Which of the following statements regarding fins on fishes is true?
A) Fins evolved so that fish could swim better.
B) Fins came about because animals couldn’t live in water without them.
C) Fins are an adaptation that aid in swimming.
D) Fins resulted from a mutation caused by a movement from land to water.
Based on Acanthostega fossils, scientists now believe that the earliest tetrapods
A) were fully terrestrial.
B) were amphibians that used their limbs to drag themselves over the land from one
water hole to another.
C) were fish that used their limbs to raise themselves out of the water to get gulps of air
for oxygen.
D) were reptiles that resembled crocodiles.
A nutrition facts label from a fortified cereal states that in a single serving of cereal
there is 8% of the percent daily value of the element phosphorous. The label also says
that a single serving of cereal plus one-half cup of skim milk has 20% of the percent
daily value of phosphorus. Which of the following statements is false?
A) A half-cup of skim milk contains 12% of the percent daily value of phosphorus.
B) A half-cup of skim milk contains twice as much phosphorus as a serving of cereal.
C) Eating five servings of cereal and two and a half cups of skim milk will give you
100% of the phosphorus that you need for one day.
D) The amount of phosphorus in six servings of cereal is equal to the amount of
phosphorus in two cups of skim milk.
Where is chlorophyll found in a plant cell?
A) stroma
B) thylakoid membranes
C) cytoplasm
D) cristae
During cell reproduction, chromatin fibers coil up into structures called
A) ribosomes.
B) lysosomes.
C) chromosomes.
D) nucleoli.
Which bird adaptation is probably less well-developed in flightless birds such as
penguins and ostriches?
A) honeycombed bone structure
B) amniotic egg
C) vertebrae
D) presence of feathers
Which of the following would most quickly be eliminated by natural selection?
A) a harmful allele in an asexual, haploid population
B) a harmful recessive allele in a sexual, diploid population
C) a harmful recessive allele in a sexual, polyploid population
D) any harmful allele, regardless of the system of inheritance in a population
How will a lower ocean pH caused by ocean acidification affect coral reefs?
A) Coral reefs will grow faster because there are more carbonate ions available.
B) Coral reefs will grow slower because there are fewer carbonate ions available.
C) Coral reefs will grow faster because there are more bicarbonate ions available.
D) Coral reefs will grow slower because there are fewer bicarbonate ions available.
A transgenic animal is
A) an animal that is the first of its kind to bear a particular allele.
B) an animal in which a genetic defect has been corrected using recombinant DNA
therapy.
C) an animal containing a gene from another organism, typically of another species.
D) an animal containing genes from three or more species.
Many physiological conditions are related to particular proteins in cell membranes. The
number of insulin receptors in membranes is related to the amount of insulin present
around those cells. If the presence of increased insulin results in a decrease in receptors
and a decrease in insulin results in an increase in insulin receptors, this would be an
example of
A) a metabolic pathway.
B) negative or regulatory feedback.
C) passive transport.
D) competitive inhibition.
Which of the following statements about the humors of the eye is true?
A) The vitreous humor fills the chamber behind the lens.
B) The vitreous humor circulates.
C) The aqueous humor is jellylike.
D) The humors help keep the outside of the eye moist.
A drug that interferes with microtubule formation is likely to completely disrupt
A) the amoeboid motion of a cell.
B) the function of lysosomes.
C) contraction of muscle cells.
D) the movements of sperm cells.
The use of cloning to produce special embryonic stem cells is called
A) regenerative cloning.
B) transplantational cloning.
C) reproductive cloning.
D) therapeutic cloning.
In biological systems, an important enzyme involved in the regulation of redox
reactions is
A) glucose.
B) dehydrogenase.
C) oxygen.
D) ATP.
During ventricular systole, the _______ valves ________.
A) AV; open
B) semilunar; close
C) semilunar; open
D) AV and semilunar; close
The coding regions of a gene are called
A) introns.
B) exons.
C) promoters.
D) enhancers.
Which of the following statements is not an example of evolution that has resulted from
human activity?
A) Many strains of bacteria are now resistant to some commonly used antibiotics.
B) Like certain other crops, domesticated strawberries are larger than wild strawberries.
C) Because of hunting, organisms such as bears and wolves are fewer in number.
D) Some insect species are now resistant to pesticides.
Below are three statements. Classify them as examples of independent orientation,
crossing over, or random fertilization.
I: The formation of a zygote from an egg and a sperm is an unpredictable event.
II: Random combinations of paternal and maternal chromosomes end up in gametes.
III: An allele on the paternal chromosome 18 ends up on the maternal chromosome 18.
A) I: random fertilization; II: random fertilization; III: independent orientation
B) I: random fertilization; II: crossing over; III: independent orientation
C) I: independent orientation; II: random fertilization; III: crossing over
D) I: random fertilization; II: independent orientation; III: crossing over
Which of the following characteristics of protein will remain intact if the protein is
denatured?
A) the shape of the protein
B) the function of the protein
C) the number of amino acids in the protein
D) the binding properties of the protein
A pharmaceutical company hires a chemist to analyze the purity of the water being used
in its drug preparations. If the water is pure, the chemist would expect to find
A) only molecules of H2O.
B) H2O molecules and H+ ions.
C) H2O molecules, H+ ions, and OH– ions.
D) only H+ ions and OH– ions.
Suppose a species of wild boar (a type of pig) is actively hunted when it is at a young
age because at that stage of its development the meat of the boar is particularly tender.
What is a likely outcome if this species is overharvested?
A) The wild boar population will dwindle because their food source will disappear due
to habitat loss.
B) The wild boar population will increase because older boars will continue to survive.
C) The wild boar population will dwindle and potentially go extinct if not enough boars
that can reproduce are left to mate.
D) The wild boar population will increase because boundaries will help separate boars
from humans.
Ancestral diploid wheat species had 2n = 14 chromosomes. What happened when two
of these species hybridized?
A) They produced a viable, fertile hybrid species with 14 chromosomes.
B) They produced a hybrid species that could not complete mitosis, so it did not
develop properly.
C) They produced a hybrid species with 14 chromosomes that was sterile because the
chromosomes from the two different parent species did not pair up properly in meiosis.
D) They produced a hybrid species with 28 chromosomes.
During transmission across a typical chemical synapse,
A) neurotransmitter molecules are stored in the synaptic cleft.
B) action potentials trigger chemical changes that make the synaptic vesicles fuse with
each other.
C) vesicles containing neurotransmitters diffuse to the receiving cell’s plasma
membrane.
D) neurotransmitter molecules bind to receptors in the receiving cell’s plasma
membrane.
A Type I survivorship curve is associated with which of the following life history traits?
A) parents providing extended care for their young
B) large numbers of offspring being produced
C) infant mortality being much greater than adult mortality
D) a short life span for most individuals
Once an action potential is triggered, there is a
A) reversal of the membrane polarity, with the interior of the cell becoming positively
charged.
B) reversal of the membrane polarity, with the interior of the cell becoming negatively
charged.
C) sudden rush of potassium into the neuron.
D) sudden impermeability of the membrane to the transport of ions.
A patient visits her doctor complaining of stomach cramps, vomiting, and nausea. When
he takes a bacterial sample, he determines that Escherichia coli bacteria have used their
________ to attach to the cells lining her gastrointestinal tract.
A) cilia
B) flagella
C) fimbriae
D) peptidoglycan
Restriction enzymes specifically recognize and cut short sequences of DNA called
A) introns.
B) exons.
C) sticky ends.
D) restriction sites.
Mendel conducted his most memorable experiments on
A) peas.
B) roses.
C) guinea pigs.
D) fruit flies.
The number of species in a community is called the
A) species diversity.
B) species richness.
C) species population.
D) species index.
Scientists believe that a major factor promoting the adaptive radiation of mammals was
probably
A) their development of fur.
B) the mass extinction of most dinosaurs, an event that opened up new ecological
opportunities.
C) internal fertilization.
D) the origin and diversification of flowering plants.
Sieve-tube elements are plant cells that are part of a plant tissue called
A) xylem.
B) tracheids.
C) phloem.
D) sclereids.
Why do the two parts of the graph marked with arrows look identical?
A) They represent the depolarization and repolarization of the membrane.
B) They represent the minimum change in the membrane’s voltage that must occur to
generate and complete the action potential.
C) They represent the stimulus that begins and ends the action potential.
D) They represent the resting potential before and after the action potential has
occurred.
Transcription factors attach to
A) DNA.
B) signal molecules.
C) plasma membrane receptors.
D) mRNA.