BIOLOGY

SECTION I
Time- 1 hour and 30 minutes

Directions: Each of the questions or incomplete statements below is followed by five suggested answers or
completions. Select the one that is best in each case and then fill in the corresponding oval on the answer sheet.

1. One of the most profound differences between 3. As part of an experiment to investigate the
animal and plant cells is that effects of cadmium on the hearts and livers of
rats, the experimental group of rats receiving 5
(A) animal cells alone have one or more parts per million of cadmium in their drinking
vacuoles water each day. The control rats are given water
(B) animal cells alone have a nucleolus from which all cadmium has been removed. For
(C) animal cells alone have their chromatin the experiment to be valid all of the following
attached to the spindle fibers during mitosis. conditions are necessary EXCEPT:
(D) Plant cells alone have rough endoplasmic
reticulum. (A) The rats should eat the same kinds and
(E) Plant cells alone have relatively thick rigid amount of food.
cell walls. (B) The experimental and control rats should
be the same age and have the same body
2. The introduction of antibiotics such as penicillin weight.
several years ago was immediately effective in (C) The rats should be housed under the same
combating infections caused by Staphylococcus. conditions of temperature and humidity
In 1958, however, there were several outbreaks (D) The control rats should receive water
of staphylococcal infections. People with the fortified with other minerals to make up for
infections did not respond to treatment with any the cadmium loss.
of the antibiotics and there was a large number (E) The rats should be members of the same
of deaths. The best explanation for this species.
situation is that
4. Which of the following is LEAST likely to be a
(A) the bacteria reproduced in hosts that were factor in the movement of water through a
not contaminated with antibiotics terrestrial plain?
(B) the bacteria from other hosts such as birds,
cats, and dogs migrated into human hosts (A) the cohesion of water
(C) the bacteria exposed to nonlethal doses of (B) the influence of gibberllin on cell
antibiotics quickly learned to avoid them expansion
(D) each generation of bacteria acquired the (C) capillary action
ability to use antibiotics as nutrients (D) root pressure
(E) antibiotic-resistant bacteria survived and (E) the evaporation of water from the leaves
multiplied, and these were the forms
causing the infections 5. The external similarity of dolphins to sharks is
an example of

(A) convergent evolution

(B) divergent evolution
(C) behavioral isolation
(D) geographical isolation
(E) adaptive radiation
6. Which of the following macromolecules is
primarily responsible for the insolubility of cell
membranes in water?

(A) Starch
(B) Cellulose 10. In the series of enzyme reactions above, product
(C) Protein Z is able to copy the active site of enzyme E2.
(D) Phospholipid Product Z can therefore first inhibit the
(E) Glycogen production of
(A) W
7. Competitive exclusion is most likely to occur (B) E1
between two (C) X
(D) E2
(A) closely related species occupying different (E) Y
niches
(B) closely relates species occupying the same 11. A scientist measured the water content of leaves
niche from two different groups of oak trees on three
(C) related species occupying different habitats different summer days. One group of leaves,
(D) unrelated species occupying different the T group, came from trees that had been
niches defoliated by gypsy moths the previous year.
(E) populations of the same species The other leaves, the C group, came from trees
which had not been defoliated. The results, in
8. Water-soluble vitamins in human nutrition serve milliliters of water per gram of dry weight, are
primarily as shown in the table below.

(A) a source of calories June 10 June 30 July 28

(B) repair agents for damaged DNA T Group 26.8 20.4 12.7
(C) shields that absorb cosmic radiation C Group 32.5 28.7 22.7
(D) coenzymes for specific enzymes
(E) antioxidants that protect membrane lipids All of the following are valid interpretations of
these data EXCEPT:
9. Which of the following sequences describes the
passage of a nerve impulse through a simple (A) C leaves typically contain more water than
reflex arc in humans? do T leaves
(B) Both C and T leaves show declines in water
(A) Receptor, sensory neuron, motor neuron, content as the summer goes on.
association neuron, effector (C) T leaves show greater declines in water
(B) Receptor, motor neuron, association content than do C leaves.
neuron, sensory neuron, effector (D) Defoliation by gypsy moths has no effect
(C) Receptor, sensory neuron, association on the water content of next year’s leaves.
neuron, motor neuron, effector (E) Differences in the water content between C
(D) Effector, motor neuron, association neuron, and T leaves grow greater as the summer
sensory neuron, receptor goes on
(E) Receptor, association neuron, sensory
neuron, motor neuron, effector
12. In cells, which of the following can function to 16. A human genetic defect that affects the ability to
give shape, enable movement, and anchor metabolize a particular amino acid is
organelles?
(A) Vacuoles filled with water and surrounded (A) phenylketonuria
by a single membrane (B) hemophilia
(B) Ribosomes, peroxisomes, and lysosomes (C) sickle cell anemia
(C) Microtubules, microfilaments, intermediate (D) Down’s syndrome
fibers, and microtrabeculae (E) Turner’s syndrome
(D) The interconnected networks of the
endoplasmic reticulum /\ <|---- Humans
(E) Golgi apparatus and associated vesicles in / \ <|---- Fish
the cytoplasm / \ <| ---- Minnows
/ \ <|---- Copepods
13. If red hair, blue eyes. and freckles were / \ <|---- Algae
consistently inherited together, the best
explanation would be that 17. In the food pyramid above, which of the
following organisms are herbivores?
(A) these traits are recessive characteristics
(B) both parents have red hair, blue eyes, and (A) Humans
freckles (B) Fish
(C) the genes for these traits are linked on the (C) Minnows
same chromosome (D) Copepods
(D) gene duplications have occurred (E) Algae
(E) these traits are dominant to others
18. All of the following affect the amount of oxygen
14. Vertebrates became truly terrestrial with the carried by the blood EXCEPT
development of the amniotic egg in
(A) the- pH of the blood
(A) fish (B) the percentage of carbon dioxide in the
(B) amphibians plasma
(C) reptiles (C) the percentage of oxygen in the air
(D) birds (D) a decrease in the number of red blood cells
(E) mammals in the plasma
(E) a decrease in the number of white blood
15. If the larvae of a particular species of mosquito cells in the plasma
are to survive to the adult stage, the eggs must
be laid in the trapped pool of water of the 19. Species that utilize the same source of nutrition
northern pitcher plant. The mosquito larvae within a food web can best be described as
provide no apparent benefit or harm to the
pitcher plant. This type of interaction is an (A) providing double links in a food chain
example of (B) being homeothermic relative to energy flow
(C) occupying the same trophic level
(A) commensalism (D) being secondary consumers within a
(B) predation complex food web being autotrophs.
(C) parasitism (E) heterotrophs or omnivores
(D) mutualism
(E) competition
20. A species of malaria-carrying mosquito lives in 24. The function of the acrosome of the sperm is
a forest in which two species of monkeys. A and to
B, coexist. Species A is immune to malaria but
species B is not. The malaria-carrying mosquito (A) orient the pattern of the microtubules for
is the chief food for a particular kind of bird in motility
the forest. If all of these birds are eliminated (B) carry genetic information
suddenly by hunters, which of the following (C) carry the enzymes that facilitate
would be the immediate observable fertilization
consequence? (D) provide energy for movement
(E) regulate protein synthesis in the sperm
(A) Increased mortality in monkey species A
(B) Increased mortality in monkey species B 25. The “all-or-none” law, as it applies to
(C) Increased mortality in the malaria-carrying impulse transmission, states which of the
mosquitoes following?
(D) Emergence of malaria-resistant strains in
monkey species B (A) If a stimulus is applied, either all
(E) Emergence of malaria-sensitive strains in neurons fire or none do.
monkey species A (B) A stimulus causes either all the sodium
to teak into the neuronal membrane or
21. Monogamy is usually more common among none of it.
birds and mammals whose young are (C) Either all neurons develop an action
potential upon stimulation or none do.
(A) born helpless and in need of much parental (D) If a stimulus is at or above the threshold,
care an action potential will be generated: if
(B) precocial and able to care for themselves not, then the neuron will not fire.
(C) hatched from among thousands of eggs (E) Either all neurons will be repolarized or
(D) nourished on milk none will be.
(E) carried by the Female from conception to
birth 26. From the graph above, it can be correctly
concluded that
22. Root hairs are extensions of which of the (A) hemoglobin has an affinity for oxygen
following kinds of cells? that varies with the carbon dioxide
concentration
(A) Cortical (B) myoglobin and hemoglobin have
(B) Xylem distinctly different molecular weights
(C) Phloem (C) hemoglobin becomes saturated with
(D) Epidermal oxygen at lower partial pressures than
(E) Meristematic does myoglobin
(D) myoglobin has a greater affinity for
23. Mitosis in flowering plants is similar to mitosis oxygen at lower partial pressures than
in animals in that in both does hemoglobin
(E) hemoglobin and myoglobin regulate the
(A) a cell plate forms partial pressures of oxygen in the blood
(B) synapsis of homologous chromosomes
occurs 27. All of the following are deuterostomes
(C) large centrioles attach to the spindle fibers EXCEPT
(D) each daughter cell has half the number of
chromosomes found in each parent cell (A) mollusks
(E) centromeres uncouple and chromosomes (B) reptiles
move apart (C) amphibians
(D) echinoderms
(E) mammals
28. A new species of organism has evolved 31. Which of the following statements
when concerning respiration is correct?

(A) the climate of a population’s area has (A) Aerobic respiration is probably more
changed greatly ancient in an evolutionary sense than is
(B) a population can no longer interbreed anaerobic respiration.
under natural conditions with other (B) When oxygen is absent, fermentation
closely related organisms proceeds without the participation of
(C) variation has occurred within the species enzymes.
due to mutations (C) Each NADH + H ~ generated in the
(D) a population has been recently isolated Krebs cycle contains sufficient energy
from the rest of the species by a for the production of 3 ATP molecules.
geographic barrier (D) Unlike pyruvic acid, fatty acids break up
(E) selection pressures have produced a into 3-carbon units during respiration.
group of demes (E) In one turn of the citric acid cycle, 8
molecules of CO2 are formed.
29. Carbon dioxide is passed into a solution of
bromthmol blue indicator until the acid 32. Which of the following statements about a
solution turns yellow. A sprig of elodea is typical aquatic angiosperm is correct?
then placed into this yellow solution. After a
few hours in the sunlight, the yellow (A) It forms spines.
solution turns blue. The purpose of this (B) It has fleshy leaves for water
experiment is to show that storage.
(C) It has extensive taproot systems.
(A) oxygen is given off during (D) It has stomata in sunken cavities.
photosynthesis (E) It has stomata on the upper leaf
(B) carbon dioxide is used during photo- surfaces.
synthesis
(C) carbon dioxide is given off as a 33. Girdling of a tree by completely removing a
by-product of photosynthesis ring of bark most directly affects the process
(D) bromthymol blue changes to of
bromthymol yellow under acid
conditions (A) translocation
(E) chlorophyli acting as a photocatalyst is (B) transpiration
necessary for photosynthesis (C) photosynthesis
(D) countercurrent exchange
30. In traveling from a forest ecosystem to a (E) cellular respiration
grassland, one notes that the trees gradually
give way to prairie grasses. The critical 34. All of the following are examples of the
factor governing this shift is usually the benefits of bacteria to humans EXCEPT

(A) length of the growing season (A) vitamin manufacture in the large
(B) annual mean temperature intestine
(C) availability of carbon dioxide (B) bacterial action in the making of
(D) availability of water silage
(E) availability of oxygen (C) bacterial action in the making of
exotoxins
(D) the production of drugs such as
streptomycin
(E) the production of acids that flavor
cheese
35. During development. individual cells of the 39. Human identical twins develop when
same organism begin to produce different
proteins because (A) two identical eggs are fertilized by two
different sperm
(A) the cells have different numbers of (B) a single egg is fertilized by two sperm
chromosomes (C) two different eggs are fertilized by two
(B) not all cells can synthesize proteins different sperm
(C) specific genes are activated in the cells (D) the embryo splits and each portion con-
(D) the cells have different kinds and tinues to develop
amounts of DNA (E) a diploid egg is fertilized by a diploid
(E) genes are permanently lost as somatic ovum
cells differentiate
Grass—>Cricket—>Prairie chicken
36. When a person exercises strenuously, all of —>Coyote—>Vulture
the following occur EXCEPT: 40. In which organism in the food chain above
(A) Glucose decreases. would the biological magnification of DDT
(B) ADP increases. concentration be most obvious?
(C) Lactic acid increases.
(D) Glycogen increases. (A) Grass
(E) CO increases. (B) Cricket
(C) Prairie chicken
37. Actinomycin D is an antibiotic drug that (D) Coyote
inhibits protein synthesis by blocking (E) Vulture
transcription. In some cells, the application
of the drug does not affect the synthesis of 41. In a population at equilibrium, thousands of
certain proteins. Which of the following best eggs and hundreds of tadpoles are produced
explains such an occurrence? by a single pair of frogs. About how many
offspring will live to maturity and
(A) Not all proteins need tRNA molecules reproduce?
for their synthesis.
(B) The proteins that are made are using (A) 0
mRNA synthesized before application of (B) 2
the drug. (C) 10-20
(C) nuclear proteins do not require the (D) 100
cytoplasmic machinery of ribosomes. (E) More than 100
(D) DNA transcription is not necessary for
protein synthesis. 42. According to the Jacob-Monod model of the
(E) Protein synthesis is blocked in the lac operon, the regulator gene does which of
cytoplasm at the ribosome level. the following?

38. All of the following statements about a (A) Specifies the amino acid sequence of the
chloroplast and a mitochondrion are true enzyme.
EXCEPT: (B) Controls the activity of histones.
(C) Determines whether promoter genes will
(A) Both use proton gradients for energy be translated.
production. (D) Directs the synthesis of a repressor
(B) Both capture light energy. protein.
(C) Both contain DNA. (E) Produces corepressor substances.
(D) Both are bounded by two unit
membranes.
(E) Both synthesize ATP.
43. The use of the isotope phosphate as a tracer 47. Hormones stimulate the uterine lining to
element in the study of invasion and lysis of thicken in preparation for
bacteria by bacteriophage viruses has shown
that (A) ovulation
(B) fertilization
(A) ATP from bacteriophages is identical to (C) lactation
ATP found in eukaryotic cells (D) menstruation
(B) bacteriophage protein enters the bacteria (E) implantation
through the cell wall
(C) bacteriophage nucleic acids enter 48. Flowering in plants such as tobacco and
bacteria prior to lysis cocklebur and the germination of certain
(D) 32p accelerates the lytic effect of bacter- lettuce seeds are induced primarily by
iophage infection
(E) 32p in an inactive form enters the (A) photoperiodism
bacterial genome as part of a plasmid (B) temperature
(C) negative feedback
44. A study of the metabolic rate in a terrestrial (D) circadian rhythms
community shows that the energy released (E) lunar phases
by respiration exceeds the energy captured
in photosynthesis. Which of the following 49. Prokaryotes differ from eukaryotes in that
situations is occurring? only the prokaryotes contain

(A) Community biomass is decreasing. (A) mitochondria in which glucose is

(B) Community biomass is increasing. oxidized
(C) A climax community has been reached. (B) DNA that is not bound to histone protein
(D) The first law of thermodynamics is not (C) chromosomes enclosed within a nuclear
in effect. envelope
(E) The second law of thermodynamics is (D) photosynthetic pigments in plastids
not in effect. (E) plasma membranes surrounding the
cytoplasm
45. Which of the following led most directly to
a decrease in the amount of ultraviolet 50. Eutrophication in lakes is frequently the
radiation reaching the Earth’s surface? direct result of

(A) Fermentation (A) nutrient enrichment

(B) Heterotrophs (B) industrial poisons
(C) Anaerobic respiration (C) a diminished supply of nitrates
(D) Photosynthesis (D) an increase in predators
(E) A reducing atmosphere (E) decreased light penetration

46. All of the following conditions would result

in a change in the frequency of a specific
allele in a population EXCEPT

(A) selection against the recessive phenotype

(B) selection against the dominant
phenotype
(C) genetic drift
(D) random mating in a large population
(E) mutation of the dominant allele to the
recessive allele
51. Many birds, insects, and terrestrial reptiles Question 57 & 59 refer to the diagram below
excrete nitrogenous wastes in the form of uric
acid that

(A) is synthesized in the kidneys from

ammonia and CO2
(B) forms crystals that are relatively
insoluble and nontoxic
(C) readily decomposes on exposure to air
(D) is readily excreted through feathers and
scales
(E) can be recycled and utilized as an
additional energy source

57. The structure above could be any of the

following EXCEPT
59.So-called high-energy bonds include the bonds
(A) nucleotide at
(B) monomer used as a component of a
polypeptide (A) A and B only
(C) reactant used in the synthesis of nucleic (B) B and C only
acids (C) C and D only
(D) molecule of adenosine triphosphate (D) D and E only
(E) molecule that is the energy source for (E) B, C, D, and E
most anabolic activity in cells

58. During muscle contraction the molecule in the

diagram is converted into

(A) cyclic AMP + phosphate

(B) pyruvic acid + CO2
(C) glycogen
(D) ADP + phosphate
(E) acetyl-CoA + CO2
Directions: Each group of questions below consists of five lettered headings followed by a list of numbered
phrases or sentences. For each numbered phrase or sentence, select the one heading that is most closely related
to it and fill in the corresponding oval on the answer sheet. Each heading may be used once, more than once, or
not at all in each group.

Questions 65-67 Questions 70-73 refer to the graph below that shows
the changes in population size over time.
(A) Glucagon
(B) Insulin
(C) Epinephrine
(D) Glucocorticoids
(E) Thyroxine

65. A polypeptide that lowers the level of blood

glucose by increasing the permeability of cell
membranes to glucose

66. An iodinated amino acid that increases the

oxygen consumption and metabolic rate of
nearly all cells

67. A substance produced by the alpha cells of the

pancreatic islets and involved in the increase of
glycogenolysis in the liver 70.A mature, well-established population in
favorable conditions

Questions 68-69 71. The carrying capacity of the environment

(A) Axon 72. A population in unfavorable conditions

(B) Dendrite
(C) Glial cell 73.The exponential growth phase of a new
(D) Synapse population
(E) Interneuron

68.Conducts impulses away from the cell body of a

neuron

69.Forms the myelin sheath

Questions 74-75 Questions 84-85 refer to a cell whose normal
diploid number is 32.
(A) 1/ 16
(B) 1/4 (F) 8
(C) 1/2 (G) 16
(D) 9/16 (H) 32
(E) 1 (I) 64
(J) 128
Galactosemia is a simple, inherited, autosomal
recessive trait. A normal couple has a child affected 84. What would be the chromatid number of a cell
with galactosemia. For each of the following situa- in late Prophase I of meiosis?
tions, select from the list above the appropriate
probability. 85. How many chromosomes would each daughter
cell have at the end of Telophase II of meiosis?
74. The probability that the next two children will
both be affected with galactosemia Questions 86-86
75. The probability that the father of the galac-
tosemic child is heterozygous for the recessive (A) Founder effect
allele (B) Kin selection
(C) Competitive exclusion
Questions 76-79 refer to the follouing cross section (D) Adaptive radiation
of a developing organism with very little yolk. (E) Convergent evolution

86. The evolution of several species from a single

species, each occupying a different niche

87. The survival, through apparently altruistic

behavior, of related individuals with common
alleles
76.Is the notochord
77.Becomes the gut 88. The establishment of a genetically unique popu-
78.Becomes the coelom lation through genetic drift
79.Gives rise to the outer skin
89. The independent development of similarities
Questions 80-83 between unrelated groups resulting from
adaptation to similar environments
(A) Angiosperms
(B) Gymnosperms
(C) Mosses
(D) Ferns
(E) Green algae

80. These represent the most primitive

tracheophytes.

81. Fruit development assists in seed dispersal.

82. These produce naked seeds.

83. The sporophyte generation consists of a foot, a

stalk and a single sporangium that remains
attached to the dominant gametophyte.
Directions: Each group of questions below concerns an experiment or laboratory situation or data. In each case
first study the description of the situation. Then choose the one best answer to each question following it and
blacken the corresponding space on the answer sheet.

Questions 90-92

A laboratory study is conducted to test the conditions under which red-spotted newts can regenerate
forelimbs. The forelimbs are amputated immediately proximal to the elbow. All the animals are maintained in
aerated pond water at 21o Celsius and are provided with equal amounts of food. The data are summarized in the
table below.

Experiment Number of Light Conditions Relative Amount of

Newts (at 100 lux) Regeneration After 8
Weeks
1 30 Constant Light Greatest
2 30 Alternating 12 hours of light Intermediate
with 12 hours of darkness
3 30 Constant Darkness Least

90. From the results of this study, it can be correctly 92. Some investigators suggest that the differences
concluded that the growth of regenerating in the growth of forelimbs described above
forelimbs is affected by reflect the amount of adrenocorticotropic
hormone secreted by the newts. To attempt to
(A) cellular respiration test this hypothesis. one should compare the
(B) exposure to light results above with those obtained from a similar
(C) the quantity of food experiment with newts
(D) the environmental temperature
(E) light intensity (A) deprived of their adrenal glands
(B) deprived of the posterior pituitary
91. To determine whether the normal functioning of glands
optic photoreceptors is involved in limb (C) deprived of their gonads
regeneration, one should compare the results (D) injected with thyroid hormones
above with those obtained from a similar (E) injected with brain extract
experiment with newts (A)
(B)
(A) that have both eyes blindfolded (C)
(B) that are maintained under constant light of (D)
1,000 lux (E)
(C) that are maintained under light of 1001ux (F)
for 6 hours and then 6 hours of darkness (G)
(D) whose forelimbs have not been amputated (H)
(E) whose olfactory nerves have been severed (I)
(J)
(K)
(L) injected with thyroid hormones
(M) injected with brain extract
Questions 93-95 refer to the pedigree below in which females are indicated by circles and males are indicated
by squares

93.The genotype of the P1 male must be 95. The most likely genotype of the mate of the F1
AO female is
(A) OO
(B) AO (A) AB
(C) BO (B) BB
(D) AB (C) OO
(E) AA (D) AA
(E) BO
94.The only other possible genotype for children of
the F1 AB male would be

(A) OO
(B) BO
(C) AO
(D) AA
(E) AB
96. Which of the diagrams represents the normal condition, in which the amount of fluid lost from capillaries
due to blood pressure is equal to the amount of fluid gained by capillaries due to osmotic pressure?

(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

97. Which of the diagrams best represents excessively high blood pressure caused by changes in blood osmotic
pressure?

(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

Questions 98-99 refer to the following graph.

98.Which of the following statements about this population is correct?

(A) This is an example of heterozygote superiority.
(B) This is an example of balanced polymorphism.
(C) The red beetles feed on the black beetles.
(D) The gene frequency of the black variety is increasing overall.
(E) There is no differential mortality.

99. The most likely conclusion from the information in the graph is that
(A) ladybird beetles mate in the fall, but the eggs do not hatch until the following spring
(B) two different species are involved
(C) there are more red beetles in the fall than in the spring of each year
(D) the allele for red color is codominant with the allele for black
(E) one variety may be adaptively superior at one time and the other variety at another time
Questions 100-101
Intact chloroplasts are isolated from blended spinach leaves by low-speed centrifugation and are
suspended in a cold, protective buffer. If these chilled chloroplasts are illuminated in the presence of an
oxidized colored dye, one may observe the reduction of the dye as the dye loses its color.

An experiment is set up to determine the optimal reduction potential of the chloroplasts under different
wavelengths of light energy. The chloroplast suspensions are individually or simultaneously exposed to the
following wavelengths of light by the use of special filters: 550 nanometers (green), 650 nanometers (red), and
700 nanometers (far-red). Ail exposures are at the same light intensity. The data are given below.

100. According to these data, which of the 101. The greatest reduction of the blue dye by two
wavelengths of light energy provides the different wavelengths of light suggests which
LEAST energy potential for photosynthesis? of the following?
(A) 550 nm onlv (A) There are two pigment systems present
(B) 650 nm only within the same chloroplast. both absorbing
(C) 700 nm only at the same waveiength.
(D) 550 nm and 650 nm (B) There are at least two pigment svstems with
(E) 650 nm and 700 nm different absorption spectra present within
the same chloroplast.
(C) Different portions of the plant (stems,
leaves, etc.) absorb light from different
wavelengths.
(D) Both red and far-red light are transmitted
by chloroplasts.
(E) Most photosynthesis occurs in green light.
Questions 102-105
Seeds given various treatments are planted in small pots. The height of each seedling is measured at
4-day intervals beginning with day 4 and ending with day 16. The graph below is an illustration of the data
obtained. A key to the seed type and treatment is shown below the graph.

D = Dwarf pea plant seeds—no treatment

DG = Dwarf pea plant seeds soaked in gibberellic acid (gibberellin)
DGA = Dwarf pea plant seeds soaked in gibberellic acid and indoleacetic acid (auxin)
T= Tall, nondwarf pea plant seeds—no treatment

102. At day 8 of the experiment, all of the following 103. A hypothesis that these data tend to support
statements are correct EXCEPT: would be that
(A) The T, DG, and DGA seedlings are very (A) tallness is dominant over dwarfness
similar in height. (B) gibberellin and auxin both stimulate cell
(B) The eventual greater height of the T elongation
seedlings over the DG seedlings is already (C) auxin promotes cell division
predictable. (D) D pea seedlings lack amounts of gibber-
(C) The D seedlings are less than half as tall as ellin sut~ficient for achieving tall stature
the other seedlings. (E) gibberellic acid alters the gene structure of
(D) The DG seedlings are taller than the T pea seeds
seedlings.
(E) The T, DG, and DGA seedlings appear to
be in a more rapid growth phase than the
D seedlings
104. After examination of the data, it could 105. Of the following, which can be concluded from
probably be safe to say that the the experimental data?
(A) differences in plant height between the T (A) The DG seedlings grew almost as tall as the
and the D plants are not significant T seedlings.
(B) D seedlings will not mature and produce (B) The T seedlings contain the greatest
new seeds concentration of auxin and gibberellin.
(C) DGA pea plants have longer internodes (C) The DGA seedlings will eventually catch
than the other plants do up in growth to the T seedlings.
(D) auxin concentration used counteracts ( D) The T seedlings are homozygous dominant
partially the action of gihberellin on the for tallness.
growth of duarf seedlings (E) There will be a less obvious height dif-
(E) stems of the T plants are not as strong as ference between DG and DGA seedlings at
those ol the DG plants 20 days than at 16 days.
Questions 106-108
The graph below shows the relationship of photosynthetic rate and irradiance (light intensity) as it is
influenced by both temperature and carbon dioxide level.

106. According to the graph, the greatest rate of 108. Which of the following seems most likely from
photosynthesis occurs when CO is present at the data?
(A) Light produces heat, which causes
(A) high concentrations and low temperatures increases in the rates of photosynthesis.
(B) low concentrations and high temperatures (B) Light causes the saturation of cytochrome
(C) high concentrations and low irradiance oxidase, which then limits the use of CO2.
levels (C) The photosynthetic rate could be increased
(D) low concentrations and high irradiance further by decreasing the CO2 concentra-
levels tion.
(E) high concentrations and high irradiance (D) Increasing irradiance levels above 800
levels Wm-2 would have less effect on the rate of
photosynthesis than would increasing the
107. From the data in the graph, which of the CO2 concentration.
following conclusions is most reasonable? (E) The rate of photosynthesis at 25oC and 660
ppm CO2 would be the same as that
(A) The rate of photosynthesis is inversely observed at 20o C and 660 ppm CO2.
proportional to light intensity.
(B) The rate of photosynthesis at 660 ppm
CO2 is more dependent on temperature
than the rate at 330 ppm CO2.
(C) There is no theoretical maximum for the
rate of photosynthesis.
(D) Attempts to increase the photosynthetic
yield in field crops should involve the
lowering of CO2, levels.
(E) Photosynthesis is unaffected by tempera-
ture.
Questions 109-111 refer to the map below of the distribution of several populations on the continents of Eurasia
and North America. These populations were derived from a common ancestral species. The area enclosed by a
given dotted line represents the distribution of the population and the numbers in millions of years refer to the
earliest fossil evidence found within the bounded area. Present populations are found only in the shaded areas.

109. The oldest existing population is found at 111. The data indicate which of the following about
the area occupied by the original species?
(A) Q (A) It increased steadily.
(B) R (B) It decreased steadily.
(C) S (C) It increased and then decreased.
(D) T (D) It decreased and then increased.
(E) U (E) It remained relatively stable.

110. The two existing populations that are

apparently the most closely related are

(A) Q and R
(B) Q and S
(C) Q and T
(D) R and U
(E) S and T
Questions 112-114

A biologist prepares an in vitro analysis of the activity of the enzyme amylase, which promotes the
hydrolysis of polysaccharides to monosaccharide residues. Three flasks containing 5 milliliters of 4 percent
amylase (starch) in water are prepared with the addition at time zero of each of the substances indicated in the
diagrams below.

112. In an experiment to test the effect of amylase 114. Support for the hypothesis of enzyme
on starch, the control would be denaturation can be obtained by comparing
starch digestion in
(A) flask A only
(B) flask B only (A) flasks A and B after 5 minutes
(C) flask C only (B) flasks B and C after 5 minutes
(D) flasks A and B (C) flasks A and C after 5 minutes
(E) flasks A and C (D) flask A at time zero and again after 5
minutes
113. After 2 minutes, a positive test for sugar would (E) flask B at time zero and again after 5
most likely be observed in minutes

(A) flask A only

(B) flask B only
(C) flask C only
(D) flasks A and C
(E) flasks B and C
 Questions 118-120 refer to the genetic code below.

118. A single substitution in the third position 120. Some geneticists consider the third base of a
would have the greatest probability of codon to be less important than the first two
mutational effect on the codon bases as a code for a specific amino acid. All of
the following observations would support this
(A) GUU hypothesis EXCEPT:
(B) AUU
(C) CGU (A) Any of the bases following a CC-
(D) AUG sequence will position a proline.
(E) CCC (B) Even though the A is replaced by a C, the
triplet AGG will still position an arginine.
119. Which amino acid has the greatest number of (C) Even though the last A is replaced by a G,
codons? the triplet UAA will still terminate a
polypeptide chain.
(A) Leucine (leu) (D) An AUU triplet codes for isoleucine, while
(B) Proline (pro) a UUU triplet codes for phenylalanine.
(C) Tryptophan (trp) (E) There are three codons, any of which will
(D) Glutamic acid (glu) position an isoleucine.
(E) Aspartic acid (asp)
 AP BIO 1986 MULTIPLE CHOICE ANSWERS

1. E 32. B 63. A 94. E

2. E 33. D 64. C 95. C

3. D 34. E 65. B 96. B

4. B 35. A 66. E 97. A

5. A 36. B 67. A 98. C

6. D 37. B 68. A 99. D

7. B 38. E 69. C 100. A

8. A 39. B 70. D 101. B

9. C 40. C 71. B 102. B

10. E 41. E 72. E 103. D

11. D 42. A 73. A 104. D

12. B 43. A 74. A 105. A

13. A 44. D 75. E 106. E

14. C 45. B 76. B 107. B

15. A 46. C 77. A 108. D

16. A 47. C 78. B 109. A

17. D 48. D 79. C 110. E

18. E 49. B 80. D 111. B

19. A 50. A 81. A 112. B

20. C 51. A 82. B 113. A

21. B 52. B 83. A 114. C

22. D 53. C 84. C 115. D

23. E 54. B 85. C 116. E

24. C 55. D 86. D 117. A

25. A 56. A 87. B 118. D

26. B 57. E 88. C 119. A

27. A 58. D 89. E 120. B

28. C 59. D 90. B

29. B 60. A 91. A

30. A 61. C 92. A

31. A 62. B 93. C