Which of the following characteristics are expected in the first animals to have
colonized land?
1. were probably herbivores (ate photosynthesizers)
2. had four appendages
3. had the ability to resist dehydration
4. had lobe-finned fishes as ancestors
5. were invertebrates
A) 3 only
B) 3 and 5
C) 1, 3, and 5
D) 1, 2, 3, and 4
Treehoppers (a type of insect) produce honeydew, which ants use for food. Treehoppers
have a major predator, the jumping spider. Researchers hypothesized that the ants
would protect the treehoppers from the spiders. In an experiment, researchers followed
study plots with ants removed from the system and compared them to a control plot. In
the figure above, what can you conclude?
A) Ants do somehow protect the treehoppers from spiders.
B) Ants eat the honeydew produced by treehoppers
C) Ants reduce the numbers of treehoppers.
D) No specific conclusions can be drawn from this figure.
According to the nonequilibrium model of community diversity, _____.
A) community structure remains stable in the absence of interspecific competition
B) communities are assemblages of closely linked species that are irreparably changed
by disturbance
C) interspecific interactions induce changes in community composition over time
D) communities are constantly changing after being influenced by disturbances
Which of the following is a potential advantage of introducing apomixis into hybrid
crop species?
A) Cultivars would be better able to cope with a rapidly changing environment.
B) They would have a larger potential genome than inbred crops.
C) All of the desirable traits of the cultivar would be passed on to offspring.
D) They would benefit from positive mutations in their DNA.
Genetic mutations in asexually reproducing organisms lead to more evolutionary
change than do genetic mutations in sexually reproducing ones because _____.
A) asexually reproducing organisms, but not sexually reproducing organisms, pass all
mutations on to their offspring
B) sexually reproducing organisms can produce more offspring in a given time than can
asexually reproducing organisms
C) more genetic variation is present in organisms that reproduce asexually than is
present in those that reproduce sexually
D) asexually reproducing organisms have more dominant genes than organisms that
reproduce sexually
Two plant species live in the same biome but on different continents. Although the two
species are not at all closely related, they may appear quite similar as a result of _____.
A) convergent evolution
B) allopatric speciation
C) introgression
D) gene flow
Which of the following includes all of the pyrimidines found in RNA and DNA?
A) cytosine and uracil
B) cytosine and thymine
C) cytosine, uracil, and thymine
D) cytosine, uracil, and guanine
The body fluids of an osmoconformer would be _____ with its _____ environment
A) isoosmotic; freshwater
B) hyperosmotic; saltwater
C) isoosmotic; saltwater
D) hypoosmotic; saltwater
Chum salmon (Oncorhynchus keta) are born in freshwater environments and then
migrate to the sea. Near the end of their lives, they return to the freshwater stream
where they were born to spawn. In freshwater, water constantly diffuses into the body
and ions are lost from the body. In salt water, body water diffuses out of the body and
excess ions are gained from the water. A salmon’s gills have special cells to pump salt in
or out of the body to maintain homeostasis. In response to the salmon’s moves between
freshwater and salt water, some cells in the gills are produced and others are destroyed.
These changes made in the cells of the gills during the lifetime of an individual salmon
are an example of which of the following?
A) evolution
B) trade-off
C) acclimatization
D) adaptation
Ignoring all other factors, what kind of day would result in the fastest delivery of water
and minerals to the leaves of an oak tree?
A) cool, dry day
B) very hot, dry, windy day
C) warm, humid day
D) cool, humid day
The fastest possible conduction velocity of action potentials is observed in _____.
A) thin, non-myelinated neurons
B) thin, myelinated neurons
C) thick, non-myelinated neurons
D) thick, myelinated neurons
When a woman has her gallbladder removed, she should probably reduce her
consumption of _____.
A) proteins
B) carbohydrates
C) fats
D) proteins and carbohydrates
Which of the following could use reverse transcriptase to transcribe its genome?
A) ssRNA
B) dsRNA
C) ssDNA
D) dsDNA
Structures as different as human arms, bat wings, and dolphin flippers contain many of
the same bones, which develop from similar embryonic tissues. These structural
similarities are an example of _____.
A) homology
B) convergent evolution
C) the evolution of common structure as a result of common function
D) the evolution of similar appearance as a result of common function
Transcription factors _____.
A) regulate the synthesis of DNA in response to a signal
B) transcribe ATP into cAMP
C) control gene expression
D) regulate the synthesis of lipids in the cytoplasm
Food chains are sometimes short because _____.
A) only a single species of herbivore feeds on each plant species
B) local extinction of a species causes extinction of the other species in its food chain
C) most of the energy in a trophic level is lost as it passes to the next higher level
D) predator species tend to be less diverse and less abundant than prey species
What would be the most effective method of reducing the incidence of blood flukes in a
human population?
A) reduce the mosquito population
B) reduce the population of the intermediate snail host
C) avoid contact with rodent droppings
D) carefully wash all raw fruits and vegetables
Of the following anatomical structures, which is homologous to the bones in the wing
of a bird?
A) bones in the hind limb of a kangaroo
B) chitinous struts in the wing of a butterfly
C) bony rays in the tail fin of a flying fish
D) bones in the flipper of a whale
Cells move to new positions as an embryo establishes its three germ-tissue layers
during _____.
A) determination
B) cleavage
C) induction
D) gastrulation
Similar to most amoebozoans, the forams and the radiolarians also have pseudopods, as
do some of the white blood cells of animals (monocytes). If one were to erect a taxon
that included all organisms that have cells with pseudopods, the taxon would _____.
A) be polyphyletic
B) be paraphyletic
C) be monophyletic
D) include all eukaryotes
What is the importance of consuming an adequate amount of proteins in the diet?
A) They are most commonly used to meet energy demands of cells.
B) Proteins serve a variety of functions, and the body does not store excess quantities of
protein.
C) They are used as cofactors for metabolic reactions and are required in minute
quantities.
D) Proteins are necessary to produce urea and other important metabolites.
The following steps refer to various stages in transmission at a chemical synapse.
1. Neurotransmitter binds with receptors associated with the postsynaptic membrane.
2. Calcium ions rush into neuron’s cytoplasm.
3. An action potential depolarizes the membrane of the presynaptic axon terminal.
4. The ligand-gated ion channels open.
5. The synaptic vesicles release neurotransmitter into the synaptic cleft.
Which sequence of events is correct?
A) 1 → 2 → 3 → 4 → 5
B) 2 → 3 → 5 → 4 → 1
C) 3 → 2 → 5 → 1 → 4
D) 4 → 3 → 1 → 2 → 5
The panting responses that are observed in overheated birds and mammals dissipate
excess heat by _____.
A) countercurrent exchange
B) acclimation
C) vasoconstriction
D) evaporation
Which of the following animals most likely uses the largest percentage of its energy
budget for homeostatic regulation?
A) a marine jelly (an invertebrate) living deep in the ocean
B) a snake in a tropical forest
C) a shark swimming in the open ocean
D) a bird living year round in a desert
GTPase activity is important in the regulation of signal transduction because it _____.
A) increases the available concentration of phosphate
B) decreases the amount of G protein in the membrane
C) hydrolyzes GTP to GDP, thus shutting down the pathway
D) converts cGMP to GTP
One possible result of chromosomal breakage is for a fragment to join a
nonhomologous chromosome. What is this alteration called?
A) deletion
B) inversion
C) translocation
D) duplication
After looking at the experiment in the figure above, what can be said about productivity
in marine ecosystems?
A) Nothing can be said based on this information.
B) Marine organisms break down iron for energy and thus for productivity.
C) Iron can be a limiting nutrient in productivity.
D) Productivity increases when chlorophyll a is added.
What proportion of the population is probably heterozygous (Aa) for this trait?
A) 0.05
B) 0.25
C) 0.50
D) 0.75
Which one of the following statements about transport of nutrients in phloem is correct?
A) Solute particles are actively transported from phloem at the source.
B) Companion cells control the rate and direction of movement of phloem sap.
C) Differences in osmotic concentration at the source and sink cause a hydrostatic
pressure gradient to be formed.
D) A sink is the part of a plant where a particular solute is produced.
Suppose 64% of a remote mountain village can taste phenylthiocarbamide (PTC) and
must, therefore, have at least one copy of the dominant PTC taster allele. If this
population conforms to Hardy-Weinberg expectations for this gene, what percentage of
the population must be heterozygous for this trait?
A) 16%
B) 32%
C) 40%
D) 48%
The cochlea _____.
I) amplifies sound vibrations
II) collects sound pressure waves
III) detects the frequency of sounds
A) only I
B) only II
C) only III
D) only II and III
In an experimental situation, a student researcher inserts an mRNA molecule into a
eukaryotic cell after she has removed its cap and poly-A tail. Which of the following
would you expect her to find?
A) The mRNA is quickly converted into a ribosomal subunit.
B) The cell adds a new poly-A tail to the mRNA.
C) The mRNA attaches to a ribosome and is translated, but more slowly.
D) The molecule is digested by enzymes because it is not protected at the end.