Which of the following can function in signal transduction in plants ?
I) calcium ions
II) nonrandom mutations
III) receptor proteins
IV) autochrome
V) secondary messengers
A) only I, III, and IV
B) only I, II, and V
C) only I, III, and V
D) only II, III, and V
The cities of Portland, Oregon, and Minneapolis, Minnesota, are at about the same
latitude, but Minneapolis has much hotter summers and much colder winters than
Portland. Why?
A) They are not at the same exact latitude.
B) The ocean near Portland moderates the temperature.
C) Fresh water is more likely to freeze than salt water.
D) Minneapolis is much windier, due to its location in the middle of North America.
Map units on a linkage map cannot be relied upon to calculate physical distances on a
chromosome for which of the following reasons?
A) The frequency of crossing over varies along the length of the chromosome.
B) The relationship between recombination frequency and map units is different in
every individual.
C) Physical distances between genes change during the course of the cell cycle.
D) The gene order on the chromosomes is slightly different in every individual.
Which of the following statements regarding turnover in a lake is correct?
A) In fall turnover, dense water at 4oC sinks and disturbs sediments in the benthic zone.
B) In fall turnover, dense water at 4oC rises and disturbs sediments in the benthic zone.
C) The surface water gets to 4oC only by cooling.
D) Fall turnovers and spring turnovers are exactly the same.
Nudibranchs, a type of predatory sea slug, can have various protuberances (that is,
extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to
the head, which bear many chemoreceptors. Dorsal plummules, usually located
posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal
surface and contain nematocysts at their tips.
The claws (fangs) on the foremost trunk segment of centipedes have a function most
similar to that of _____.
A) rhinophores
B) dorsal plummules
C) cerata
D) chemoreceptors
Some molecular data place the giant panda in the bear family (Ursidae) but place the
lesser panda in the raccoon family (Procyonidae). If the molecular data best reflect the
evolutionary history of these two groups, then the morphological similarities of these
two species is most likely due to _____.
A) the inheritance of acquired characteristics
B) sexual selection
C) possession of analogous (convergent) traits
D) possession of shared primitive characters
A carbon atom is most likely to form what kind of bond(s) with other atoms?
A) ionic
B) hydrogen
C) covalent
D) ionic bonds, covalent bonds, and hydrogen bonds
From earliest to latest, the overall sequence of early development proceeds in which of
the following sequences?
A) first cell division → synthesis of embryo’s DNA begins → acrosomal reaction →
cortical reaction
B) cortical reaction → synthesis of embryo’s DNA begins → acrosomal reaction → first
cell division
C) cortical reaction → acrosomal reaction → first cell division → synthesis of embryo’s
DNA begins
D) acrosomal reaction → cortical reaction → synthesis of embryo’s DNA begins → first
cell division
The questions below refer to the following evolutionary tree, in which the horizontal
axis represents time (present time is on the far right) and the vertical axis represents
morphological change.
Which conclusion can be drawn from this evolutionary tree?
A) A single clade (that is, a group of species that share a common ancestor) can include
species that formed by gradualism and other species that formed by punctuated
equilibrium.
B) A single clade (that is, a group of species that share a common ancestor) will either
include species that formed by gradualism or species that formed by punctuated
equilibrium.
C) Assuming that the tip of each line represents a species, there are five extant (that is,
not extinct) species resulting from the earliest common ancestor.
D) Species X and Z best represent species that evolved by punctuated equilibrium.
Cell size is limited by _____.
A) the number of proteins within the plasma membrane
B) the surface area of mitochondria in the cytoplasm
C) surface to volume ratios
D) the size of the endomembrane system
The figure below represents a cross section of the sea floor through a mid-ocean rift
valley, with alternating patches of black and white indicating sea floor with reversed
magnetic polarities. At the arrow labeled “I” (the rift valley), the igneous rock of the sea
floor is so young that it can be accurately dated using carbon-14 dating. At the arrow
labeled “III,” however, the igneous rock is about one million years old, and
potassium-40 dating is typically used to date such rocks. Note: The horizontal arrows
indicate the direction of sea-floor spreading, away from the rift valley.
How many other bands of sea-floor crust in the figure above have the same magnetic
polarity as the crust that directly straddles the rift valley?
A) two bands
B) four bands
C) five bands
D) eight bands
A skeletal muscle deprived of adequate ATP supplies will _____.
A) immediately relax
B) enter a state where actin and myosin are unable to separate
C) fire many more action potentials than usual and enter a state of “rigor”
D) sequester all free calcium ions into the sarcoplasmic reticulum
A lizard’s bobbing dewlap (a colorful flap of skin hanging from an Anolis lizard’s
throat) is an example of a(n) _____.
A) stimulus
B) reflex
C) signal
D) innate releasing mechanism
In deep water, which of the following abiotic factors would most limit productivity?
A) temperature
B) light availability
C) solute concentration
In extremely cold regions, woody species may survive freezing temperatures by_____.
A) emptying water from the vacuoles to prevent freezing
B) decreasing the numbers of phospholipids in cell membranes
C) decreasing the fluidity of all cellular membranes
D) increasing cytoplasmic levels of specific solute concentrations, such as sugars
Suppose an experimenter becomes proficient with a technique that allows her to move
DNA sequences within a prokaryotic genome.
If she moves the repressor gene (lacI), along with its promoter, to a position at some
several thousand base pairs away from its normal position, we would expect the _____.
A) repressor will no longer bind to the operator
B) repressor will no longer bind to the inducer
C) lac operon will be expressed continuously
D) lac operon will function normally
The citric acid cycle.
Starting with citrate, which of the following combinations of products would result
from three acetyl CoA molecules entering the citric acid cycle (see the accompanying
figure)?
A) 1 ATP, 2 CO2, 3 NADH, and 1 FADH2
B) 3 ATP, 3 CO2, 3 NADH, and 3 FADH2
C) 3 ATP, 6 CO2, 9 NADH, and 3 FADH2
D) 38 ATP, 6 CO2, 3 NADH, and 12 FADH2
The first genetic material on Earth was probably _____.
A) DNA produced by reverse transcriptase from abiotically produced RNA
B) DNA molecules whose information was transcribed to RNA and later translated in
polypeptides
C) self-replicating RNA molecules
D) oligopeptides located within protobionts
Given that phylogenies are based on shared derived characteristics, which of the
following traits is useful in generating a phylogeny of species W, X, Y, and Z?
A) Trait 1
B) Trait 2
C) Trait 3
D) Traits 1, 2, and 3
Why do adult urochordates (tunicates) lack notochords, even though larval urochordates
have them? Larvae use notochords to _____.
A) aid in swimming; adults are sessile and thus no longer propel themselves.
B) stiffen their bodies; in adults, the notochord is replaced by a column of bone.
C) induce tissue differentiation; in adults, tissue is already differentiated.
D) organize their nervous systems; adults’ nervous systems are fully developed and do
not change.
Which of these, if true, would support the claim that the ancestral cnidarians had
bilateral symmetry?
1. Cnidarian larvae possess anterior-posterior, left-right, and dorsal-ventral aspects.
2. Cnidarians have fewer Hox genes than bilaterians.
3. All extant cnidarians, including Nematostella, are diploblastic.
4. β-catenin turns out to be essential for gastrulation in all animals in which it occurs.
5. All cnidarians are acoelomate.
A) 1 and 4
B) 2 and 3
C) 2 and 4
D) 4 and 5
Which of the following mechanisms are used to regulate blood pressure in the closed
circulatory system of vertebrates?
I) changing the force of heart contraction
II) constricting and relaxing sphincters in the walls of arterioles
III) adjusting the volume of blood contained in the veins
A) only I and II
B) only I and III
C) only II and III
D) I, II, and III
The regulatory centers for the respiratory and circulatory systems are found in the
_____.
A) cerebrum
B) cerebellum
C) thalamus
D) medulla oblongata
Tissues of sharks are isotonic to seawater, but their concentrations of sodium ions,
potassium ions, and chloride ions in cells and extracellular fluids are similar to those of
freshwater fishes. What can you infer about the movement of sodium and chloride in
these animals?
A) To maintain homeostasis of sodium and chloride levels, the shark must take up
additional sodium and chloride from seawater.
B) Sodium and chloride will diffuse into shark gills from seawater down their
concentration gradient.
C) Sharks conserve sodium and chloride, limiting excretion.
D) Sodium and chloride must be eliminated through the gills.
Which of these might have been observed in the common ancestor of chondrichthyans
and osteichthyans?
A) a mineralized, bony skeleton
B) opercula
C) a spiral valve intestine
D) a swim bladder
Locating new nature preserves in biodiversity hot spots may not necessarily the best
choice because _____.
A) hot spots are situated in remote areas not accessible to the public
B) their ecological importance makes land purchase very expensive
C) a hot spot helps conserve only a few species
D) changing environmental conditions may shift the location of the communities
In seed plants, which of the following is part of a pollen grain and has a function most
like that of the seed coat?
A) sporophyll
B) sporopollenin
C) stigma
D) sporangium
Imagine five forest communities, each with one hundred individuals distributed among
four different tree species (W, X, Y, and Z). Which forest community would be most
diverse?
A) 25W, 25X, 25Y, 25Z
B) 40W, 30X, 20Y, 10Z
C) 50W, 25X, 15Y, 10Z
D) 70W, 10X, 10Y, 10Z
Which of the following statements describes chromatin?
A) Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and
RNA.
B) Both heterochromatin and euchromatin are found in the cytoplasm.
C) Heterochromatin is highly condensed, whereas euchromatin is less compact.
D) Euchromatin is not transcribed, whereas heterochromatin is transcribed.
Why does the 2009 U.S. population continue to grow even though the United States has
essentially established a zero population growth (ZPG)?
A) emigration
B) immigration
C) baby boomer reproduction
D) the 2007-2009 economic recession
The role that humans play in artificial selection is to _____.
A) determine who lives and who dies
B) create genetic diversity
C) choose which organisms reproduce
D) perform artificial insemination
Hormone X activates the cAMP second messenger system in its target cells. The
greatest response by a cell would come from _____.
A) applying a molecule of hormone X to the extracellular fluid surrounding the cell
B) injecting a molecule of hormone X into the cytoplasm of the cell
C) applying a molecule of cAMP to the extracellular fluid surrounding the cell
D) injecting a molecule of activated, cAMP-dependent protein kinase into the
cytoplasm of the cell