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Which of these are spore-producing structures?
A) sporophyte (capsule) of a moss
B) antheridium of a moss or fern
C) archegonium of a moss or fern
D) gametophyte of a moss
P680+ is said to be the strongest biological oxidizing agent. Given its function, why is
this necessary?
A) It is the receptor for the most excited electron in either photosystem of
photosynthesis.
B) It is the molecule that transfers electrons to plastoquinone (Pq) of the electron
transfer system.
C) It transfers its electrons to reduce NADP+ to NADPH.
D) It obtains electrons from the oxygen atom in a water molecule, so it must have a
stronger attraction for electrons than oxygen has.
The middle ear converts _____.
A) air pressure waves to fluid pressure waves
B) fluid pressure waves to air pressure waves
C) air pressure waves to nerve impulses
D) fluid pressure waves to nerve impulses
In terms of food capture, which sponge cell is most similar to the cnidocyte of a
cnidarian?
A) amoebocyte
B) choanocyte
C) epidermal cell
D) pore cell
Plants do not have a circulatory system like that of some animals. If a water molecule in
a plant did "circulate" (that is, go from one point in a plant to another and back in the
same day), it would require the activity of _____.
A) only the xylem
B) only the phloem
C) only the endodermis
D) both the xylem and the phloem
Evidence suggests that factors which contribute towards the virulence of E. coli strain
O157:H7, a bacterial strain reported to cause several food poisoning deaths, are caused
by genes from a virus that infects bacteria. Considering this evidence, which statement
most likely explains how the O157:H7 population acquired the genetic variation that
distinguishes the strain from harmless E. coli strains, such as those that reside in our
intestines?
A) The virus entered the bacterial cell and incorporated its DNA into the bacterial
genome, allowing the bacteria's cellular machinery to create new viruses.
B) Viral envelope proteins bind to receptors on the bacterial membrane, allowing the
viral genetic material to enter the bacterium and become translated into proteins.
C) The virus entered the cell and acquired specific genes from the bacteria to increase
the virulence of the virus.
D) The virus infected the bacterium, and allowed the bacterial population to replicate
with a copy of the phage genome in each new bacterium.
Some fungal species can kill herbivores while feeding off of sugars from its plant host.
What type of relationship does this fungus have with its host?
A) parasitic
B) mutualistic
C) commensal
D) predatory
The difference between ATP and the nucleoside triphosphates used during DNA
synthesis is that _____.
A) the nucleoside triphosphates have the sugar deoxyribose; ATP has the sugar ribose
B) the nucleoside triphosphates have two phosphate groups; ATP has three phosphate
groups
C) ATP contains three high-energy bonds; the nucleoside triphosphates have two
D) ATP is found only in human cells; the nucleoside triphosphates are found in all
animal and plant cells
Why do logged tropical rain forest soils typically have nutrient-poor soils?
A) Tropical bedrock contains little phosphorous.
B) Logging results in soil temperatures that are lethal to nitrogen-fixing bacteria.
C) Most of the nutrients in the ecosystem are removed in the harvested timber.
D) The cation exchange capacity of the soil is reversed as a result of logging.
The umami receptor in the sense of taste detects _____.
A) glucose
B) potassium ions
C) hydrogen ions
D) monosodium glutamate
Feather color in budgies is determined by two different genes, Y and B, one for pigment
on the outside and one for the inside of the feather. YYBB, YyBB, or YYBb is green;
yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. A blue budgie is
crossed with a white budgie. Which of the following results is NOTpossible?
A) green offspring only
B) yellow offspring only
C) blue offspring only
D) green and yellow offspring
A species that has a normal resting systolic blood pressure of greater than 260 mm Hg
is likely to be _____.
A) an animal that is small and compact, without the need to pump blood very far from
the heart
B) a species that has very wide diameter veins
C) an animal that has a very long distance between its heart and its brain
D) an animal that makes frequent, quick motions
How would you expect the root system of a plant grown by hydroponics to compare to
the root system of a plant grown in soil? The root system of a plant grown by
hydroponics would be _____.
A) more developed
B) less developed
C) about the same
D) absent
Through studies of insect Malpighian tubules, researchers found that K+ accumulated
on the inner face of the tubule, against its concentration gradient. What can you infer
about the mechanism of transport?
A) Potassium transport is a passive process.
B) Movement of potassium into the lumen of the Malpighian tubules is an
energy-requiring process.
C) Potassium moves out of the tubules at a faster rate than it moves into the lumen of
the tubules.
D) Sodium ions will follow potassium ions.
What adaptations should one expect of the seed coats of angiosperm species whose
seeds are dispersed by frugivorous (fruit-eating) animals, as opposed to angiosperm
species whose seeds are dispersed by other means?
1. The exterior of the seed coat should have barbs or hooks.
2. The seed coat should contain secondary compounds that irritate the lining of the
animal's mouth.
3. The seed coat should be able to withstand low pHs.
4. The seed coat, upon its complete digestion, should provide vitamins or nutrients to
animals.
5. The seed coat should be resistant to the animals' digestive enzymes.
A) 4 only
B) 1 and 2
C) 2 and 3
D) 3 and 5
The data were obtained from a study of the length of time spent in each phase of the
cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma.
Minutes Spent in Cell Cycle Phases
Neurons and some other specialized cells divide infrequently because they _____.
A) no longer have active nuclei
B) have entered into G0
C) can no longer bind Cdk to cyclin
D) show a drop in MPF concentration
Bacteria perform each of the following ecological roles. Which role typically does NOT
involve symbiosis?
A) skin commensalist
B) decomposer
C) aggregates with methane-consuming archaea
D) gut mutualist
A plantlike organism on the planet Pandora can have three recessive genetic traits:
bluish leaves, due to an allele (a) of gene A; a feathered stem, due to an allele (b) of
gene B; and hollow roots due to an allele (c) of gene C. The three genes are linked and
recombine as follows:
A geneticist did a testcross with an organism that had been found to be heterozygous for
the three recessive traits and she was able to identify progeny of the following
phenotypic distribution (+ = wild type):
Which of the progeny phenotypes will require recombination between genes A and B?
A) 1, 2, 5, and 6
B) 1, 3, 6, and 7
C) 2, 4, 5, and 8
D) 2, 3, 5, and 7
What event accompanies energy absorption by chlorophyll (or other pigment molecules
of the antenna complex)?
A) ATP is synthesized from the energy absorbed.
B) A carboxylation reaction of the Calvin cycle occurs.
C) Electrons are stripped from NADPH.
D) An electron is excited.
Compared to oxidative skeletal muscle fibers, those classified as glycolytic typically
have _____.
A) a higher concentration of myoglobin
B) a higher density of mitochondria
C) a smaller diameter
D) less resistance to fatigue
In eukaryotic cells, chromosomes are composed of _____.
A) DNA and RNA
B) DNA only
C) DNA and proteins
D) DNA and phospholipids
This nudibranch, a type of sea slug, has many reddish cerata on its dorsal surface, as
well as two white-tipped rhinophores located on the head.
The nontaxonomic term sea slug encompasses a wide variety of marine gastropods.
One feature they share as adults is the lack of a shell. We might think, therefore, that
they represent defenseless morsels for predators. In fact, sea slugs have multiple
defenses. Some sea slugs prey on sponges and concentrate sponge toxins in their
tissues. Others feed on cnidarians, digesting everything except the nematocysts, which
they then transfer to their own skins. Whereas the most brightly colored sea slugs are
often highly toxic, others are nontoxic and mimic the coloration of the toxic species.
Their colors are mostly derived from pigments in their prey. There are also sea slugs
that use their coloration to blend into their environments.
The nematocysts of sea slugs should be most effective at protecting individual sea slugs
from predation if the predators _____.
A) remove small bites of flesh from sea slugs and have long-term memory
B) remove small bites of flesh from sea slugs and have no long-term memory
C) consume entire sea slugs in one gulp and have no long-term memory
D) consume entire sea slugs in one gulp and have long-term memory
The figure above shows a nephron. Filtration takes place in the structure labeled _____.
A) a
B) b
C) c
D) d
Suzanne Simard and colleagues knew that the same mycorrhizal fungal species could
colonize multiple types of trees. They wondered if the same fungal individual would
colonize different trees, forming an underground network that potentially could
transport carbon and nutrients from one tree to another (S. Simard et al. 1997. Net
transfer of carbon between mycorrhizal tree species in the field. Nature 388:579-82).
Figure A illustrates the team's experimental setup. Pots containing seedlings of three
different tree species were set up and grown under natural conditions for three years;
two of the three species (Douglas fir, birch) formed ectomycorrhizae and the other
(cedar) formed arbuscular mycorrhizae. For the experiment, the researchers placed
airtight bags over the Douglas fir and birch seedlings; into each bag, they injected either
carbon dioxide made from carbon-13 or carbon-14 (13CO2 and 14CO2, isotopes of
carbon). As the seedlings photosynthesized, the radioactive carbon dioxide was
converted into radioactively labeled sugars that could be tracked and measured by the
researchers.
Figure A
Figure B
Referring to Simard et al. (1997), what is the result that would most strongly refute their
hypothesis? [Hypothesis: Sugars made by one plant during photosynthesis can travel
through a mycorrhizal fungus and be incorporated into the tissues of another plant.]
A) No movement: Carbon-14 is found in the birch seedling's tissues and carbon-13 in
the Douglas fir.
B) Reciprocal exchange: Carbon-14 is found in the Douglas fir seedling's tissues and
carbon-13 in the birch.
C) Either carbon-13 or carbon-14 is found in the fungal tissues.
D) Either carbon-13 or carbon-14 is found in the cedar seedling's tissues.
Estrogens found in the environment have raised concerns about effects on reproductive
health of animals. Researchers studied the effects that estrogens in the water have on
sexual differentiation in zebrafish. They exposed embryo-larval (0-21 days
post-hatching), juvenile (21-42 days post-hatching), and adult (over 200 days
post-hatching) fish to three concentrations of 17β-estradiol (5, 25, and 100
nanograms/liter) that are within the range of concentrations found in water leaving
sewage treatment plants in different countries. They then examined the proportion of
males and females when the fish exposed at embryo-larval and juvenile stages reached
adulthood. Embryo-larval stage fish that had been exposed to 100 ng/l 17β-estradiol
resulted in adult populations that had substantially more females than males compared
to control groups. Embryo-larval fish that had been exposed to 5 and 25 ng/l of
17β-estradiol did not show a statistically significant shift in the proportion of females.
(Brion, F., C. R. Tyler, X. Palazzi, B. Laillet, J. M. Porcher, J. Garric, and P.
Flammarion. 2004. Impacts of 17β-estradiol, including environmentally relevant
concentrations, on reproduction after exposure during embryo-larval-, juvenile-, and
adult-life stages in zebrafish (Danio rerio). Aquatic Toxicology 68:193-217.)
Refer to the paragraph on the effects of estrogens in the environment. What is the
significance of using the concentrations of 5, 25, and 100 ng/l of 17β-estradiol for the
dose in this experiment?
A) These concentrations are similar to those found in many animals.
B) These concentrations are found in the environment.
C) These concentrations are effective, yet not lethal to the fish.
D) These concentrations are standard in toxicology assays.
Which of the following flower parts develops into the pulp of a fleshy fruit?
A) stigma
B) style
C) ovule
D) ovary
In E. coli, what is the function of DNA polymerase III?
A) to unwind the DNA helix during replication
B) to seal together the broken ends of DNA strands
C) to add nucleotides to the end of a growing DNA strand
D) to degrade damaged DNA molecules
We know the streamlined bodies shown in the figure above are examples of homoplasy.
If the following groups also had streamlined bodies, which of the groupings would give
the most support to this body type being homologous?
A) lizards and elephants
B) pterosaurs, dinosaurs, and birds
C) synapsids, monotremes, marsupials, rodents, and primates
D) lizards, pterosaurs, dinosaurs, birds, synapsids, monotremes, marsupials, rodents,
and primates
Which of the following sequences correctly represents the flow of electrons during
photosynthesis?
A) NADPH → O2 → C O2
B) H2O → NADPH → Calvin cycle
C) NADPH → chlorophyll → Calvin cycle
D) NADPH → electron transport chain → O2
If an animal cell suddenly lost the ability to produce GTP, what might happen to its
signaling system?
A) It would not be able to activate and inactivate the G protein on the cytoplasmic side
of the plasma membrane.
B) It would be able to carry out reception and transduction but would not be able to
respond to a signal.
C) It would use ATP instead of GTP to activate and inactivate the G protein on the
cytoplasmic side of the plasma membrane.
D) It would employ a transduction pathway directly from an external messenger.
You are confronted with a box of preserved grasshoppers of various species that are
new to science and have not been described. Your assignment is to separate them into
species. There is no accompanying information as to where or when they were
collected. Which species concept will you have to use?
A) biological
B) phylogenetic
C) ecological
D) morphological
If glucose is the sole energy source, what fraction of the carbon dioxide exhaled by
animals is generated by the reactions of the citric acid cycle?
A) 1/6
B) 1/3
C) 2/3
D) all of it
A given photon of light may trigger an action potential with thousands of times more
energy because the signal strength is amplified by _____.
A) the receptor
B) a G protein
C) a signal transduction pathway
D) triggering several receptors at once
