One of the buffers that contribute to pH stability in human blood is carbonic acid
(H2CO3). Carbonic acid is a weak acid that, when placed in an aqueous solution,
dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+), as noted below.
If the pH of blood increases, one would expect _____.
A) a decrease in the concentration of H2CO3 and an increase in the concentration of
HCO3–
B) an increase in the concentration of H2CO3 and a decrease in the concentration of
HCO3–
C) a decrease in the concentration of HCO3– and an increase in the concentration of H+
D) an increase in the concentration of HCO3– and a decrease in the concentration of
OH-
The main source of water necessary for photosynthesis to occur in the leaf mesophyll is
_____.
A) soil via the xylem
B) soil via the phloem
C) the atmosphere through the cuticle and stomata
D) all of the listed responses
In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the
production of _____.
A) ATP, CO2, and ethanol (ethyl alcohol)
B) ATP, CO2, and lactate
C) ATP, NADH, and pyruvate
D) ATP, pyruvate, and acetyl CoA
Organisms maintain dynamic homeostasis (internal balance) through behavioral and
physiological mechanisms. Which of the following statements is an accurate
explanation of a negative feedback mechanism used by animals to regulate body
temperature?
A) Squirrels are able to cool themselves during warmer months by producing more
brown fat, which contains abundant mitochondria and a rich blood supply.
B) Desert jackrabbits have unusually large ears that serve as solar heat collectors to
enable them to maintain their body temperatures.
C) A ground squirrel’s hypothalamus detects changes in environmental temperatures
and responds by activating or suppressing metabolic heat production.
D) A goldfish slows its movements when the water temperature is lower.
According to the logistic growth equation, = rmaxN,
A) the number of individuals added per unit time is greatest when N is close to zero.
B) the per capita growth rate (r) increases as N approaches K.
C) population growth is zero when N equals K.
D) the population grows exponentially when K is small.
What is the difference between an aldose sugar and a ketose sugar?
A) the number of carbons
B) the position of the hydroxyl groups
C) the position of the carbonyl group
D) One is a ring form, the other is a linear chain/
_____ prevents seeds from germinating until conditions are favorable for the growth of
the plant.
A) Ethylene
B) Zeaxanthin
C) Gibberellin
D) Abscisic acid
Wakefulness is regulated by the reticular formation, which is present in the _____.
A) basal nuclei
B) cerebral cortex
C) brainstem
D) limbic system
The active site of an enzyme is the region that _____.
A) binds allosteric regulators of the enzyme
B) is involved in the catalytic reaction of the enzyme
C) binds noncompetitive inhibitors of the enzyme
D) is inhibited by the presence of a coenzyme or a cofactor
The lock-and-key analogy for enzymes applies to the specificity of enzymes _____.
A) as they form their tertiary and quaternary structure
B) binding to their substrate
C) interacting with water
D) interacting with ions
Which pair correctly associates a physiological process with the appropriate vitamin?
A) blood clotting vitamin C
B) normal vision vitamin A
C) synthesis of cell membranes vitamin D
D) production of white blood cells vitamin K
In the phylogenetic trees above, numbers represent species and the same species are
shown in both trees. Which two species are represented as sister species in Tree 2 but
are not shown as sister species in Tree 1?
A) 1 and 2
B) 2 and 3
C) 3 and 4
D) 4 and 5
If the sun were to suddenly stop providing energy to Earth, most ecosystems would
vanish. Which of the following ecosystems would likely survive the longest after this
hypothetical disaster?
A) tropical rain forest
B) tundra
C) benthic ocean
D) desert
Which of the following is true of carbon?
A) It forms only polar molecules.
B) It can form a maximum of three covalent bonds with other elements.
C) It is highly electronegative.
D) It can form both polar and nonpolar bonds.
The electron transport chain _____.
A) is a series of redox reactions
B) is a series of substitution reactions
C) is driven by ATP consumption
D) takes place in the cytoplasm of prokaryotic cells
Water has many exceptional and useful properties. Which is the rarest property among
compounds?
A) Water is a solvent.
B) Solid water is less dense than liquid water.
C) Water has a high heat capacity.
D) Water has surface tension.
Proto-oncogenes _____.
A) normally suppress tumor growth
B) are produced by somatic mutations induced by carcinogenic substances
C) stimulate normal cell growth and division
D) are underexpressed in cancer cells
Organisms share many conserved core processes and features, including transcription
and translation using a uniform genetic code. Scientists have used these shared
processes and features in biotechnology. For example, for the process of some
transformations, a plasmid is constructed when a eukaryotic gene of interest is added
with an antibiotic resistant gene such beta-lactamase, which is used for ampicillin
resistance. This plasmid is then inserted into a prokaryotic bacterial cell, such as E-coli,
through a transformation process that leads to the production of the product protein
from the eukaryotic organism. To culture the bacteria and obtain the protein product, the
bacteria must grow.
Select the appropriate condition to determine if the plasmid has entered the E-coli
bacterial cell.
A) Nutrient broth to which no antibiotic has been added.
B) Water to which ampicillin has been added.
C) Nutrient broth to which ampicillin has been added.
D) Nutrient broth to which other resistant bacteria have been added.
The following questions refer to the pedigree chart in the figure below for a family,
some of whose members exhibit the dominant trait, W. Affected individuals are
indicated by a dark square or circle.
What is the genotype of individual II-5?
A) WW
B) Ww
C) ww
D) ww or Ww
Which of the following is a fitness trade-off (compromise)?
A) In some hornbill species, the male helps seal the female in a tree with her nest until
the young are ready to fledge.
B) Hummingbirds are the best pollinators of certain flowers, but bees are the best
pollinators for orchids.
C) The strong, thick beak of a woodpecker helps it find insects in trees.
D) Turtle shells provide protection but are heavy and burdensome when moving.
Living organisms increase in complexity as they grow, resulting in a decrease in the
entropy of an organism. How does this relate to the second law of thermodynamics?
A) Living organisms do not obey the second law of thermodynamics, which states that
entropy must increase with time.
B) Life obeys the second law of thermodynamics because the decrease in entropy as the
organism grows is exactly balanced by an increase in the entropy of the universe.
C) As a consequence of growing, organisms cause a greater increase in entropy in their
environment than the decrease in entropy associated with their growth.
D) Living organisms are able to transform energy into entropy.
Which of the following best substantiates why location 3 is an equatorial (tropical)
climate?
A) It has a monsoon season during the winter months.
B) The temperature is high for each monthly average.
C) The temperatures reach 100F during some months.
D) The temperatures are lower in June, July, and August.
How does the enzyme telomerase meet the challenge of replicating the ends of linear
chromosomes?
A) It adds a single cap structure that resists degradation by nucleases.
B) It causes specific double-strand DNA breaks that result in blunt ends on both strands.
C) It catalyzes the lengthening of telomeres, compensating for the shortening that could
occur during replication without telomerase activity.
D) It adds numerous GC pairs, which resist hydrolysis and maintain chromosome
integrity.
Of the following human aneuploidies, which is the one that generally has the most
severe impact on the health of the individual?
A) 47, trisomy 21
B) 47, XXY
C) 47, XXX
D) 45, X
If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps
involving humans, starting from phytoplankton to zooplankton to fish to seals to polar
bears, then which of the following could be true?
A) Polar bears can provide more food for humans than seals can.
B) The total biomass of the fish is lower than that of the seals.
C) Seal populations are larger than fish populations.
D) Fish can potentially provide more food for humans than seal meat.
In a bacterium, we will find DNA in _____.
A) a membrane-enclosed nucleus
B) mitochondria
C) the nucleoid
D) ribosomes
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.
The phenomenon of fusion is likely to occur when, after a period of geographic
isolation, two populations meet again and _____.
A) an increasing number of infertile hybrids is produced over the course of the next one
hundred generations
B) no reproduction occurs in the hybrid zone
C) an increasing number of viable, fertile hybrids is produced over the course of the
next one hundred generations
D) a decreasing number of viable, fertile hybrids is produced over the course of the next
one hundred generations
One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 liter of a
solution of pH 6?
A) 4 times more
B) 40,000 times more
C) 10,000 times more
D) 100,000 times more
A researcher lyses a cell that contains nucleic acid molecules and capsomeres of
tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight.
The next day this mixture is sprayed on tobacco plants. We expect that the plants would
_____.
A) develop some but not all of the symptoms of the TMV infection
B) develop the typical symptoms of TMV infection
C) not show any disease symptoms
D) become infected, but the sap from these plants would be unable to infect other plants
Neurotransmitters are released from axon terminals via _____.
A) osmosis
B) active transport
C) diffusion
D) exocytosis