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If you change the number of neutrons in an atom, you create _____.
A) a cation
B) an anion
C) an isotope
D) a different element
The cells involved in innate immunity, whose absence increases the chances of
developing malignant tumors, are _____.
A) cytotoxic T cells
B) natural killer cells
C) macrophages
D) B cells
The importance of computers and of computer software to modern cladistics is most
closely linked to advances in _____.
A) light microscopy
B) radiometric dating
C) fossil discovery techniques
D) molecular genetics
Natural selection should favor the highest proportion of juxtamedullary nephrons in
which of the following species?
A) a river otter
B) a mouse species living in a tropical rain forest
C) a mouse species living in a temperate broadleaf forest
D) a mouse species living in a desert
Refer to the figure. To identify the molecule that accepts CO2, Calvin and Benson
manipulated the carbon-fixation cycle by either cutting off CO2 or cutting off light from
cultures of photosynthetic algae. They then measured the concentrations of various
metabolites immediately following the manipulation. How would these experiments
help identify the CO2 acceptor?
A) The CO2 acceptor concentration would decrease when either the CO2 or light are cut
off.
B) The CO2 acceptor concentration would increase when either the CO2 or light are cut
off.
C) The CO2 acceptor concentration would increase when the CO2 is cut off, but
decrease when the light is cut off.
D) The CO2 acceptor concentration would decrease when the CO2 is cut off, but
increase when the light is cut off.
Mammals have Toll-like receptors (TLRs) that can recognize a kind of macromolecule
that is absent from vertebrates but present in or on certain groups of pathogens, such as
viral _____.
A) double-stranded DNA
B) double-stranded RNA
C) glycoproteins
D) phospholipids
Which criteria allow biologists to divide chemicals into macronutrients and
micronutrients?
A) molecular weight of the element or compound
B) the quantities of each required by plants
C) how they are used in metabolism
D) whether or not they are essential for plant growth
Anchorage dependence of animal cells in vitro or in vivo depends on which of the
following?
A) attachment of spindle fibers to centrioles
B) response of the cell cycle controls to signals from the plasma membrane
C) the binding of cell-surface phospholipids to those of adjoining cells
D) response of the cell cycle controls to the binding of cell-surface phospholipids
For a chemotherapeutic drug to be useful for treating cancer cells, which of the
following is most desirable?
A) It is safe enough to limit all apoptosis.
B) It does not alter metabolically active cells.
C) It interferes with cells entering G0.
D) It interferes with rapidly dividing cells.
Starting from the wild mustard Brassica oleracea, breeders have created the strains
known as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the
following statements is correct?
A) In this wild mustard, there is enough heritable variation to permit these different
varieties.
B) Heritable variation is low in wild mustardotherwise this wild strain would have
different characteristics.
C) Natural selection is rare in wild populations of wild mustard.
D) In wild mustard, most of the variation is due to differences in soil or other aspects of
the environment.
Binding of a signaling molecule to which type of receptor leads directly to a change in
the distribution of ions on opposite sides of the membrane?
A) receptor tyrosine kinase
B) G protein-coupled receptor
C) ligand-gated ion channel
D) intracellular receptor
If an atom has a charge of +1, which of the following must be true?
A) It has two more protons than neutrons.
B) It has the same number of protons as electrons.
C) It has one more electron than it does protons.
D) It has one more proton than it does electrons.
Which of the following statements is correct about biogeochemical cycling?
A) The phosphorus cycle involves the recycling of atmospheric phosphorus.
B) The phosphorus cycle involves the weathering of rocks.
C) The carbon cycle has maintained a constant atmospheric concentration of carbon
dioxide for the past million years.
D) The nitrogen cycle involves movement of diatomic nitrogen between the biotic and
abiotic components of the ecosystem.
The advantage of excreting nitrogenous wastes as urea rather than as ammonia is that
_____.
A) urea can be exchanged for Na+
B) urea is less toxic than ammonia
C) urea does not affect the osmolar gradient
D) less nitrogen is removed from the body
Ecologists often build models to depict the relationships between organisms. In such
models, an arrow is used to link two organisms in a relationship. The arrowhead is next
to the organism that is affected. If the effect is positive, the arrow is labeled with (+),
and if negative, then the label is (-). Which of the following models best illustrates the
relationship of the Brazil nut tree and the other organisms associated with it?
A)
B)
C)
D)
It has been hypothesized that fungi and plants have a mutualistic relationship because
plants make sugars available for the fungi's use. What is the best evidence in support of
this hypothesis?
A) Fungi survive better when they are associated with plants.
B) Radioactively labeled sugars produced by plants eventually show up in the fungi
with which they are associated.
C) Fungi associated with plants have the ability to undergo photosynthesis and produce
their own sugars, while those not associated with plants do not produce their own
sugars.
D) Radioactive labeling experiments show that plants pass crucial raw materials to the
fungus for manufacturing sugars.
Cells from advanced malignant tumors often have very abnormal chromosomes and an
abnormal number of chromosomes. What might explain the association between
malignant tumors and chromosomal abnormalities?
A) Cancer cells are no longer density-dependent.
B) Cancer cells are no longer anchorage-dependent.
C) Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities.
D) Transformation introduces new chromosomes into cells.
In hybrid zones where reinforcement is occurring, we should see a decline in _____.
A) gene flow between distinct gene pools
B) speciation
C) the genetic distinctness of two gene pools
D) mutation rates
Which of the following cells or tissues arise from lateral meristem activity?
A) secondary xylem
B) leaves
C) trichomes
D) tubers
Which of the following is the best description of an atom's physical structure?
A) An atom is a solid mass of material.
B) The particles that form an atom are equidistant from each other.
C) Atoms are little bubbles of space with mass concentrated at the center of the bubble.
D) Atoms are little bubbles of space with mass concentrated on the outside surface of
the bubble.
Foods can be preserved in many ways by slowing or preventing bacterial growth.
Which of these methods should be LEAST effective at inhibiting bacterial growth?
A) Refrigeration: slows bacterial metabolism and growth.
B) Closing previously opened containers: prevents more bacteria from entering, and
excludes oxygen.
C) Pickling: creates a pH at which most bacterial enzymes cannot function.
D) Canning in heavy sugar syrup: creates osmotic conditions that remove water from
most bacterial cells.
The Hox genes came to regulate each of the following. From earliest to most recent, in
what sequence did these events evolve?
1. identity and position of paired appendages in protostome embryos
2. anterior-posterior orientation of segments in protostome embryos
3. positioning of tentacles in cnidarians
4. anterior-posterior orientation in vertebrate embryos
A) 4 → 1 → 3 → 2
B) 4 → 2 → 1 → 3
C) 3 → 2 → 1 → 4
D) 3 → 4 → 1 → 2
In the ocean, on either side of the Isthmus of Panama, are thirty species of snapping
shrimp; some are shallow-water species, others are adapted to deep water. There are
fifteen species on the Pacific side and fifteen different species on the Atlantic side. The
Isthmus of Panama started rising about ten million years ago. The oceans were
completely separated by the isthmus about three million years ago.
In the following figure, the isthmus separates the Pacific Ocean on the left (side A)
from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus
is separated into five depth habitats (1-5), with 1 being the shallowest.
Which habitats should harbor snapping shrimp species with the greatest degree of
genetic divergence from each other?
A) A1 and A5
B) A1 and B5
C) A5 and B5
D) Both A1/A5 and B1/B5 should have the greatest, but equal amounts of, genetic
divergence.
Use the following diagram of five islands formed at around the same time near a
particular mainland, as well as MacArthur and Wilson's island biogeography principles,
to answer the question(s) below.
Which island would likely have the greatest species diversity?
A) A
B) C
C) D
D) E
A student encounters a pondweed which appears to be a charophyte (stonewort). Which
of the following features would help the student determine whether the sample comes
from a charophyte or from some other type of green alga?
1. molecular structure of enzymes inside the chloroplasts
2. structure of sperm cells
3. presence of phragmoplasts
4. rings of cellulose-synthesizing complexes
A) 1 and 3
B) 1 and 4
C) 2 and 3
D) 2, 3, and 4
In eukaryotes there are several different types of RNA polymerase. Which type is
involved in transcription of mRNA for a globin protein?
A) RNA polymerase I
B) RNA polymerase II
C) RNA polymerase III
D) primase
When hydrogen ions are pumped from the mitochondrial matrix across the inner
membrane and into the intermembrane space, the result is the _____.
A) formation of ATP
B) reduction of NAD+
C) creation of a proton-motive force
D) lowering of pH in the mitochondrial matrix
Which of the groups shown above is a functional group that helps stabilize proteins by
forming covalent cross-links within or between protein molecules?
A) A
B) B
C) C
D) D
Choose the correct match of glial cell type and function.
A) astrocytes metabolize neurotransmitters and modulate synaptic effectiveness
B) oligodendrocytes produce the myelin sheaths of myelinated neurons in the peripheral
nervous system
C) radial glia the source of immunoprotection against pathogens
D) Schwann cells provide nutritional support to non-myelinated neurons
Which of the following is a correct statement about sugar movement in phloem?
A) Diffusion can account for the observed rates of transport.
B) Movement can occur both upward and downward in the plant.
C) Sugar is translocated from sinks to sources.
D) Only phloem cells with nuclei can perform sugar movement.
A man who is an achondroplastic dwarf with normal vision marries a color-blind
woman of normal height. The man's father was six feet tall, and both the woman's
parents were of average height. Achondroplastic dwarfism is autosomal dominant, and
red-green color blindness is X-linked recessive. What proportion of their sons would be
color-blind and of normal height?
A) none
B) half
C) one out of four
D) all
Which of these conditions are always true of populations evolving due to natural
selection?
Condition 1: The population must vary in traits that are heritable.
Condition 2: Some heritable traits must increase reproductive success.
Condition 3: Individuals pass on most traits that they acquire during their lifetime.
A) Condition 1 only
B) Condition 2 only
C) Conditions 1 and 2
D) Conditions 2 and 3
Scarlet gilia (Ipomopsis aggregata) usually has red flowers in an inflorescence of up to
250 flowers. In certain populations in the Arizona mountains, however, the flowers
range from red to pink to white. In early summer, most of the flowers were red. Six to
eight weeks later, the same individual plants were still present; the flowers ranged from
pink to white, and few red flowers were present. The major pollinators early in the
season were two species of hummingbirds active during the day; they emigrated to
lower elevations, and the major pollinator later in the season was a hawk moth (a type
of moth). The hawk moth was most active at sunset and later, and it preferred light pink
to white flowers after dark. When hummingbirds were present, more red flowers than
white flowers produced fruit. When only hawk moths were present, more white flowers
produced fruit (K. N. Paige and T. G. Whitham. 1985. Individual and population shifts
in flower color by scarlet gilia: A mechanism for pollinator tracking. Science
227:315-17).
Refer to the paragraph on scarlet gilia. What is the significance of measuring fruit
production?
A) It is a measure of pollination success.
B) It is a measure of seed dispersal success.
C) It is easier than counting flowers.
D) It is an indication of predation on the seeds of the plants.
The egg of a plant has a haploid chromosome number of 12 (n = 12). What is true about
the number of chromosomes in the cells of other tissues of this plant?
A) The sperm has 6 chromosomes.
B) The leaves and stems have 12 chromosomes.
C) The zygote has 12 chromosomes.
D) The endosperm has 36 chromosomes.
The most ancient branch point in animal phylogeny is the characteristic of having
_____.
A) radial or bilateral symmetry
B) diploblastic or triploblastic embryos
C) true tissues or no tissues
D) a body cavity or no body cavity
