29         

D

Break this question down one piece at a time. First, the question states that there is a high sodium concentration outside the cell. This means sodium wants to move into the cell (where concentration is lower). Choices A and C can be eliminated because they state that sodium would move out of the cell. Active transport requires ATP, and because there is no ATP involved, choice E can be eliminated. Last, because sodium moves across the membrane with the help of a channel, it is moving by facilitated diffusion (choice B is eliminated).

            30         

E

Decomposers take organic material and break it down into its individual compounds, thus returning these compounds back to the earth. The other processes listed are carried out by other organisms: nitrogen fixing bacteria (choice A), heterotrophs and autotrophs (choice B), and other soil bacteria (choice C and D)

            31         

B

The endocrine system is a body control system, but it is NOT rapid. The fastest hormone in the body is adrenaline, and even that takes a few seconds, compared the nervous system’s milliseconds. Most hormones operate in the minutes to hours range. The other choices regarding the endocrine system are all true. Remember your LEAST/EXCEPT/NOT technique!

 

            32         

B

This symbiotic relationship describes commensalism. In mutualism both partners benefit, in parasitism and predator prey relationships one partner benefits while the other is harmed, and symbiosis is just a general term used to describe close living arrangements.

 

            33         

D

Relationships that are directly proportional have linear graphs with a positive slope.

            34         

B

Male haploid cells (pollen grains or microspores are produced on the anther (#2 in the diagram), which is at the tip of the filament (#3 in the diagram).

            35         

A

Pollen grains stick to the stigma (#1 in the diagram), which is supported by the style (#4 in diagram).

            36         

E

The pollen fertilizes the ovule (female haploid cells, or megaspores, # 6 in the diagram); once fertilized, the ovary (#8 in the diagram) develops into a fruit.

            37         

C

The prefix photo refers to light; because the light is growing toward light we can eliminate choices A, D and E. “Positive” means growing toward, so choice B can be eliminated.

            38         

A

The prefix geo refers to the earth, or soil’ thus we can eliminate choices C, D and E. because the plant is growing away from the earth, this is a negative tropism and we can eliminate choice B.

            39         

D

A surge in LH is what causes ovulation and is measured in the ovulation prediction kits. Estrogen and progesterone affect the uterus, not the ovary, and FSH causes development of a follicle (A, B and C are wrong). Testosterone is a male hormone (E is wrong).

            40         

BH

Because we know hormone X is peaking at ovulation time, a quick look at the graph shows hormone X peaking at about Day 14 of the cycle.

            41         

A

The rise in hormone Y occurs after ovulation (choice E is wrong) and coincides with formation of the corpus luteum (choices B and D are wrong). The primary hormone secreted by the corpus luteum is progesterone.

            42         

E

Rapid cell division after fertilization is known as cleavage. Blastulation is the formation of a hollow ball of cells (A is wrong), gastrulation is formation of the three primary germ layers (B is wrong), neurulation is development of the nervous system (C is wrong), and implantation is when the morula (solid ball of cells) burrows into the uterine lining (D is wrong).

            43         

C

You should remember the prefixes anto, meso, and endo for the primary germ layers and therefore eliminate choices D and E right away. The ectoderm forms the skin, hair, nails, mouth lining and nervous system. The mesoderm forms muscle, bone, blood vessels, and organs (B is wrong). The endoderm forms inner linings and glands (A is wrong).

            44         

B

The development of a thriving ecosystem from a barren area is known as succession. Note the evolution usually has a much longer time frame than succession.

            45         

B

The climax community is the final, stable community in secession. The key word here is “stable.” That should tip you off that this is the end of the process, or the “climax.”

            46         

D

The first organisms to colonize a barren area are known as the pioneer organisms.

            47         

A

Diuretics help eliminate water (i.e., increase urine production) from the body. From the data tables, the only substance that increases urine production significantly is caffeine. Don’t forget the I, II, III technique here; even just knowing that option I is true allows you to eliminate two (choices B and D) of the five choices.

            48         

A

Again, from the data tables, there is a directly proportional (i.e., linear) relationship between the amount of caffeine ingested and the volume of urine produced. As caffeine ingested and the volume of urine produced. As caffeine consumption increases, so des urine volume. The only graph that shows this relationship is choice A.

            49         

C

Because the caffeine and the sodium chloride were dissolved in water, plain, water was consumed as a control, to make sure the effects seen were due to the added substances and not the water. Questions about experimental controls come up fairly frequently on the SAT Biology E/M. Subject Test; make sure you know the definition for a control and how to spot in the experiment.

            50         

C

From Table 2, an increase in sodium chloride of 0.9 g results in a decrease in urine volume of approximately 40 ml. when 3.6 g sodium chloride are ingested, 82 ml urine is produced; thus if 4.5 g sodium chloride were to be ingested, the expected urine volume would be 40 ml less, approximately 40 ml.

            51         

B

As soon as you see “hemophilia,” you should be thinking “X-linked disorder.” Then use the technique for avoiding the temptation trap, which is particularly dangerous here, because the passage and the questions are confusing, and it’s very tempting to just guess blindly. Resist! Take the paragraph apart piece by piece, sentence by sentence. Write out genotypes as you read through and construct Punnett squares to help you see probability. Out of this family, the only members that express this condition are males. This is a tip-off for X-linked disorders, which are more common in males because they have only a single X chromosome. (In any case, you should remember the two most common X-linked disorders; hemophilia and color blindness). John’s genotype is YXh. He passed his Y chromosome to Mark and Mike; they also received a normal X from Jane, thus they do not have hemophilia, nor can they pass it on to their kids. Molly and Mary received Xh from John but also received a normal X from Janem thus they are carriers of hemophilia but do not display its symptoms.

            52         

A

Because Mike does not carry the gene for hemophilia (see above), he cannot pass it on to his children, and they in turn cannot pass it on to their children.

            53         

D

Mark and Mike does not carry the gene for hemophilia (see solution to 51 above), thus we can eliminate choices A, B, and E. Jane is normal, so choice C is eliminated as well.

            54         

C

From Table 1, substance B caused on increase in serum calcium levels, which is the effect that insulin has on the body.

            55         

E

Again, from Table 1, substance A caused on increase in serum calcium levels, which is the effect that insulin has on the body.

            56         

B

Substance D causes an increase in serum sodium, which is the effect aldosterone has on the body. Aldosterone is released when blood pressure is low, because excess sodium will have the effect of causing water retention, which will increase blood volume, which will increase blood volume, which will increase blood volume, which will increase blood pressure. (Note: Even if you did not know this, you should have been able to eliminate the other choices.)

            57         

E

The change in serum sodium after injection of Substances B is insignificant. All other choices cause significant change from the baseline values of the variable being measured. Don’t forget the LEAST/EXCEPT/NOT technique.

            58         

C

Cell Type A has no nucleus. The only organisms that do not have nuclei are bacteria (kingdom Monera).

            59         

E

Cell Type C has a nucleus, a cell wall, and chloroplasts and therefore most likely comes from a plant. Equations II and II are the equations for photosynthesis and would occur in plants (choices A, B, and C are eliminated), and equation I is the equation for cellular respiration, which also occurs in plants (choice D is eliminated).

            60         

D

This is a great question to do some answer predicting on. At Time I the oxygen was removed from the cultures and cell Type C died. Clearly it is an obligate aerobe. Thus we can eliminate choices A, B, and C. Because cell Type B was growing well in the presence of oxygen, it cannot be an obligate anaerobe, thus choice E is eliminated. Cell Type B must be a facultative anaerobe, suing oxygen when kit is available and fermenting when oxygen is not available. The decrease in growth of cell Type B after Time I is most likely because energy is produced during fermentation than during aerobic metabolism.

            61         

E

These are the characteristics of desert.

            62         

B

These are the characteristics of taiga.

            63         

C

These are the characteristics of tropical rain forest.

            64         

A

These are the characteristics of tundra.

            65         

D

Flowering plants are angiosperms. Gymnosperms are confiders (naked seed plants; C is wrong), bryophytes are mosses (A is wrong), and tracheophytes are non-seed producing plants (ferns; B is wrong). “Endosperm” is not a classification for plants.

            66         

A

If an organism’s environment remains absolutely constant, and that organism still exhibits regular rhythms of activity there must be some internal “clock” that keeps it on schedule (C and E are wrong). Roosters vary the time of their crow as the sun varies the time it rises (B is wrong). ‘The magnetic field has nothing to do with internal clocks (D is wrong).

            67         

D

Remember: “King Philip came Over From Germany – so?” or make up you own!

            68         

A

Rattlesnakes are clearly heterotrophs (only photosynthetic organisms are autotrophs), so we can eliminate choices B and C. Rattlesnakes are carnivores, not producers (D is wrong) or primary consumers (herbivores, so E is wrong).

            69         

E

Remember your LEAST/EXCEPT/NOT technique. There are four features present in al chordates – dorsal nerve cords (choice A), notochords (choice B), gill slits (choice C), and postnatal tails (choice D). Note that some of these features may be found only in embryonic or larval stages. The “wrong” answer is choice E _ note all chordates (for example, sea squirts and lancelets) have a bony endoskeleton.

            70         

D

The question asks for the average beak length in cm, but the graph gives it in mm. Average beak length is 30 mm. 10 mm = 1 cm; therefore, 30 mm =  cm. read the questions carefully!

            71         

B

Clearly the birds with 30 mm beaks were not surviving too well. There is no reason to assume they flew to another island; remember, they are on a remote, isolated island. There may not be another island near enough to fly to (Asis wrong). If predators consumed birds with 20 mm or 40 mm beaks they would not be the prevalent populations in Figure 2 (C and D are wrong), and if birds with 30 m beaks were selected for, the population would  not have been divided (E is wrong).

            72         

B

The defining characteristic for speciation is an inability to interbreed.

            73         

E

Just because we have some information about how the population change in the last 200 years, it doesn’t tell us how it may change in the next 200 years. It would depend on how the environment changed during that time period.

            74         

D

As the acidity increases (pH goes down), the average mass of the fish decreases. How-ever, it does not decrease linearly; rather, it says constant for a while, then gradually drops off, then rapidly drops off as acidity becomes severe. The best representation of this is choice D.

            75         

D

The plant benefits by easier availability of water and phosphorus, and the fungi benefit by receiving amino acids and sugars. Another term for this type of relationship is mutualism.

            76         

E

pH 7.0 is neutral, thus neither the plant nor the fungi would be harmed.

            77         

B

The best way to prevent damage from acid rain would be to prevent its formation by reducing the burning of the fossil fuels that cause it. There is no guarantee that bigger fish will resist the acidity any better than smaller fish (A is wrong), supplying plants with sugars and amino acids will not help them overcome the effects of acid soil (D is wrong), and, even if alkalines will neutralize acid, they might be just as harmful to the environment (E is wrong)!

            78         

C

Fungi are euakryotes (A and E are eliminated), and they are not photosynthetic (B and D are eliminated).

            79         

B

Clearly P. Aurelia can compete better and get more food that P. caudate; thus it will grow while P. caudate is competed to extinction. Choice A is highly unlikely because the good source the paramecia prefer is bacteria, not each other. This is not a symbiotic relationship but a competitive one (C and D are eliminated), and the data contradict choice E.

            80         

D

Paramecia are single-celled eukaryotes, members of kingdom Protista.

            81         

B

RNA bases do not include thymine; they are adenine, guanine, cytosine, and uracil. All other statements about RNA are correct. Remember the LEAST/EXCEPT/NOT technique!

            82         

A

Ribosomes synthesize protein (B is wrong), mitochondria function in respiration (C is wrong), vacuoles help expel waste (D is wrong), and lysosomes function in digestion (E is wrong).

            83         

D

Choices A and E are prokaryotic and can be eliminated. Chordates have no cell walls (B is wrong), and plants have chloroplasts (C is wrong).

            84         

A

The defining characteristic for speciation is an inability to interbreed. Choices B, C, D, and E could all ultimately produce two different populations that lack the ability to mate. Choice A would not lead to an inability to mate. Remember this is a LEAST/EXCEPT/NOT questions.

            85         

E

A retrovirus has an RNA genome, so its polymerase must be able to read RNA (DNA-dependent choices C and D can be eliminated). Furthermore, retroviruses go through the lysogenic life cycle, and so must insert their genome into their host’s genome. Because all other organisms have a DNA genome, a DNA copy of the viral (RNA) genome must be synthesized. A DNA polymerase is needed (choices A and B can be eliminated). Note that the host’s RNA polymerase is DNA dependent, the same answer as choice C.

            86         

B

The members that have the most in common with one another are the members near the bottom of the hierarchy. Of the choices given, genus is the closest to the bottom of the hierarchy.

            87         

D

Anyone who has produced offspring has demonstrated their fitness. Regardless of how healthy a child is, he has not yet produced offspring to prove his fitness. Use the LEAST/EXCEPT/NOT technique.

            88         

C

The only plate that Colony 3 cannnot grow on is Plate C, which lacks proline. Thus colony 3 requires proline to row and is a proline auxotroph (pro). This eliminates choices A, B, and D. Choice E is incorrect because Colony 3 does not require arginine or leucine to grow; it can grow just fine in the absence of these amino acids, as is indicated on plates A and B.

            89         

D

Colony 1 can grow on any of the plates, thus it does not require any additional amino acids. Auxotrophs require additional supplements to their growth media.

            90         

B

Because these are bacterial colonies, they would not have any membrane-bound organelles, and thus no nuclei (choices A, C, and E can be eliminated) or mitochondria (choie D can be eliminated). Bacteria do have ribosomes to synthesie proteins.

            91         

A

It really helps to predict an answer BEFORE you look at the answer choices. Sometimes looking at the choices first can confuse your thinking and lead you to a trap, but if you have an idea of the correct answer before you look at the choices, you will be less tempted. Colony 4 cannot grow in the absence of arginine as is evidenced by Plate B. thus, because the liquid medium does not contain arginine, no bacterial growth would be observed.

            92         

B

Again, try to predict an answer first. Clear spots lawns of bacteria are due to infection by viruses that cause lysis of the bacteria. Even if this was not obvious to you, you should have been able to eliminate the other choices. There is no reason to assume Colony 2 would prey on Colony 1 (A is wrong); strong acid would lyse and destroy the Bacteria immediately, not after 24 hours (C is wrong); bacteria are not delicate, they can grow just about anywhere, under any conditions (D is wrong); and there is no data to support fact that threonine may be toxic to the bacteria or that the “unknown organism” was producing it.

            93         

D

Structures with similar functions but different underlying structures are the result of vastly different organisms being placed into similar environments and having to adapt to the same stresses with different starting materials. These are termed “analogous structures” and are the result of convergent evolution. (See also Questions # 13).

            94         

B

Because the percentage of black moths is increasing, they must be selected for. This eliminates C and E. because the percentage of white moths is decreasing, they must be selected against, eliminating choice A. choice D is wrong because white moths would not blend better against dark tree bark.

            95         

D

The original parent had white bark. The change in bark color is the result of an accumulation of soot on the tree. This is an acquired characteristic and would not be passed on to offspring. Seedlings that grew far from the plant would not be exposed to soot in the air and would not experience discoloration of their bark.

            96         

C

The reason the percentage of black moths increased was because they were no longer visible against the now darkened bark of the trees. Because the white moths were more easily seen by the birds, their numbers declined. However, because bats rely on sonar to locate prey instead of vision, darker coloring would not give the moths any advantage, and the population percentages would stay at the point they were at when the birds were replaced by bats, a fifty-fifty split.

            97         

C

Sucrose cannot cross the dialysis membrane, so it cannot cause any effect on the mass of the tubes. This eliminates choices A, B, D, and E.

            98         

D

Because movement across the membrane relies strictly on concentration gradients, the fact that there is no gradient in Tube 1 would prevent the movement of water into or out of the tube thus there would be no change in miss.

            99         

B

The gradient in Tube 3 is much larger than the gradient in Tube 2, thus water would be expected to enter more rapidly. This is confirmed by the data in Table 1. A linear graph should show two lines with positive slopes, and the slope of Tube 3’s line should be greater than the lope of Tube 2’s line.

          100       

C

The fact that the cell does not swell or shrivel in 0.9% NaCl implies that there is no concentration gradient. A cell in a 20% NaCl solution would experience similar stresses to a dialysis tube filled with water sitting in a beaker filled with a more concentrated solution, such as Tube 4. The data indicate that Tube 4 lost mass, thus water exited the tube, and the same would happen to the red blood cell.

 

2ND DIAGNOSTIC TEST

 

1.           Sexually reproducing organisms show greater variation than a sexually reproducing ones because

 

(A)       they exhibit fewer mutations

(B)        they exhibit a greater mutation rate

(C)        a sexually reproducing organisms do not have internal membranes.

(D)       their alleles recombine

(E)        they are larger

 

2.           Several species of rhododendron are growing in the same area. All of the plants are capable of hybridization, but none ever do because some of the plants produce pollen in early June while others produce pollen in late June. This best describes an evolutionary process known as

 

(A)       Survival of the fittest

(B)        Overpopulation

(C)        Reproductive isolation

(D)       Artificial selection

(E)        Stabilizing selection

 

3.           All of the following contribute to variation in a population EXCEPT

 

(A)       Mutation

(B)        Isolation

(C)        Sexual reproduction

(D)       Conjugation

(E)        Genetic drift

 

4.           Oxygen released by plants comes from

 

(A)       Air

(B)        Carbon dioxide

(C)        Glucose

(D)       Chlorophyll

(E)        Water

 

5.           All of the following are mammals Except

 

(A)       tiger

(B)        ape

(C)        kangaroo

(D)       blue jay

(E)        duck-billed platypus

 

6.           Which of the following is a density-independent factor?

 

(A)       Disease

(B)        Famine

(C)        Floods

(D)       Predation

(E)        Increase in toxins in the environment

 

7.           A gene pool in a population of jackrabbits in a field remained constant for many generations. The most probable reason for this stable gene pool it that

 

(A)       no migration occurred in a large population with random mating and no mutation

(B)        no migration occurred in a small population with random mating and no mutation

(C)        no migration occurred in a large population with nonrandom mating and no mutation

(D)       there was much migration into and out of the large population, but matting was random and there were few mutations.

(E)        the population was small with no mutations, no migrations, and nonrandom mating.

 

8.           All of the following about plasma membrane structure and function arc correct EXCEPT.

(A)       All plasma membranes have the identical composition and structure

(B)        Diffusion of gases across a membrane require that the membrane be moist

(C)        Facilitated diffusion is an example of passive transport.

(D)       proteins serve as membrane channels.

(E)        plasma membranes contain receptors that are specific for the molecules they uptake

 

9.           Which of the following exhibits internal fertilization, external development of the embryo, few eggs, and much parenting?

(A)       Mammals

(B)        Amphibians

(C)        Reptiles

(D)       Birds

(E)        Fish

 

10.       A solution with a pH of 5 is ____ times more acidic than a solution a pH of 7.

(A)       1/10

(B)        1/100

(C)        10

(D)       100

(E)        1,000

 

11.       Vitamins are essential for normal cell function. They are important because they

(A)       function as an energy source

(B)        are hormones

(C)        directly assist in the normal conduction of impulses

(D)       resist pH changes

(E)        enable enzymes to function normally

 

12.       Tendons connect ________ to ________: ligaments connect ________ to ________.

(A)       bone to bone; bone to muscle

(B)        bone to muscle bone to bone

(C)        bone to bone; muscle to muscle

(D)       muscle to muscle; bone to bone

(E)        ligaments to bone; tendons to 6 ones

13.       Food chains never consist of more than 4 or 5 trophic levels: The reason for this is

(A)       energy is lost along the food chain

(B)        there are fewer primary consumers in the world than secondary consumers

(C)        producers are always shown on the bottom of any food chain

(D)       pioneer organisms compete with consumers

(E)        all of the above are correct

 

14.       Here is a sketch. All of the fol1owin processes produce this molecule EXCEPT the

 

 

 

 

 

 

 

 

Diagram

 

(A)       Calvin cycle

(B)        Krebs cycle

(C)        electron transport chain

(D)       light dependent reactions

(E)        glycolysis

 

15.       A black animal as crossed with a white animal an all the offspring are black. Which pattern of inheritance nr likely at work?

 

(A)       Law of dominance

(B)        Law of segregation

(C)        Incomplete dominate

(D)       Codominance

(E)        Sex linked inheritance

 

16.       According to the best scientific evidence about evolution, species descended from a common ancestor.

 

(A)       Slowly and gradually by the accumulation of many small changes

(B)        rapidly through divergent evolution alone

(C)        rapidly through mutation alone

(D)       in spurts of relatively rapid change

(E)        because they needed to adapt to a changing environment or they

 

17.       A black h is crossed with a white rooster and only gray offspring result If two of these ray offspring are mated, what is the chance of hatching a white offspring

 

(A)       0%

(B)        25%

(C)        50%

(D)       75%

(E)        100%

18.       Farmers have successfully bred Brussels sprouts, broccoli, kale, and cauliflower from the mustard plant. This demonstrates

 

(A)       convergent evolution.

(B)        coevolution

(C)        adaptive radiation

(D)       natural selection

(E)        artificial selection

 

Questions 19-21

 

(A)       imprinting

(B)        Classical condition

(C)        Fixed action

(D)       Altruism

(E)        Operant condition

 

19.       Geese hatching follow the first thing they see

 

20.       Innate, highly stereotypical behavior, which, once begun, is continued to completion no matter how useless

 

21.       Trial and error learning

 

22.       Scientists believe chat the giraffe original had a short neck that has grown long over time. The most likely explanation of this is which of the following?

 

I.       Natural selection

II.    Adaptive radiation

III. Divergent evolution

 

(A)       I only

(B)        I and II only

(C)        I and III only

(D)       II and III only

(E)        I, II, and III

 

23.       Which of the following are most closely

 

I.       Acer rubrum

II.    Acer sucte

III. P.seudorricon nubrum

 

(A)       I and II

(B)        II and III

(C)        I and II

(D)       All are closely related.

(E)        It cannot be determined using only scientific names.

 

Question 24-26.

Refer to this drawing of the eye.

 

 

Diagram

 

24.       Identify the structure that change to allow different amounts of light to enter the eye.

 

25.       Identify the structure that absorb light and sends nerve impulses to the brain.

 

26.       Identify the retina

 

Question 24-26.

 

Five beakers are used in an experiment about osmosis. Each beaker contains 50 mL of sucrose solution of varying concentrations: 0.2 M 0.4 M 0.6 M, 0.8-M, 1.0 M. Pieces of fresh potato (each 10.0 g in mass) are cut up weighed, and plated into the beakers. After 12 hours the potatoes are crefu1ly removed from each beaker and weighed again. Sec the data in the table below.

 

Beaker

Concentration of sucrose solution

Mass of Potato at Time Zero

Mass of Potato After 12 Hours

                                 1           

1.0 M

10.0 g

8.2 g

                                 2           

1.8 M

10.0 g

9.4 g

                                 3           

0.6 M

10.0 g

3.8 g

                                 4           

0.4 M

10.0 g

11.5 g

                                 5           

0.2 M

10.0 g

13.5 g

 

27.       In this experiment

 

(A)       water flowed into the potato only

(B)        water flowed out of the potato

(C)        sucrose flowed into the potato only

(D)       sucrose flowed both into and out of the potato

 

28.       given the result of this experiment what is the molarity (concentration) with the potato cells?

 

(A)       Less than 0.2 M

(B)        Less than 0.4 M but greater than 0.2 M

(C)        Less than 0.6 M but greater than 0.4 M

(D)       Less than 0.8 M but greater than 0.6 M

(E)        Greater than 0.8 M

 

29.       The results of this experiment give support to the theory that

 

(A)       water diffuses down a gradient

(B)        water can be actively transported against a gradient

(C)        solutes will diffuse from high concentration to low concentration

(D)       living cells respond in different ways to the same condition

(E)        potato ceil respond differently of mother living cells

Question 36-39

 

Refer to this graph of an impulse passing across a neuron.

 

 

 

Diagram

 

36.       The impulse is passing

 

37.       The sodium-potassium pump is responsible for pumping ions across the membrane

 

38.       A steep gradient of sodium and potassium ions exists at the axon membrane

 

39.       An impulse cannot pass

 

Question 40-41

 

A study of a small farm in Michigan was carried out in 2004. A variety of organisms to live there, including meadow voles, grasshoppers spiders, birds, and mice. The farmer retired and moved away, leaving the land to grow wild.

 

40.       The meadow voles, grasshoppers, spiders, mice, and other organisms, along with the soil, minerals, and water make up a(n)

 

(A)       Ecosystem

(B)        Population

(C)        Community

(D)       food chain

(E)        desert biome

 

41.       The study of the farm revealed the population size of the different species of animals during the summer months of June July, and August. The results are recorded in the table below

 

 

Number of Organisms

Species of animals

June

July

August

Spiders

850

300

550

Grasshoppers

1,600

4,600

4,000

Mice

275

225

250

Birds

95

80

90

 

Which is correct about the data collected from June to August?

 

(A)       Only the spider population changed to any extent

(B)        The population of mice increased as summer went or

(C)        The population of grasshoppers remained constant:

(D)       The population of birds remain fairly constant

(E)        Both the population of spiders and mice remained constant.

 

42.       What will most likely occur if the farm is sold and the fields are allowed to grow wild?

 

(A)       The plant will change, but the animals will stay the same.

(B)        They animals will change, but the plants will stay the same

(C)        Neither the plant not the animals will change because the climate will not change.

(D)       Both animals and plants will change.

(E)        All will slowly die out because they will not be adapted to the new environment.

 

43.       Although several different species of birds inhabit the farm, competition between these birds rarely occurs. The best explanation for this lack of competition is that these birds

 

(A)       share food with each other

(B)        have a limited red supply of food

(C)        live in different ecological niches

(D)       are closely related

(E)        have experienced mutations in their DNA that prevent them from competing

 

44.       Humans eat corn and eat other vegetables. Humans also eat beef from cattle that were corn fed. In those cases, cattle and humans occupy which of the following trophic levels?

 

(A)       Producer and primary consumer

(B)        Primary consumer and secondary consumer

(C)        Secondary consumer and tertiary consumer

(D)       Tertiary consumer and quaternary consumer

(E)        Both are primary

 

Questions 45-47

 

(A)       Tundra

(B)        Marine biome

(C)        Desert

(D)       Temperate deciduous forest

(E)        Tropical rain forest

 

45.       Only 4 percent of the land surface but accounts for 20 percent of Earth’s food production

 

46.       Provides most of Earth’s food and oxygen

 

47.       Consists of trees that drop their leaves in winter

 

Question 48-51

 

Refer to the diagram of a flower

 

 

 

 

 

Diagram

 

48.       Site where the pollen germinates

 

49.       Sire of sperm production

 

50.       Becomes the fruit

 

51.       Becomes the seed

 

Questions 52-54

 

The table shows a Series of Four fruit fly experiment breeding normal and vestigial wing flies. The flies in each cross could be either homozygous heterozygous for wing trait.

 

Parents

offspring

Cross

Female

Male

Normal wing

Vestigial wing

          1           

Normal Wing

Vestigial wing

95

0

          2           

Vestigial wing

Normal wing

105

0

          3           

Normal Wing

Normal Wing

76

23

          4           

Normal Wing

Vestigial wing

56

51

 

52.       The trait for vestigial wings is most likely

 

(A)       Autosomal dominant

(B)        Autosomal recessive

(C)        Sex linked dominant

(D)       Sex-linked recessive

(E)        It cannot be determined

 

53.       What is the most likely genotype of the female normal wing in cross 4?

 

(A)       Nn

(B)        NN

(C)        Nn

(D)       X-X

(E)        X-X-

 

54.       What is the most likely genotype of the male normal wing in cross 3?

 

(A)       NN

(B)        Nn

(C)        nn

(D)       X-X

(E)        X-X-

 

55.       Which is the true about the karyotype below?

 

 

 

 

 

 

 

Diagram

(A)       It shows a normal female.

(B)        It shows a normal male.

(C)        It shows a person who suffers from Down syndrome.

(D)       It shows person who suffers from a gene mutation.

(E)        It shows a person who suffers from a condition that result from nondisjunction.

 

Questions 56-58

 

Refer to this sketch of prokaryotic DNA as it commonly undergoes replication and transcription simultaneously

 

56.       If 1 is adenine, then A must be

 

(A)       Guanine

(B)        Cytosine

(C)        Thymine

(D)       Adenine

(E)        uracil

 

57.       If 1 is adenine, then A must be

 

(A)       Guanine

(B)        Cytosine

(C)        Thymine

(D)       Adenine

(E)        Uracil

 

58.       In what way would the ocess shown be different in a eukaryotic cell?

 

(A)       Eukaryotic cells & not carry out transcription.

(B)        Eukaryotic cells do not carry out replication.

(C)        Eukaryotic cells do not carry out both transcription and replication.

(D)       Eukaryotic cells carry our both processes, but they do not occur at the same time.

(E)        Eukaryotic cells carry oat both these processes in the Golgi body.

 

59.       A fungus infection affected nearly all-the oak trees in a particular that the coloration of the bark turned almost black. Scientists studying the diseased trees discovered that a moth population that inhabited the forest changed from being light brown to being almost black. Which of the following would best explain that color change of the moth population?

 

(A)       The moths. developed darker wings to blend in with the trees.

(B)        The. fungus infected the moths as well as the oak tree.

(C)        The almost black moths within the population were the only ones to survive once

(D)       The trees darkened because of the fungus infection.

(E)        The moths were the first to change color, which caused the trees to darken.

(F)         The fungus caused mutations to occur in the moths as well as in the oak trees

 

60.       According to scientific evidence, the age of Earth is closest to

 

(A)       400 years old

(B)        4,000 years old

(C)        400,000 years old

(D)       4,000,000 years old

(E)        4 billion years old

 

61.       All of the following are true of organisms classified in the domain Archaea EXPECT.

 

(A)       One example is E. coli, the organism that lives in the human gut

(B)        they can thrive in environment with very high temperature

(C)        they can thrive in environment with high salt concentrations

(D)       they have no intrnal membranes

(E)        their DNA an contain introns

 

62.       Factors that influence population density include which of the following?

 

I.       Predation

II.    Interspecies coopetition

III. Interspecies competition

 

(A)       I only

(B)        II only 

(C)        1 and III only

(D)       II and III only

(E)        I, II, and III

 

63.       The human population today can best described as

 

(A)       Declining

(B)        growing linearly

(C)        growing exponentially

(D)       at the carrying capacity

(E)        fluctuating seasonally

 

64.       All of the are true of K-strategists EXCEPT

 

(A)       Intensive parenting

(B)        reproduce only once or twice

(C)        example humans

(D)       large young

(E)        slow maturation

 

65.       Lamprey eels attach to the skin of certain tout and absorb nutrients from the body of the trout. Which symbols best represent this relationship?

 

(A)       (+/+)

(B)         (+/0)

(C)        (+/–)

(D)       (–/+)

(E)        (–/0)

 

Answers and Explanations

Question

Answer

Explanation

              1           

B

Prokaryotes (bacteria, monerans) have no membrane-bound organelles, so all reactions and processes occur in the cytoplasm. You should have been able to eliminate choice C, A and e because they did not describe locations.

              2           

D

When muscle cells run out of oxygen and switch to anaerobic metabolism (glycolysis only) to make ATP, the end product is lactic acid. Yeast can also switch to anaerobic metabolism; their end product is ethanol. You should have been able to eliminate choices A and B because they are not products.

              3           

B

Eukaryotes possess organelles and as such divide the location of their cellular processes among them. Glycolysis occurs in the cytoplasm, whereas the Krebs cycle and electron transport occur in the mitochondria. As in Question 1, you should have eliminated choices C, D and E.

              4           

E

Recombination occurs when the homologous chromosomes are paired and crossing over can take place. This occurs during prophase I of meiosis. Remember that recombination occurs during prophase, and this would help you eliminate choices A, B and D.

              5           

B

After prophase I, the homologous chromosomes remain paired and align at the center of the cell, on the “metaphase plate.” (The prefix meta means “middle.” Use this fact to help you elimate choices A, C and E.) During metaphase II, the individual, unpaired chromosomes align at the cell center.

              6           

A

During meiosis, the chromosomes remain replicated (i.e., remain as two jointed sister chromatids) for the entire first set of divisions. The whole point to the second set of meiotic divisions is to separate the sister chromatids. This takes place during and phase II.

              7           

D

Habituation involves becoming accustomed to certain stimuli that are not harmful or important. For example, if you walk down the hallway and a friend jumps out at you and you get scared, that is a normal reaction to a startling stimulus. However, if this happens every time you walk down the hallway, you get accustomed to it and no longer are startled. You have become habituated to the stimulus. Note that for Questions 7-9, you just had to know the basic definitions of these types of learning. Most of the classification type questions are like that.

              8           

B

Some animals do not have an instinctive sense for who their mother is and will bond with any object they are exposed to during a certain time period after their birth. The “imprints” on their minds, and thereafter, even if exposed to their real mother, they will still treat the object as Mom.

              9           

C

Conditioning involves the association of and response to one stimulus with a second, different stimulus. The best example is Ivan Pavlov’s dog. He rang a bell when he fed them, and the dogs salivated in response to the food. Soon, all he had to do was ring the bell, and the dogs would salivate, even in the absence of food.

            10         

A

Most digestion and absorption occur in the small intestine. A very small amount of digestion (starch only) takes place in the mouth, and a very small amount of digestion takes place in the stomach (acid hydrolysis of food and some protein digestion). As with Questions 7-9, Question 10-11 require the same type of knowledge - memorization of basic facts.

            11         

E

Saliva contains the enzyme amylase, which breaks down starch.

            12         

C

Cells in the stomach secrete hydrochloric acid, which keeps the pH of the stomach around 1-2, the other regions of the digestive tract maintain a fairly neutral pH.

            13         

A

Divergent evolution occurs when the same ancestral organism is placed into different environments and must then adapt to function in these different environments. Thus the same original structures evolve separately and “diverge” from one another. Examples of homologous structures are the arm of a man, the wing of a bat, and the flipper of a whale. All have the same basic bone structure but vastly different functions. The opposite of divergent evolution is convergent evolution, in which vastly different organisms are placed into the same environment and must adapt to perform similar functions with different structures. Convergent evolution produces analogous structures, examples of which are the wings of bats, the wings of butterflies. Speciation is often the result of divergent evolution, not the cause of it

            14         

C

The job of the blood is to carry oxygen from the lungs, where it is plentiful, to the tissues, where it is not. Thus hemoglobin should have a high affinity for oxygen in the lungs so it can bind oxygen (choices A, B and D could be eliminated) and a low oxygen affinity in the tissues (so it can release the oxygen where it is needed). The reverse is true for carbon dioxide. Hemoglobin has a high carbon dioxide affinity in the tissues and a low carbon dioxide affinity in the lungs.

            15         

D

In RNA, the base thymine (T) is replaced with uracil (U), so choice A can be immediately eliminated. Further, A will always pair with U, and G will always pair with C. The only choice that has the bases paired correctly is choice D.

            16         

B

Choices A, C, D and E all describe characteristics of the phylum arthropoda. A water vascular system is a characteristic of the phylum echinodermata, the “spiny skinned” animals such as sea stars and sea urchins. Their water vascular system ends in tube feet that play a role in locomotion and feeding. Don’t forget your LEAST/EXCEPT/NOT technique of circling the word “EXCEPT” and drawing a vertical line through the answer choices to help you remember to choose the incorrect statement.

            17         

E

The kidney’s primary role is to filter blood to remove wastes (statement I is true and choice D is eliminated), but it is also involved to a fair extent in blood pressure regulation (through renin and aldosterone, so II is true and choices A and C are eliminated) and in pH regulation through excretion of hydrogen ions, so III is true and choice B is eliminated).

            18         

D

If a pure-breeding long-tailed chicken (TT) mates with a pure-breeding short-tailed chicken (tt), all of their offspring (the F1 generation) will have the genotype Tt (and have long tails). Thus all of them, if mated with the correct genotype (Tt or tt), could produce offspring with short tails. Draw some quick Punnett squares to prove it to yourself.

            19         

B

Density-dependent factors are those that get more significant as the size of the population increases. Limited nutrients and water, toxic waste build-up, and predation are all issues that are of greater concern to a large population that to a small one. Only choice B, climate temperature, is not more worrisome to a large group than to a small one. It, will affect all populations equally, regardless of their size. Remember your LEAT/EXCEPT/NOT technique.

            20         

C

Two populations are considered separate species when they are so different from one another that they can no longer mate and produce viable offspring. Thus, organisms that can mate with each other must be of the same species.

            21         

E

Blood that is poor in oxygen returns from the body to the right side of the heart (I is true, so choices B and C are eliminated), then travels through the pulmonary artery (III is true, so choices A and D are eliminated) to get to the lungs, where it picks yup oxygen again. This oxygen-rich blood returns to the left side of the heart through the pulmonary vein (II is false) and is pumped back out to the body through the aorta.

            22         

B

The characteristics described are those of the phylum annelida, the best example of which is the earthworm. Mollusks have external shells (snails), echinoderms and arthropods have exoskeletons (sea stars, crustaceans, insects), and chordates have endoskeletons and, in any case, are not worms.

            23         

A

The light reactions of photosynthesis convert solar energy to usable energy in the form of ATP (choices C and E are eliminated) and NADPH (a reduced electron carrier). The ATP and NADPH (i.e. energy) produced during these reactions are used later during the Calvin cycle to fix carbon dioxide into carbohydrates, like glucose. Because glucose is a product of the light-independent reactions, choice B could be eliminated. Remember that NADPH belongs with photosynthesis to eliminate choice D.

            24         

C

When the concentration of substrate far exceed the concentration of enzyme (remember, the question states that enzyme concentration is assumed to be constant), all the enzyme active sites are saturated with substrate, and the product is being formed at its maximum rate. The only way to increase product formation at this point is to increase the concentration of the enzyme. Note that enzymes should not be used up in the course of the reaction (A is wrong). Furthermore, product formation is still occurring, just at a stable rate (B and D are wrong). There is no reason to assume an inhibitor has been added; the rate of product formation remains constant.

            25         

D

Berries are plant products (i.e. primary producers), thus any organism that eats berries is a primary consumer, on an herbivore (I is true, choices B, C and E can be eliminated). Notice at this point that the only remaining choices (A and D) do not contain option III, therefore, option III is false. Secondary consumers, carnivores and omnivores (e.g. birds) eat primary consumers (e.g. bugs), thus II is also true, and choice A can be eliminated. Terriary consumers are carnivores (e.g. cats) that eat other carnivores (e.g. birds, secondary consumers). III is false, as we saw earlier.

            26         

B

Carbohydrate have the general molecular formula C6H2nOn, as in glucose, which is C6H12O6. The only formula that fits this rule is choice B.

            27         

C

A change in a population that occurs over a long period of time is evolution. This alone is a good tip-off that choice C, the only choice that mentions evolution, is correct. Speciation has not occurred, only a change in the characteristic of the birds, thus choices A and D can be eliminated. Any change in the fitness of the insects would change the characteristics of the insect population, not the bird population (B is wrong), and random mutation would not produce a specific, directed effect (E is wrong). Birds with large beaks had greater fitness because they could more easily obtain food, thus they had an advantage over birds with smaller beaks, which dies out as tie passed.

            28         

E

The other choices do not describe substrate binding sites on an enzyme.

            29         

D

Break this question down one piece at a time. First, the question states that there is a high sodium concentration outside the cell. This means sodium wants to move into the cell (where concentration is lower). Choices A and C can be eliminated because they state that sodium would move out of the cell. Active transport requires ATP, and because there is no ATP involved, choice E can be eliminated. Last, because sodium moves across the membrane with the help of a channel, it is moving by facilitated diffusion (choice B is eliminated).

            30         

E

Decomposers take organic material and break it down into its individual compounds, thus returning these compounds back to the earth. The other processes listed are carried out by other organisms: nitrogen fixing bacteria (choice A), heterotrophs and autotrophs (choice B), and other soil bacteria (choice C and D)

            31         

B

The endocrine system is a body control system, but it is NOT rapid. The fastest hormone in the body is adrenaline, and even that takes a few seconds, compared the nervous system’s milliseconds. Most hormones operate in the minutes to hours range. The other choices regarding the endocrine system are all true. Remember your LEAST/EXCEPT/NOT technique!

 

            32         

B

This symbiotic relationship describes commensalism. In mutualism both partners benefit, in parasitism and predator prey relationships one partner benefits while the other is harmed, and symbiosis is just a general term used to describe close living arrangements.

 

            33         

D

Relationships that are directly proportional have linear graphs with a positive slope.

            34         

B

Male haploid cells (pollen grains or microspores are produced on the anther (#2 in the diagram), which is at the tip of the filament (#3 in the diagram).

            35         

A

Pollen grains stick to the stigma (#1 in the diagram), which is supported by the style (#4 in diagram).

            36         

E

The pollen fertilizes the ovule (female haploid cells, or megaspores, # 6 in the diagram); once fertilized, the ovary (#8 in the diagram) develops into a fruit.

            37         

C

The prefix photo refers to light; because the light is growing toward light we can eliminate choices A, D and E. “Positive” means growing toward, so choice B can be eliminated.

            38         

A

The prefix geo refers to the earth, or soil’ thus we can eliminate choices C, D and E. because the plant is growing away from the earth, this is a negative tropism and we can eliminate choice B.

            39         

D

A surge in LH is what causes ovulation and is measured in the ovulation prediction kits. Estrogen and progesterone affect the uterus, not the ovary, and FSH causes development of a follicle (A, B and C are wrong). Testosterone is a male hormone (E is wrong).

            40         

BH

Because we know hormone X is peaking at ovulation time, a quick look at the graph shows hormone X peaking at about Day 14 of the cycle.

            41         

A

The rise in hormone Y occurs after ovulation (choice E is wrong) and coincides with formation of the corpus luteum (choices B and D are wrong). The primary hormone secreted by the corpus luteum is progesterone.

            42         

E

Rapid cell division after fertilization is known as cleavage. Blastulation is the formation of a hollow ball of cells (A is wrong), gastrulation is formation of the three primary germ layers (B is wrong), neurulation is development of the nervous system (C is wrong), and implantation is when the morula (solid ball of cells) burrows into the uterine lining (D is wrong).

            43         

C

You should remember the prefixes anto, meso, and endo for the primary germ layers and therefore eliminate choices D and E right away. The ectoderm forms the skin, hair, nails, mouth lining and nervous system. The mesoderm forms muscle, bone, blood vessels, and organs (B is wrong). The endoderm forms inner linings and glands (A is wrong).

            44         

B

The development of a thriving ecosystem from a barren area is known as succession. Note the evolution usually has a much longer time frame than succession.

            45         

B

The climax community is the final, stable community in secession. The key word here is “stable.” That should tip you off that this is the end of the process, or the “climax.”

            46         

D

The first organisms to colonize a barren area are known as the pioneer organisms.

            47         

A

Diuretics help eliminate water (i.e., increase urine production) from the body. From the data tables, the only substance that increases urine production significantly is caffeine. Don’t forget the I, II, III technique here; even just knowing that option I is true allows you to eliminate two (choices B and D) of the five choices.

            48         

A

Again, from the data tables, there is a directly proportional (i.e., linear) relationship between the amount of caffeine ingested and the volume of urine produced. As caffeine ingested and the volume of urine produced. As caffeine consumption increases, so des urine volume. The only graph that shows this relationship is choice A.

            49         

C

Because the caffeine and the sodium chloride were dissolved in water, plain, water was consumed as a control, to make sure the effects seen were due to the added substances and not the water. Questions about experimental controls come up fairly frequently on the SAT Biology E/M. Subject Test; make sure you know the definition for a control and how to spot in the experiment.

            50         

C

From Table 2, an increase in sodium chloride of 0.9 g results in a decrease in urine volume of approximately 40 ml. when 3.6 g sodium chloride are ingested, 82 ml urine is produced; thus if 4.5 g sodium chloride were to be ingested, the expected urine volume would be 40 ml less, approximately 40 ml.

            51         

B

As soon as you see “hemophilia,” you should be thinking “X-linked disorder.” Then use the technique for avoiding the temptation trap, which is particularly dangerous here, because the passage and the questions are confusing, and it’s very tempting to just guess blindly. Resist! Take the paragraph apart piece by piece, sentence by sentence. Write out genotypes as you read through and construct Punnett squares to help you see probability. Out of this family, the only members that express this condition are males. This is a tip-off for X-linked disorders, which are more common in males because they have only a single X chromosome. (In any case, you should remember the two most common X-linked disorders; hemophilia and color blindness). John’s genotype is YXh. He passed his Y chromosome to Mark and Mike; they also received a normal X from Jane, thus they do not have hemophilia, nor can they pass it on to their kids. Molly and Mary received Xh from John but also received a normal X from Janem thus they are carriers of hemophilia but do not display its symptoms.

            52         

A

Because Mike does not carry the gene for hemophilia (see above), he cannot pass it on to his children, and they in turn cannot pass it on to their children.

            53         

D

Mark and Mike does not carry the gene for hemophilia (see solution to 51 above), thus we can eliminate choices A, B, and E. Jane is normal, so choice C is eliminated as well.

            54         

C

From Table 1, substance B caused on increase in serum calcium levels, which is the effect that insulin has on the body.

            55         

E

Again, from Table 1, substance A caused on increase in serum calcium levels, which is the effect that insulin has on the body.

            56         

B

Substance D causes an increase in serum sodium, which is the effect aldosterone has on the body. Aldosterone is released when blood pressure is low, because excess sodium will have the effect of causing water retention, which will increase blood volume, which will increase blood volume, which will increase blood volume, which will increase blood pressure. (Note: Even if you did not know this, you should have been able to eliminate the other choices.)

            57         

E

The change in serum sodium after injection of Substances B is insignificant. All other choices cause significant change from the baseline values of the variable being measured. Don’t forget the LEAST/EXCEPT/NOT technique.

            58         

C

Cell Type A has no nucleus. The only organisms that do not have nuclei are bacteria (kingdom Monera).

            59         

E

Cell Type C has a nucleus, a cell wall, and chloroplasts and therefore most likely comes from a plant. Equations II and II are the equations for photosynthesis and would occur in plants (choices A, B, and C are eliminated), and equation I is the equation for cellular respiration, which also occurs in plants (choice D is eliminated).

            60         

D

This is a great question to do some answer predicting on. At Time I the oxygen was removed from the cultures and cell Type C died. Clearly it is an obligate aerobe. Thus we can eliminate choices A, B, and C. Because cell Type B was growing well in the presence of oxygen, it cannot be an obligate anaerobe, thus choice E is eliminated. Cell Type B must be a facultative anaerobe, suing oxygen when kit is available and fermenting when oxygen is not available. The decrease in growth of cell Type B after Time I is most likely because energy is produced during fermentation than during aerobic metabolism.

            61         

E

These are the characteristics of desert.

            62         

B

These are the characteristics of taiga.

            63         

C

These are the characteristics of tropical rain forest.

            64         

A

These are the characteristics of tundra.

            65         

D

Flowering plants are angiosperms. Gymnosperms are confiders (naked seed plants; C is wrong), bryophytes are mosses (A is wrong), and tracheophytes are non-seed producing plants (ferns; B is wrong). “Endosperm” is not a classification for plants.

            66         

A

If an organism’s environment remains absolutely constant, and that organism still exhibits regular rhythms of activity there must be some internal “clock” that keeps it on schedule (C and E are wrong). Roosters vary the time of their crow as the sun varies the time it rises (B is wrong). ‘The magnetic field has nothing to do with internal clocks (D is wrong).

            67         

D

Remember: “King Philip came Over From Germany – so?” or make up you own!

            68         

A

Rattlesnakes are clearly heterotrophs (only photosynthetic organisms are autotrophs), so we can eliminate choices B and C. Rattlesnakes are carnivores, not producers (D is wrong) or primary consumers (herbivores, so E is wrong).

            69         

E

Remember your LEAST/EXCEPT/NOT technique. There are four features present in al chordates – dorsal nerve cords (choice A), notochords (choice B), gill slits (choice C), and postnatal tails (choice D). Note that some of these features may be found only in embryonic or larval stages. The “wrong” answer is choice E _ note all chordates (for example, sea squirts and lancelets) have a bony endoskeleton.

            70         

D

The question asks for the average beak length in cm, but the graph gives it in mm. Average beak length is 30 mm. 10 mm = 1 cm; therefore, 30 mm =  cm. read the questions carefully!

            71         

B

Clearly the birds with 30 mm beaks were not surviving too well. There is no reason to assume they flew to another island; remember, they are on a remote, isolated island. There may not be another island near enough to fly to (Asis wrong). If predators consumed birds with 20 mm or 40 mm beaks they would not be the prevalent populations in Figure 2 (C and D are wrong), and if birds with 30 m beaks were selected for, the population would  not have been divided (E is wrong).

            72         

B

The defining characteristic for speciation is an inability to interbreed.

            73         

E

Just because we have some information about how the population change in the last 200 years, it doesn’t tell us how it may change in the next 200 years. It would depend on how the environment changed during that time period.

            74         

D

As the acidity increases (pH goes down), the average mass of the fish decreases. How-ever, it does not decrease linearly; rather, it says constant for a while, then gradually drops off, then rapidly drops off as acidity becomes severe. The best representation of this is choice D.

            75         

D

The plant benefits by easier availability of water and phosphorus, and the fungi benefit by receiving amino acids and sugars. Another term for this type of relationship is mutualism.

            76         

E

pH 7.0 is neutral, thus neither the plant nor the fungi would be harmed.

            77         

B

The best way to prevent damage from acid rain would be to prevent its formation by reducing the burning of the fossil fuels that cause it. There is no guarantee that bigger fish will resist the acidity any better than smaller fish (A is wrong), supplying plants with sugars and amino acids will not help them overcome the effects of acid soil (D is wrong), and, even if alkalines will neutralize acid, they might be just as harmful to the environment (E is wrong)!

            78         

C

Fungi are euakryotes (A and E are eliminated), and they are not photosynthetic (B and D are eliminated).

            79         

B

Clearly P. Aurelia can compete better and get more food that P. caudate; thus it will grow while P. caudate is competed to extinction. Choice A is highly unlikely because the good source the paramecia prefer is bacteria, not each other. This is not a symbiotic relationship but a competitive one (C and D are eliminated), and the data contradict choice E.

            80         

D

Paramecia are single-celled eukaryotes, members of kingdom Protista.

            81         

B

RNA bases do not include thymine; they are adenine, guanine, cytosine, and uracil. All other statements about RNA are correct. Remember the LEAST/EXCEPT/NOT technique!

            82         

A

Ribosomes synthesize protein (B is wrong), mitochondria function in respiration (C is wrong), vacuoles help expel waste (D is wrong), and lysosomes function in digestion (E is wrong).

            83         

D

Choices A and E are prokaryotic and can be eliminated. Chordates have no cell walls (B is wrong), and plants have chloroplasts (C is wrong).

            84         

A

The defining characteristic for speciation is an inability to interbreed. Choices B, C, D, and E could all ultimately produce two different populations that lack the ability to mate. Choice A would not lead to an inability to mate. Remember this is a LEAST/EXCEPT/NOT questions.

            85         

E

A retrovirus has an RNA genome, so its polymerase must be able to read RNA (DNA-dependent choices C and D can be eliminated). Furthermore, retroviruses go through the lysogenic life cycle, and so must insert their genome into their host’s genome. Because all other organisms have a DNA genome, a DNA copy of the viral (RNA) genome must be synthesized. A DNA polymerase is needed (choices A and B can be eliminated). Note that the host’s RNA polymerase is DNA dependent, the same answer as choice C.

            86         

B

The members that have the most in common with one another are the members near the bottom of the hierarchy. Of the choices given, genus is the closest to the bottom of the hierarchy.

            87         

D

Anyone who has produced offspring has demonstrated their fitness. Regardless of how healthy a child is, he has not yet produced offspring to prove his fitness. Use the LEAST/EXCEPT/NOT technique.

            88         

C

The only plate that Colony 3 cannnot grow on is Plate C, which lacks proline. Thus colony 3 requires proline to row and is a proline auxotroph (pro). This eliminates choices A, B, and D. Choice E is incorrect because Colony 3 does not require arginine or leucine to grow; it can grow just fine in the absence of these amino acids, as is indicated on plates A and B.

            89         

D

Colony 1 can grow on any of the plates, thus it does not require any additional amino acids. Auxotrophs require additional supplements to their growth media.

            90         

B

Because these are bacterial colonies, they would not have any membrane-bound organelles, and thus no nuclei (choices A, C, and E can be eliminated) or mitochondria (choie D can be eliminated). Bacteria do have ribosomes to synthesie proteins.

            91         

A

It really helps to predict an answer BEFORE you look at the answer choices. Sometimes looking at the choices first can confuse your thinking and lead you to a trap, but if you have an idea of the correct answer before you look at the choices, you will be less tempted. Colony 4 cannot grow in the absence of arginine as is evidenced by Plate B. thus, because the liquid medium does not contain arginine, no bacterial growth would be observed.

            92         

B

Again, try to predict an answer first. Clear spots lawns of bacteria are due to infection by viruses that cause lysis of the bacteria. Even if this was not obvious to you, you should have been able to eliminate the other choices. There is no reason to assume Colony 2 would prey on Colony 1 (A is wrong); strong acid would lyse and destroy the Bacteria immediately, not after 24 hours (C is wrong); bacteria are not delicate, they can grow just about anywhere, under any conditions (D is wrong); and there is no data to support fact that threonine may be toxic to the bacteria or that the “unknown organism” was producing it.

            93         

D

Structures with similar functions but different underlying structures are the result of vastly different organisms being placed into similar environments and having to adapt to the same stresses with different starting materials. These are termed “analogous structures” and are the result of convergent evolution. (See also Questions # 13).

            94         

B

Because the percentage of black moths is increasing, they must be selected for. This eliminates C and E. because the percentage of white moths is decreasing, they must be selected against, eliminating choice A. choice D is wrong because white moths would not blend better against dark tree bark.

            95         

D

The original parent had white bark. The change in bark color is the result of an accumulation of soot on the tree. This is an acquired characteristic and would not be passed on to offspring. Seedlings that grew far from the plant would not be exposed to soot in the air and would not experience discoloration of their bark.

            96         

C

The reason the percentage of black moths increased was because they were no longer visible against the now darkened bark of the trees. Because the white moths were more easily seen by the birds, their numbers declined. However, because bats rely on sonar to locate prey instead of vision, darker coloring would not give the moths any advantage, and the population percentages would stay at the point they were at when the birds were replaced by bats, a fifty-fifty split.

            97         

C

Sucrose cannot cross the dialysis membrane, so it cannot cause any effect on the mass of the tubes. This eliminates choices A, B, D, and E.

            98         

D

Because movement across the membrane relies strictly on concentration gradients, the fact that there is no gradient in Tube 1 would prevent the movement of water into or out of the tube thus there would be no change in miss.

            99         

B

The gradient in Tube 3 is much larger than the gradient in Tube 2, thus water would be expected to enter more rapidly. This is confirmed by the data in Table 1. A linear graph should show two lines with positive slopes, and the slope of Tube 3’s line should be greater than the lope of Tube 2’s line.

          100       

C

The fact that the cell does not swell or shrivel in 0.9% NaCl implies that there is no concentration gradient. A cell in a 20% NaCl solution would experience similar stresses to a dialysis tube filled with water sitting in a beaker filled with a more concentrated solution, such as Tube 4. The data indicate that Tube 4 lost mass, thus water exited the tube, and the same would happen to the red blood cell.

 

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