The reason that the steroid hormone aldosterone affects only a small number of cells in
the body is that _____.
A) only its target cells get exposed to aldosterone
B) only its target cells contain aldosterone receptors
C) it is unable to enter nontarget cells
D) nontarget cells destroy aldosterone before it can produce any effect
When a person gets dehydrated while exercising on a hot day, their pituitary gland
releases ADH, a hormone that signals the kidneys to retain more water. This is an
example of
A) Positive feedback regulation
B) Negative feedback regulation
C) Chemical cycling
D) Emergent properties
A plant has the following characteristics: a taproot system, several growth rings evident
in a cross section of the stem, and a layer of bark around the outside. Which of the
following best describes the plant?
A) herbaceous eudicot
B) woody eudicot
C) woody monocot
D) herbaceous monocot
There is still some controversy among biologists about whether Neanderthals should be
placed within the same species as modern humans or into a separate species of their
own. Most DNA sequence data analyzed so far indicate that there was probably little or
no gene flow between Neanderthals and Homo sapiens. Which species concept is most
applicable in this example?
A) phylogenetic
B) ecological
C) morphological
D) biological
Which process could have allowed the nucleomorphs of chlorarachniophytes to be
reduced, without the net loss of any genetic information?
A) conjugation
B) horizontal gene transfer
C) phagocytosis
D) meiosis
Effective antiviral drugs are usually associated with which of the following properties?
A) interference with viral replication
B) prevention of the host from becoming infected
C) removal of viral proteins
D) removal of viral mRNAs
The teacher and class were especially saddened when the colonial hydrozoan died.
They had watched it carefully, and the unfortunate creature never even got to produce
offspring by budding. Yet, everyone was elated when one of the students noticed a
small colonial hydrozoan growing in a part of the tank far from the location of the
original colony. The teacher was apparently unaware that these hydrozoans exhibit
_____.
A) spontaneous generation
B) abiogenesis
C) alternation of generations
D) a medusa stage
Which of these traits is most strongly associated with the adoption of bipedalism?
A) enhanced depth perception
B) shortened hind limbs
C) opposable big toe
D) repositioning of foramen magnum
Sperm cells are formed in plants by _____.
A) meiosis in pollen grains
B) meiosis in anthers
C) mitosis in male gametophyte
D) mitosis in the micropyle
How many electrons are involved in a single covalent bond?
A) one
B) two
C) three
D) four
Eukaryotic sexual life cycles show tremendous variation. Of the following elements,
which do all sexual life cycles have in common?
I. Alternation of generations
II. Meiosis
III. Fertilization
IV. Gametes
V. Spores
A) I, II, and IV
B) II, III, and IV
C) II, IV, and V
D) I, II, III, IV, and V
Deuteromycetes _____.
A) represent the phylum in which all the fungal components of lichens are classified
B) are the group of fungi that have, at present, no known sexual stage
C) are the group that includes molds, yeasts, and lichens
D) include the imperfect fungi that lack hyphae
The most important feature that permits a gene to act as a molecular clock is _____.
A) a large number of base pairs
B) being acted upon by natural selection
C) a reliable average rate of mutation
D) a recent origin by a gene-duplication event
The generative cell of male angiosperm gametophytes is haploid. This cell divides to
produce two haploid sperm cells. What type of cell division does the generative cell
undergo to produce these sperm cells?
A) binary fission
B) mitosis
C) meiosis
D) meiosis without subsequent cytokinesis
Sensory transduction of light in the vertebrate retina is accomplished by _____.
A) ganglion cells
B) amacrine cells
C) bipolar cells
D) rods and cones
The graph indicates that males leave the area where they were born while females stay
in the area. What is the most likely reason for the evolution of this behavior?
A) Movement of males out of the territory reduces competition for food among the
males.
B) The females are not as strong as the male ground squirrels and therefore stay closer
to their birthplace.
C) Females reproduce by parthenogenesis, which means they produce offspring from
unfertilized eggs so the males are not needed.
D) Within the ground squirrel population, males leave the area of their birth and are
replaced by new males, thus maintaining genetic diversity in the population.
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–
A recent study of ecological footprints concluded that _____.
A) Earth’s carrying capacity would increase if per capita meat consumption increased
B) current demand by industrialized countries for resources is much smaller than the
ecological footprint of those countries
C) it is not possible for technological improvements to increase Earth’s carrying
capacity for humans
D) the ecological footprint of the United States is large because per capita resource use
is high
Tubal ligation _____.
A) reduces the incidence of ovulation
B) prevents fertilization by preventing sperm from entering the uterus
C) prevents sperm from exiting the male urethra
D) prevents oocytes from entering the uterus
According to the Shannon Diversity Index, which of the five blocks above, with each
containing thirty-six squares, would show the greatest diversity?
A) 1
B) 2
C) 4
D) 5
After the depolarization phase of an action potential, the resting potential is restored by
_____.
A) the opening of voltage-gated potassium channels and the closing of sodium channels
B) a decrease in the membrane’s permeability to potassium and chloride ions
C) a brief inhibition of the sodium-potassium pump
D) the opening of more voltage-gated sodium channels
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
The sharp, inch-long thorns of the crown-of-thorns sea star are its spines. These spines,
unlike those of most other sea stars, contain a potent toxin. If it were discovered that
crown-of-thorns sea stars do not make this toxin themselves, then the most likely
alternative would be that this toxin is _____.
A) derived from the nematocysts of its prey
B) absorbed from the surrounding seawater
C) an endotoxin of cellulose-digesting bacteria that inhabit the sea star’s digestive
glands
D) injected into individual thorns by mutualistic corals which live on the aboral
surfaces of these sea stars
Which one of the atoms shown would be most likely to form an anion with a charge of
-1?
A)
B)
C)
D)
Which of the following are products of the light reactions of photosynthesis that are
utilized in the Calvin cycle?
A) CO2 and glucose
B) H2O and O2
C) ADP, i, and NADP+
D) ATP and NADPH
How many of these species probably have a cell wall that consists partly of an outer
membrane of lipopolysaccharide?
A) only one species
B) two species
C) three species
D) four species
In humans, identical twins are possible because _____.
A) cytoplasmic determinants are distributed unevenly in unfertilized eggs
B) extraembryonic cells interact with the zygote nucleus
C) early blastomeres can form a complete embryo if isolated
D) the gray crescent divides the dorsal-ventral axis into new cells
The closest relatives of the familiar pine and spruce trees are _____.
A) ferns, horsetails, lycophytes, and club mosses
B) hornworts, liverworts, and mosses
C) gnetophytes, cycads, and ginkgos
D) elms, maples, and aspens
In E. coli, there is a mutation in a gene called dnaB that alters the helicase that normally
acts at the origin. Which of the following would you expect as a result of this mutation?
A) Additional proofreading will occur.
B) No replication fork will be formed.
C) Replication will occur via RNA polymerase alone.
D) Replication will require a DNA template from another source.
Leaf thickness represents a trade-off between _____.
A) light collection and carbon dioxide absorption
B) water retention and carbon dioxide absorption
C) water retention and oxygen absorption
D) light collection and oxygenabsorption
Jams, jellies, preserves, honey, and other foods with high sugar content hardly ever
become contaminated by bacteria, even when the food containers are left open at room
temperature. This is because bacteria that encounter such an environment ____.
A) undergo death as a result of water loss from the cell
B) are unable to metabolize the glucose or fructose, and thus starve to death
C) are obligate anaerobes
D) are unable to swim through these thick and viscous materials