In an analysis of the nucleotide composition of DNA, which of the following will be
found?
A) A = C
B) A = G and C = T
C) A + C = G + T
D) G + C = T + A
An elementary school science teacher decided to liven up the classroom with a
saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher
proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided
to stock the tank with various marine invertebrates, including a polychaete, a siliceous
sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial
hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod
varieties. Lastly, she added some vertebratesa parrotfish and a clownfish. She arranged
for daily feedings of copepods and feeder fish.
The bivalves started to die one by one; only the undamaged shells remained. To keep
the remaining bivalves alive, the teacher would most likely need to remove the _____.
A) sea anemones
B) sea star
C) gastropods
D) ectoprocts
Which of the following correctly describes a reaction that has reached chemical
equilibrium?
A) The rate of the forward reaction is equal to the rate of the reverse reaction.
B) All of the reactants have been converted to the products of the reaction.
C) All of the products have been converted to the reactants of the reaction.
D) Both the forward and the reverse reactions have stopped, with no net effect on the
concentration of the reactants and the products.
Chordate pharyngeal slits appear to have functioned first as _____.
A) the digestive system’s opening
B) suspension-feeding devices
C) components of the jaw
D) sites of respiration
How is natural selection related to sexual reproduction as opposed to asexual
reproduction?
A) Sexual reproduction results in many new gene combinations, some of which will
lead to differential reproduction.
B) Sexual reproduction results in the greatest number of new mutations.
C) Sexual reproduction allows the greatest number of offspring to be produced.
D) Sexual reproduction utilizes far less energy than asexual reproduction.
Which of the following is the best modern definition of evolution?
A) descent with modification
B) change in the number of genes in a population over time
C) survival of the fittest
D) inheritance of acquired characters
According to the figure above, what is the LEAST likely explanation for the data after
1985?
A) emigration
B) immigration
C) introduction of new alleles into the population
D) increased resources in the area
Who performed classic experiments that supported the semiconservative model of DNA
replication?
A) Watson and Crick
B) Meselson and Stahl
C) Hershey and Chase
D) Franklin and Wilkins
Which of the following statements about NAD+ is true?
A) NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid
cycle.
B) NAD+ has more chemical energy than NADH.
C) NAD+ can donate electrons for use in oxidative phosphorylation.
D) In the absence of NAD+, glycolysis can still function.
Viagra causes dilation of blood vessels and increased blood flow to the penis,
facilitating erection. Viagra acts by inhibiting _____.
A) the hydrolysis of cGMP to GMP
B) the hydrolysis of GTP to GDP
C) the dephosphorylation of cGMP
D) the removal of GMP from the cell
Shoots that grow vertically toward the sun can be characterized as _____.
A) positive for phototropism and negative for gravitropism
B) neutral for phototropism and positive for gravitropism
C) negative for phototropism and positive for gravitropism
D) positive for phototropism and neutral for gravitropism
Big Bend National Park in Texas is mostly Chihuahuan desert, where rainfall averages
about 10 inches per year. Yet, it is not uncommon when hiking in this bone-dry desert to
encounter mosses and ferns. One such plant is called “flower of stone.” It is not a
flowering plant, nor does it produce seeds. Under arid conditions, its leaflike structures
curl up. However, when it rains, it unfurls its leaves, which form a bright green rosette
on the desert floor. Consequently, it is sometimes called the “resurrection plant.” At first
glance, it could be a fern, a true moss, or a spike moss.
What feature of both true mosses and ferns makes it most surprising that they can
survive for many generations in dry deserts?
A) flagellated sperm
B) lack of vascular tissues
C) lack of true roots
D) lack of cuticle
Which of the following is the most inclusive (most general) group in which all of the
members have fully opposable thumbs?
A) apes
B) Homo
C) anthropoids
D) primates
A sediment core is removed from the floor of an inland sea. The sea has been in
existence, off and on, throughout the entire time that terrestrial life has existed.
Researchers wish to locate and study the terrestrial organisms fossilized in this core.
The core is illustrated as a vertical column, with the top of the column representing the
most recent strata and the bottom representing the time when land was first colonized
by life.
If arrows indicate locations in the column where fossils of a particular type (see key
above) first appear, then which core in the figure above has the most accurate
arrangement of fossils?
A) core A
B) core B
C) core C
D) core D
The largest unit within which gene flow can readily occur is _____.
A) a population
B) a species
C) the entire range of a genus
D) the hybrid zone
If you found a vertebrate skull in the woods and the teeth were sharp and scissor-like,
what type of food would you expect this animal to eat?
A) grass
B) flesh of another animal
C) nectar
D) blood
Your brother has just purchased a new plastic model airplane. He places all the parts on
the table in approximately the positions in which they will be located when the model is
complete. His actions are analogous to which process in development?
A) morphogenesis
B) determination
C) differentiation
D) pattern formation
Activity of various enzymes at various temperatures (a) and at various pH (b).
Which temperature and pH profile curves on the graphs were most likely generated
from analysis of an enzyme from a human stomach where conditions are strongly acid?
A) curves 1 and 4
B) curves 1 and 5
C) curves 2 and 4
D) curves 3 and 4
The bile salts _____.
A) are enzymes
B) are manufactured by the pancreas
C) emulsify fats in the duodenum
D) are normally an ingredient of gastric juice
Unlike eutherians, both monotremes and marsupials _____.
A) lack nipples
B) have some embryonic development outside the uterus
C) lay eggs
D) are found in Australia and Africa
When a mycelium infiltrates an unexploited source of dead organic matter, what are
most likely to appear within the food source soon thereafter?
A) fungal haustoria
B) fungal enzymes
C) increased oxygen levels
D) larger bacterial populations
In angiosperms, which number in the figure above represents a component contributing
to the formation of endosperm?
A) 1
B) 7
C) 9
D) 11
When the body’s blood glucose level rises, the pancreas secretes insulin and, as a result,
the blood glucose level declines. When the blood glucose level is low, the pancreas
secretes glucagon and, as a result, the blood glucose level rises. Such regulation of the
blood glucose level is the result of _____.
A) catalytic feedback
B) positive feedback
C) negative feedback
D) protein-protein interactions
Which of the following problems with animal cloning might result in premature death
of the clones?
A) use of pluripotent instead of totipotent stem cells
B) use of nuclear DNA as well as mtDNA
C) abnormal gene regulation due to variant methylation
D) the indefinite replication of totipotent stem cells
Vines in tropical rain forests must grow toward large trees before being able to grow
toward the sun. To reach a large tree, the most useful kind of growth movement for a
tropical vine presumably would be_____.
A) negative thigmotropism
B) negative phototropism
C) negative gravitropism
D) the opposite of circadian rhythms
Engulfing-phagocytic cells of innate immunity of vertebrates include _____.
I) neutrophils
II) macrophages
III) dendritic cells
IV) natural killer cells
A) I and III
B) II and IV
C) I and IV
D) I, II, and III
Celery stalks that are immersed in fresh water for several hours become stiff. Similar
stalks left in a 0.15 M salt solution become limp. From this we can deduce that the fresh
water_____.
A) and the salt solution are both hypertonic to the cells of the celery stalks
B) is hypotonic and the salt solution is hypertonic to the cells of the celery stalks
C) is hypertonic and the salt solution is hypotonic to the cells of the celery stalks
D) is isotonic and the salt solution is hypertonic to the cells of the celery stalks
Gray seed color in peas is dominant to white. Assume that Mendel conducted a series of
experiments where plants with gray seeds were crossed among themselves, and the
following progeny were produced: 302 gray and 98 white.
(a) What is the most probable genotype of each parent?
(b) Based on your answer in (a) above, what genotypic and phenotypic ratios are
expected in these progeny? (Assume the following symbols: G = gray and g = white.)
A) (a) GG x gg; (b) genotypic = 3:1, phenotypic = 1:2:1
B) (a) Gg x Gg; (b) genotypic = 1:2:1, phenotypic = 3:1
C) (a) GG x Gg; (b) genotypic = 1:2:1, phenotypic = 2:1
D) (a) gg x Gg; (b) genotypic = 1:2, phenotypic = 3:1
If we were to apply the most recent technique used to fight potato late blight to the fight
against the malarial infection of humans, then we would _____.
A) increase the dosage of the least-expensive antimalarial drug administered to humans
B) introduce a predator of the malarial parasite into infected humans
C) use a “cocktail” of at least three different pesticides against Anopheles mosquitoes
D) insert genes from a Plasmodium-resistant strain of mosquito into Anopheles
mosquitoes
A hypothetical island lies far from any other landmasses. There are many different types
of plants, but only one animal, a beetle, that can fly or walk from plant to plant and
feeds by chewing leaves. Given that the beetle is not exploiting all of the resources on
the island, which morphological change would be most likely to trigger an adaptive
radiation of the beetles?
A) a change in wing shape that improves flight speed
B) an additional segment on a pair of legs
C) a mouthpart that can pierce fruits and seeds
If an organism was discovered that had no epithelial tissues, it would require
adaptations to maintain homeostasis in which of the following areas? The organism
would require adaptations _____.
A) in its skeleton for structure
B) in its nervous system for sensing external stimuli
C) that would prevent water loss from the body in a terrestrial environment
D) in its muscular system for movement