Which of the following would be the most effective strategy to remove toxic heavy
metals from a soil?
A) heavy irrigation to leach out the heavy metals
B) application of sulfur to lower the soil pH and precipitate the heavy metals
C) adding plant species that have the ability to take up and accumulate heavy metals
D) inoculating soil with mycorrhizae to avoid heavy-metal uptake
Molybdenum has an atomic number of 42. Several common isotopes exist, with mass
numbers from 92-100. Therefore, which of the following can be true?
A) Molybdenum atoms can have between 50 and 58 neutrons.
B) Molybdenum atoms can have between 50 and 58 protons.
C) Molybdenum atoms can have between 50 and 58 electrons.
D) Isotopes of molybdenum have different numbers of electrons.
Nucleic acids are polymers made up of which of the following monomers?
A) nucleotides
B) sugars
C) amino acids
D) nitrogenous bases
Which statements about K are correct?
I) K varies among populations.
II) K varies in space.
III) K varies in time.
IV) K is constant for any given species.
A) only I and III
B) only II and IV
C) only I, II, and III
D) only II, III, and IV
In the late 1950s, Meselson and Stahl grew bacteria in a medium containing “heavy”
nitrogen (15N) and then transferred them to a medium containing 14N. Which of the
results in the figure above would be expected after one round of DNA replication in the
presence of 14N?
A) A
B) B
C) C
D) D
Which of the following could be considered the most recent common ancestor of living
tetrapods?
A) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports
similar to those of terrestrial vertebrates
B) an armored, jawed placoderm with two pairs of appendages
C) an early ray-finned fish that developed bony skeletal supports in its paired fins
D) a salamander that had legs supported by a bony skeleton but moved with the
side-to-side bending typical of fishes
Two fundamental concepts about the ion channels of a “resting” neuron are that the
channels _____.
A) are always open, but the concentration gradients of ions frequently change
B) are always closed, but ions move closer to the channels during excitation
C) open and close depending on stimuli, and are specific as to which ion can traverse
them
D) open in response to stimuli, and then close simultaneously, in unison
To introduce a particular piece of DNA into an animal cell, such as that of a mouse, you
would most likely be successful with which of the following methods?
A) electroporation followed by recombination
B) introducing a plasmid into the cell
C) infecting the mouse cell with a Ti plasmid
D) transcription and translation
Injury localized to the hypothalamus would most likely disrupt _____.
A) short-term memory
B) coordination during locomotion
C) executive functions, such as decision making
D) regulation of body temperature
Which molecules shown above contain a carbonyl group?
A) A and B
B) B and C
C) B, C, and D
D) C and D
The figure above shows a diagram of blocks of genes on human chromosome 16 and
the locations of blocks of similar genes on four chromosomes of the mouse.
The movement of these blocks suggests that _____.
A) during evolutionary time, these sequences have separated and have returned to their
original positions
B) DNA sequences within these blocks have become increasingly divergent
C) sequences represented have duplicated at least three times
D) chromosomal translocations have moved blocks of sequences to other chromosomes
Bacteria entering the body through a small cut in the skin _____.
A) inactivate the erythrocytes
B) stimulate apoptosis of nearby body cells
C) stimulate release of interferons
D) activate a group of proteins called complement
How could you increase the magnitude of inhibitory postsynaptic potentials (IPSPs)
generated at a synapse?
A) increase sodium-potassium pump activity
B) increase K+ permeability
C) increase the influx of calcium
D) All of the listed responses are correct.
A nonreciprocal crossover causes which of the following products?
A) deletion only
B) duplication only
C) nondisjunction
D) deletion and duplication
What type of signal is brief and can work among obstructions at night?
A) olfactory
B) visual
C) auditory
D) magnetic
What is the function of the nuclear pore complex found in eukaryotes?
A) It regulates the movement of proteins and RNAs into and out of the nucleus.
B) It synthesizes the proteins required to copy DNA and make mRNA.
C) It selectively transports molecules out of the nucleus, but prevents all inbound
molecules from entering the nucleus.
D) It assembles ribosomes from raw materials that are synthesized in the nucleus.
Jahasz-Pocsine and co-workers found a correlation between gastric bypass surgery and
neurological complications. Surgeons performed gastric bypass surgery on 150 patients
at the University of Arkansas for Medical Sciences Neurology Clinic. Of the 150
patients, 26 experienced neurological complications related to the surgery. What is the
most likely cause for the neurological complications?
A) sudden weight loss and caloric deficiency interfering with neurological function
B) nutrient (for example, vitamin and mineral) deficiencies
C) sloppy surgical technique of physicians performing the bypass surgery
D) infections following surgical intervention
The body’s automatic tendency to maintain a constant and optimal internal environment
is termed _____.
A) balanced equilibrium
B) physiological chance
C) homeostasis
D) static equilibrium
The large surface area in the gut directly facilitates _____.
A) secretion
B) absorption
C) filtration
D) temperature regulation
The earliest vascular plants on land had underground stems (rhizomes) but no roots.
Water and mineral nutrients were most likely obtained by_____.
A) diffusion through stomata
B) absorption by mycorrhizae
C) osmosis through the root hairs
D) diffusion across the cuticle of the rhizome
Plants produce more seeds when they reproduce asexually than sexually. Yet most
plants reproduce sexually in nature. What is the probable explanation for the prevalence
of sexual reproduction? Sexual reproduction _____.
A) is more energy efficient than asexual reproduction
B) ensures genetic continuity from parents to offspring
C) mixes up alleles contributing to variation in a species
D) is not dependent on other agents of pollination
Independent assortment of chromosomes is a result of _____.
A) the random way each pair of homologous chromosomes lines up at the metaphase
plate during meiosis I
B) the random combinations of eggs and sperm during fertilization
C) the random distribution of the sister chromatids to the two daughter cells during
anaphase II
D) the diverse combination of alleles that may be found within any given chromosome
The reason that paralogous genes can diverge from each other within the same gene
pool, whereas orthologous genes diverge only after gene pools are isolated from each
other, is that _____.
A) having multiple copies of genes is essential for the occurrence of sympatric
speciation in the wild
B) paralogous genes can occur only in diploid species; thus, they are absent from most
prokaryotes
C) polyploidy is a necessary precondition for the occurrence of sympatric speciation in
the wild
D) having an extra copy of a gene permits modifications to the copy without loss of the
original gene product
Reinforcement is most likely to occur when _____.
A) the environment is changing
B) hybrids have lower fitness than either parent population
C) prezygotic isolating mechanisms are in place
D) gene flow is low
Which of the following is (are) problematic when the goal is to construct phylogenies
that accurately reflect evolutionary history?
A) polyphyletic taxa
B) paraphyletic taxa
C) monophyletic taxa
D) polyphyletic taxa and paraphyletic taxa
Which of the following steps has yet to be accomplished by scientists studying the
origin of life?
A) synthesis of small RNA polymers by ribozymes
B) abiotic synthesis of polypeptides
C) formation of molecular aggregates with selectively permeable membranes
D) formation of protocells that use DNA to direct the polymerization of amino acids
Ingested dietary substances must cross cell membranes to be used by the body. This
process is known as _____.
A) ingestion
B) digestion
C) hydrolysis
D) absorption
Plant hormones _____.
A) in plant cells naturally exist in very large amounts
B) change their shape in response to stimulus
C) are unable to move from one cell to another
D) affect only cells with the appropriate receptor
Reinforced, threadlike pseudopods that can perform phagocytosis are generally
characteristic of _____.
A) forams
B) water molds
C) dinoflagellates
D) oomycetes
At which phase are centrioles beginning to move apart in animal cells?
A) anaphase
B) prometaphase
C) metaphase
D) prophase
A potassium ion gradient is set up in insect Malpighian tubules through an active
transport process. As a result, potassium concentration is higher in the lumen of the
tubules than in hemolymph. How would the potassium gradient affect water movement?
A) Water would be forced out of the lumen of the Malpighian tubules through an
osmotic gradient.
B) The potassium gradient would have no effect on water movement.
C) There would be a net movement of water into the lumen of the tubules.
D) Water would be conserved, forming a hypertonic solution in the Malpighian tubules.
A sexually reproducing animal has two unlinked genes, one for head shape (H) and one
for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in
a gamete from this organism?
A) Hh
B) HhTt
C) T
D) HT
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
Of the following, the best conclusion concerning the difference between the S phases
for beta and gamma is that _____.
A) gamma contains more DNA than beta
B) beta and gamma contain the same amount of DNA
C) beta cells reproduce asexually
D) beta is a plant cell and gamma is an animal cell
Blood is best classified as connective tissue because _____.
A) its cells are separated from each other by an extracellular matrix
B) it contains more than one type of cell
C) its cells can move from place to place
D) it is found within all the organs of the body
The following figure depicts the outline of a large fairy ring that has appeared overnight
in an open meadow, as viewed from above. The fairy ring represents the furthest
advance of this mycelium through the soil. Locations A-D are all 0.5 meters below the
soil surface.
What is the most probable location of the oldest portion of this mycelium?
A) A
B) B
C) C
D) D