A noncompetitive inhibitor decreases the rate of an enzyme reaction by _____.
A) binding at the active site of the enzyme
B) changing the shape of the enzyme’s active site
C) changing the free energy change of the reaction
D) acting as a coenzyme for the reaction
Agrobacterium infects plants and causes them to form tumors. You are asked to
determine how long a plant must be exposed to these bacteria to become infected.
Which of the following experiments will provide the best data to address that question?
A) Determine the survival rate of Agrobacterium when exposed to different
concentrations of an antibiotic.
B) Measure the number of tumors formed on a plant when exposed to various
concentrations of Agrobacterium.
C) Measure the concentration of Agrobacterium in different soil environments where
the plants grow.
D) Measure the number of tumors formed on plants, which are exposed to
Agrobacterium for different lengths of time.
A land developer and several ecologists are discussing how a parcel of private land
should be developed while saving twenty hectares as natural habitat. The land
developer suggests that the twenty hectares be divided into twenty separate one-hectare
areas. The ecologists suggest that it would be better to have one intact parcel of twenty
hectares. What is the significance of these different arrangements of the twenty
hectares?
A) There really is no difference; they should both work equally well.
B) The isolated hectare plots increase the ability of individuals to disperse from one
habitat to another.
C) The isolated plots are more vulnerable to edge effects.
D) The large plot will create more inbreeding in many species.
Which of the following would help a virus avoid triggering an effective adaptive
immune response?
I) having frequent mutations in genes for surface proteins
II) building the viral shell from host proteins
III) producing proteins very similar to those of other viruses
IV) infecting and killing helper T cells
A) only I and III
B) only I, II, and IV
C) only I, II, and III
D) only II, III, and IV
Which of the following is true when comparing an uncatalyzed reaction to the same
reaction with a catalyst?
A) The catalyzed reaction will be slower.
B) The catalyzed reaction will have the same ∆G.
C) The catalyzed reaction will have higher activation energy.
D) The catalyzed reaction will consume all of the catalyst.
About thirteen different species of finches inhabit the Galpagos Islands today, all
descendants of a common ancestor from the South American mainland that arrived a
few million years ago. Genetically, there are four distinct lineages, but the thirteen
species are currently classified among three genera. The first lineage to diverge from
the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the
vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in
genus Camarhynchus) and six ground finch species (genus Geospiza). If the six ground
finch species have evolved most recently, then which of these is the most logical
prediction?
A) They should be limited to the six islands that most recently emerged from the sea.
B) Their genomes should be more similar to each other than are the genomes of the five
tree finch species.
C) They should share fewer anatomical homologies with each other than they share
with the tree finches.
D) The chances of hybridization between two ground finch species should be less than
the chances of hybridization between two tree finch species.
Which of the following contain the 9 + 2 arrangement of microtubules, consisting of
nine doublets of microtubules surrounding a pair of single microtubules?
A) motile cilia and primary (nonmotile) cilia
B) flagella and motile cilia
C) basal bodies and primary (nonmotile) cilia
D) centrioles and basal bodies
SRY is best described as _____.
A) a gene present on the X chromosome that triggers female development
B) an autosomal gene that is required for the expression of genes on the Y chromosome
C) a gene region present on the Y chromosome that triggers male development
D) an autosomal gene that is required for the expression of genes on the X chromosome
From the figure above, what can we determine about the location of the food source?
A) The waggle dance in the top figure indicates that the food is directly under the hive.
B) The waggle dance in the bottom figure indicates that the food is to the west of the
hive.
C) The waggle dance in the top figure indicates that the food is close to the hive.
D) The waggle dance in the bottom figure indicates that the food is 90 degrees to the
right of the Sun.
Which of the following groups is matched with a correct anatomical feature?
A) foraminifera → silicon-rich tests
B) dinoflagellata → holdfast
C) diatoms → tests made of cellulose
D) phaeophyta (brown algae) → blade
The tRNA shown in the figure above has its end projecting beyond its end. What
will occur at this end?
A) The amino acid binds covalently.
B) The excess nucleotides (ACCA) will be cleaved off at the ribosome.
C) The small and large subunits of the ribosome will attach to it.
D) The cap of the mRNA will become covalently bound.
Some human infants, especially those born prematurely, suffer serious respiratory
failure because of _____.
A) the sudden change from the uterine environment to the air
B) the overproduction of surfactants
C) lung collapse due to inadequate production of surfactant
D) mutations in the genes involved in lung formation
Imagine that a woman is in the final week of her pregnancy. Her doctor gives her an
injection of oxytocin. The likely result of this is that the pregnant woman would _____.
A) stop secreting prostaglandins from the placenta
B) undergo vigorous contractions of her uterine muscles
C) increase the synthesis and secretion of progesterone
D) be prevented from lactation
Which of the following is the best natural example of uniform distribution?
A) bees collecting pollen in a wildflower meadow
B) snails in an intertidal zone at low tide
C) territorial songbirds in a mature forest during mating season
D) mushrooms growing on the floor of an old growth forest
Refer to the drawings in the figure below of a single pair of homologous chromosomes
as they might appear during various stages of either mitosis or meiosis, and answer the
following questions.
Which diagram represents anaphase II of meiosis?
A) I
B) III
C) IV
D) V
All animals, whether large or small, have _____.
A) an external body surface that is dry
B) a basic body plan that resembles a two-layered sac
C) a body surface covered with hair to keep them warm
D) most of their cells in contact with an aqueous medium
Giardia intestinalis can cause disease in several different mammalian species, including
humans. Giardia organisms (G. intestinalis) that infect humans are similar
morphologically to those that infect other mammals; thus they have been considered a
single species. However, G. intestinalis has been divided into different subgroups based
on their host and a few other characteristics.
In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups
actually constitute different species. The following phylogenetic tree was constructed
from the sequence comparison of rRNA from several subgroups of G. intestinalis and a
few other morphologically distinct species of Giardia. The researchers concluded that
the subgroups of Giardia are sufficiently different from one another genetically that
they could be considered different species. (T. Monis et al. 1999. Molecular systematics
of the parasitic protozoan Giardia intestinalis. Mol. Biol. Evol. 16[9]:1135-44.)
According to the phylogenetic tree in the figure above, G. intestinalis constitutes a
_____ group.
A) paraphyletic
B) monophyletic
C) polyphyletic
Which of the following best describes what occurred after the publication of Charles
Darwin’s On the Origin of Species?
A) The publisher was pressured to cease distribution.
B) The book was banned from schools.
C) The book was widely discussed and disseminated.
D) The book was discredited by most scientists.
Arrange the following structures from largest to smallest, assuming that they belong to
two generations of the same angiosperm.
1. ovary
2. ovule
3. egg
4. carpel
5. embryo sac
A) 4, 2, 1, 5, 3
B) 5, 4, 3, 1, 2
C) 5, 1, 4, 2, 3
D) 4, 1, 2, 5, 3
One way to understand how early environment influences behaviors in similar species
is through the “cross-fostering” experimental technique. Suppose that the
curly-whiskered mud rat differs from the bald mud rat in several ways, including being
much more aggressive. How would you set up a cross-fostering experiment to
determine if environment plays a role in the curly-whiskered mud rat’s aggression?
A) You would cross curly-whiskered mud rats and bald mud rats and hand-rear the
offspring to see if any grew up to be aggressive.
B) You would place newborn curly-whiskered mud rats with bald mud rat parents and
place newborn bald mud rats with curly-whiskered mud rat parents. Finally, let some
mud rats of both species be raised by their own species. Then you would compare the
outcomes.
C) You would remove the offspring of curly-whiskered mud rats and bald mud rats
from their parents, raise them in the same environment but without parents, and then
compare the outcomes.
D) You would replace normal newborn mud rats with deformed newborn mud rats to
see if it triggered an altruistic response.
Which of the following does NOT occur during mitosis?
A) condensation of the chromosomes
B) replication of the DNA
C) spindle formation
D) separation of the spindle poles
Which of the following statements correctly describes a portion of the pine life cycle?
A) Female gametophytes use mitosis to produce eggs.
B) Seeds are produced in pollen-producing cones.
C) Pollen grains contain female gametophytes.
D) A pollen tube slowly digests its way through the triploid endosperm.
Use the following diagram of five islands formed at around the same time near a
particular mainland, as well as MacArthur and Wilson’s island biogeography principles,
to answer the question(s) below.
Which island would likely have the lowest extinction rate?
A) A
B) C
C) D
D) E
Which of the following best describes the relationship between the atoms described
below?
A) They are isomers.
B) They are isotopes.
C) They contain 1 and 3 protons, respectively.
D) They each contain only 1 neutron.
An individual plant was discovered that could not grow towards light. After some
research, it was determined that the reason was a defective gene that did not allow for
the level of cell elongation necessary for a phototropic response. This mutation greatly
reduces the fitness of the individual plant. Which reason best describes the reason for
the loss of fitness?
A) The plant was too short to attract insects for pollination.
B) The plant could not adjust to directional light, which reduced photosynthetic activity
and therefore energy available for reproduction.
C) Because the plant grew much taller and straighter, resources that could be used for
reproduction were used for growth.
D) The loss of a phototropic response meant that the plant’s seeds could not germinate
so reproduction would be unsuccessful.
A flask containing photosynthetic green algae and a control flask containing water with
no algae are both placed under a bank of lights, which are set to cycle between 12 hours
of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are
monitored. Predict what the relative dissolved oxygen concentrations will be in the
flask with algae compared to the control flask. The dissolved oxygen in the flask with
algae will _____.
A) always be higher
B) always be lower
C) be higher in the light, but the same in the dark
D) be higher in the light, but lower in the dark
Researchers tested nitrogen loss from soil where the moss Dawsonia was growing, and
compared it to soil from which Dawsonia had been removed. The data are presented
below.
Researchers decided to test the hypothesis that if the 1-meter-tall Dawsonia
gametophyte-sporophyte plants had acted as a physical buffer, then they would have
reduced water’s ability to erode the soil and carry away its nitrogen. They began with
four equal-sized areas where Dawsonia mosses grew to a height of 1 m above the soil
surface. One of the four areas was not modified. In the second area, the mosses were
trimmed to a height of 0.5 m above the soil surface. In the third area, the mosses were
trimmed to a height of 0.25 m above the soil surface. In the fourth area, the mosses
were trimmed all the way to the ground, leaving only the rhizoids. Water, simulating
rainfall, was then added in a controlled fashion to all plots over the course of one year.
The figure below presents four graphs that depict potential results of this experiment.
Soil nitrogen is not solely contained within the rhizoids of the Dawsonia mosses
because rhizoids _____.
A) are associated with fungi that inhibit mineral transfer from soil to rhizoids
B) are not absorptive structures
C) lack direct attachment to the moss sporophytes
D) immediately transfer the nitrogen to the sporophyte
During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a
∆G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be
the ∆G for the new reaction?
A) -40 kcal/mol
B) -20 kcal/mol
C) 0 kcal/mol
D) +20 kcal/mol
Female spotted sandpipers aggressively court males and, after mating and egg laying,
leave the clutch of young for the male to incubate. This sequence may be repeated
several times with different males until no available males remain, forcing the female to
incubate her last clutch. Which of the following terms best describes this behavior?
A) monogamy
B) polygyny
C) polyandry
D) promiscuity
Which of these are amniotes?
A) amphibians
B) fishes
C) turtles
D) lungfish
Consider this pathway: epinephrine → G protein-coupled receptor → G protein →
adenylyl cyclase → cAMP. The second messenger in this pathway is _____.
A) cAMP
B) G protein
C) adenylyl cyclase
D) G protein-coupled receptor