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Why is it so important to be able to amplify DNA fragments when studying genes?
A) Before amplification, DNA fragments are likely to bind to RNA and no longer be
able to be analyzed.
B) A gene may represent only a millionth of the cell's DNA.
C) Restriction enzymes (endonucleases) cut DNA into fragments that are too small.
D) A clone requires multiple copies of each gene per clone.
If, during protein starvation, the osmotic pressure on the venous side of capillary beds
drops below the hydrostatic pressure, then _____.
A) hemoglobin will not release oxygen
B) fluids will tend to accumulate in tissues
C) the pH of the interstitial fluids will increase
D) plasma proteins will escape through the endothelium of the capillaries
Which of the following describes the most likely order of events in allopatric
speciation?
A) genetic drift, genetic isolation, divergence
B) genetic isolation, divergence, genetic drift
C) divergence, genetic drift, genetic isolation
D) genetic isolation, genetic drift, divergence
In areas of permafrost, stands of black spruce are frequently observed in the landscape,
while other tree species are noticeably absent. Often these stands are referred to as
"drunken forests" because many of the black spruce are displaced from their normal
vertical alignment. What is the most likely explanation for the unusual growth of these
forests in this marginal habitat?
A) Branches are adapted to absorb more carbon dioxide with this displaced alignment.
B) Taproot formation is impossible, so trees developed shallow root beds.
C) Trees are tilted so snow prevents them from breaking or tipping over.
D) Trees tip so that they do not compete with each other for sunlight.
If a bacterium regenerates from an endospore that did not possess any of the plasmids
that were contained in its original parent cell, the regenerated bacterium will probably
also _____.
A) lack antibiotic-resistant genes
B) lack a cell wall
C) lack a chromosome
D) lack water in its cytoplasm
Cattle are able to survive on a diet consisting almost entirely of plant material because
cattle _____.
A) are autotrophic
B) re-ingest their feces
C) manufacture all fifteen amino acids out of sugars in the liver
D) have cellulose-digesting, symbiotic microorganisms in chambers of their stomachs
Girdling is a procedure to kill unwanted tress by cutting a groove into the bark of the
tree. The groove must completely encircle the trunk and should penetrate into the wood
to a depth of at least -inch on small trees, and 1- inches on larger trees. Why does
this procedure cause tree death?
A) No water can be transported from the roots to the leaves.
B) No water can be transported from the leaves to the roots.
C) No sugars can be transported from the leaves to the roots.
D) Both water and sugars are prevented from being transported.
You have isolated a previously unstudied protein, identified its complete structure in
detail, and determined that it catalyzes the breakdown of a large substrate. You notice it
has two binding sites. One of these is large, apparently the bonding site for the large
substrate; the other is small, possibly a binding site for a regulatory molecule. What do
these findings tell you about the mechanism of this protein?
A) It is probably a structural protein that is involved in cell-to-cell adhesion.
B) It is probably an enzyme that works through allosteric regulation.
C) It is probably an enzyme that works through competitive inhibition.
D) It is probably a cell membrane transport protein"like an ion channel.
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.
Which structure do sea slugs use to feed on their prey?
A) nematocysts
B) an incurrent siphon
C) a radula
D) a mantle cavity
As the size of some animals has evolved to greater sizes, the effectiveness of their
adaptations that promote exchanges with the environment have also increased. For
example, in many larger organisms, evolution has favored lungs and a digestive tract
with _____.
A) more branching or folds
B) increased thickness
C) larger cells
D) decreased blood supply
On a submarine expedition to the ocean bottom, you discover a population of fish that
are only female. What type of reproduction does this fish most likely use?
A) sexual
B) budding
C) cloning
D) parthenogenesis
You have before you a living organism, which you examine carefully. Which of the
following should convince you that the organism is acoelomate?
A) It is triploblastic.
B) It has bilateral symmetry.
C) It possesses sensory structures at its anterior end.
D) Muscular activity of its digestive system distorts the body wall.
Why are C4 plants able to photosynthesize with no apparent photorespiration?
A) They do not participate in the Calvin cycle.
B) They use PEP carboxylase to initially fix CO2.
C) They conserve water more efficiently.
D) They exclude oxygen from their tissues.
In humans, the embryonic and fetal forms of hemoglobin have a higher affinity for
oxygen than that of adults. This is due to _____.
A) nonidentical genes that produce different versions of globins during development.
B) pseudogenes, which interfere with gene expression in adults.
C) the attachment of methyl groups to cytosine following birth, which changes the type
of hemoglobin produced.
D) histone proteins changing shape during embryonic development.
A graded hyperpolarization of a membrane can be induced by _____.
A) increasing its membrane's permeability to Na+
B) decreasing its membrane's permeability to Cl-
C) increasing its membrane's permeability to Ca++
D) increasing its membrane's permeability to K+
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the
frequency of allele a is 0.1. What is the frequency of individuals with AA genotype?
A) 0.20
B) 0.32
C) 0.42
D) 0.81
Which of the following occur during the formation of an embryo from a zygote in
angiosperms?
I) The root and shoot systems emerge from the seed.
II) Basal cells form a connection between the parent plant and the developing embryo.
III) Meiosis produces a mass of cells that become the young embryo.
IV) Cells differentiate to form the basic plant tissue types.
V) The early root-shoot axis is formed.
A) I, II, and III
B) II, IV, and V
C) II, III, IV, and V
D) III, IV, and V
People with type II diabetes mellitus have defective insulin receptors that cannot
respond to insulin properly. Relative to normal individuals, what would be the effect on
blood glucose levels under conditions of chronic stress that kept blood cortisol levels
high? There would be _____.
A) a greater increase in blood glucose levels in individuals with type II diabetes
mellitus than in normal individuals
B) less increase in blood glucose levels in individuals with type II diabetes mellitus
than in normal individuals
C) be a greater decrease in blood glucose levels in individuals with type II diabetes
mellitus than in normal individuals
D) less decrease in blood glucose levels in individuals with type II diabetes mellitus
than in normal individuals
Starting with a fertilized egg (zygote), a series of five cell divisions would produce an
early embryo with how many cells?
A) 8
B) 16
C) 32
D) 64
Rose-picker's disease is caused by the yeast Sporothrix schenkii (S. schenkii). The yeast
grows on the exteriors of rose-bush thorns. If a human gets pricked by such a thorn, the
yeasts can be introduced under the skin. The yeasts then assume a hyphal morphology
and grow along the interiors of lymphatic vessels until they reach a lymph node. This
often results in the accumulation of pus in the lymph node, which subsequently
ulcerates through the skin surface and then drains.
The answer to which of these questions would be of most assistance to one who is
attempting to assign the genus Sporothrix to the correct fungal phylum?
A) Do these yeasts perform fermentation while growing on the rose-bush thorns, or do
they wait until inside a human host?
B) Does S. schenkii rely on animal infection to complete some part of its life cycle, or is
the infection merely opportunistic?
C) Are the hyphae in lymphatic vessels septate, or are they coenocytic?
D) Is S. schenkii best described as a decomposer, parasite, pathogen, or mutualist of
humans?
What is the most logical sequence of steps for splicing foreign DNA into a plasmid and
inserting the plasmid into a bacterium?
I. Transform bacteria with a recombinant DNA molecule.
II. Cut the plasmid DNA using restriction enzymes (endonucleases).
III. Extract plasmid DNA from bacterial cells.
IV. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments.
V. Use ligase to seal plasmid DNA to nonplasmid DNA.
A) II, III, V, IV, I
B) III, II, IV, V, I
C) III, IV, V, I, II
D) IV, V, I, II, III
The receptors for steroid hormones are located inside the cell instead of on the
membrane surface like most other signal receptors. This is not a problem for steroids
because _____.
A) the receptors can be readily stimulated to exit and relocate on the membrane surface
B) steroids do not directly affect cells but instead alter the chemistry of blood plasma
C) steroid hormones are lipid soluble, so they can readily diffuse through the lipid
bilayer of the cell membrane
D) steroids must first bond to a steroid activator, forming a complex that then binds to
the cell surface
Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all
cells but affect only target cells because _____.
A) only target cells retain the appropriate DNA segments
B) intracellular receptors are present only in target cells
C) only target cells possess the cytosolic enzymes that transduce the testosterone
D) only in target cells is testosterone able to initiate the phosphorylation cascade
leading to activated transcription factor
A primary reason that the kidneys have one of the highest metabolic rates of all body
organs is that _____.
A) they have membranes of varying permeability to water
B) they operate an extensive set of active-transport ion pumps
C) they are the body's only means of shedding excess nutrients
D) they have an abundance of myogenic smooth muscle
When the air in a testing chamber is specially mixed so that its oxygen content is 10
percent and its overall air pressure is 400 mm Hg, then is _____.
A) 400 mm Hg
B) 82 mm Hg
C) 40 mm Hg
D) 4 mm Hg
Besides oil, what other chemical should be detected in substantial amounts upon
chemical analysis of these small spheres?
A) sporopollenins
B) phenolics
C) waxes
D) terpenes
A population of viruses with similar characteristics is called a _____.
A) strain
B) species
C) type
D) genome
The force driving simple diffusion is _____, while the energy source for active transport
is _____.
A) the concentration gradient; ADP
B) the concentration gradient; ATP
C) transmembrane pumps; electron transport
D) phosphorylated protein carriers; ATP
Which of the following is characteristic of the lytic cycle?
A) Viral DNA is incorporated into the host genome.
B) The viral genome replicates without destroying the host.
C) A large number of phages are released at a time.
D) The virushost relationship usually lasts for generations.
A male's "primary" sex characteristics include _____.
A) deepening of the voice at puberty
B) development of the seminal vesicles and associated ducts
C) elongation of the skeleton prior to puberty
D) onset of growth of facial hair at puberty
Let us suppose that someone is successful at producing induced pluripotent stem cells
(iPS) for replacement of pancreatic insulin-producing cells for people with type 1
diabetes. Which of the following could still be problems?
I. the possibility that, once introduced into the patient, the iPS cells produce
nonpancreatic cells
II. the failure of the iPS cells to take up residence in the pancreas
III. the inability of the iPS cells to respond to appropriate regulatory signals
A) I only
B) II only
C) III only
D) I, II, and III
A team of researchers has developed a poison that has proven effective against lamprey
larvae in freshwater cultures. The poison is ingested and causes paralysis by detaching
segmental muscles from the skeletal elements. The team wants to test the poison's
effectiveness in streams feeding Lake Michigan, but one critic worries about potential
effects on lancelets, which are similar to lampreys in many ways. Why is this concern
misplaced?
A) Lamprey larvae and lancelets have very different feeding mechanisms.
B) Lancelets do not have segmental muscles.
C) Lancelets live only in saltwater environments.
D) Lancelets and lamprey larvae eat different kinds of food.
