Which of the following is a consequence of biological magnification
(biomagnification)?
A) Toxic chemicals in the environment pose greater risk to top-level predators than to
primary consumers.
B) Populations of top-level predators are generally smaller than populations of primary
consumers.
C) Only a small portion of the energy captured by producers is transferred to
consumers.
D) The amount of biomass in the producer level of an ecosystem decreases if the
producer turnover time increases.
In a newly fertilized egg, the vitelline layer _____.
A) lifts away from the egg and hardens to form a fertilization envelope
B) secretes hormones that enhance steroidogenesis by the ovary
C) reduces the loss of water from the egg and prevents desiccation
D) provides most of the nutrients used by the zygote
Use this information to answer the question(s) below.
A researcher introduces double-stranded RNA into a culture of mammalian cells and
can identify its location or that of its smaller subsections experimentally, using a
fluorescent probe.
When she finds that the introduced strand separates into single-stranded RNAs, what
other evidence of this single-stranded RNA piece’s activity can she find?
A) She can measure the degradation rate of the remaining single strand.
B) The rate of accumulation of the polypeptide encoded by the target mRNA is reduced.
C) The amount of miRNA is multiplied by its replication.
D) The cell’s translation ability is entirely shut down.
Proteomics is defined as the _____.
A) linkage of each gene to a particular protein
B) study of the full protein set encoded by a genome
C) totality of the functional possibilities of a single protein
D) study of how amino acids are ordered in a protein
An example of antagonistic hormones controlling homeostasis is _____.
A) thyroxine and parathyroid hormone in calcium balance
B) insulin and glucagon in glucose metabolism
C) progestins and estrogens in sexual differentiation
D) epinephrine and norepinephrine in fight-or-flight responses
Use the following information to answer the question(s) below.
An otherwise healthy student in your class is infected with EBV, the virus that causes
infectious mononucleosis. The same student had already been infected when she was a
child, at which time she had merely experienced a mild sore throat and swollen lymph
nodes in her neck. This time, though infected, she does not get sick.
The EBV antigen fragments will be presented by the virus-infected cells along with
_____.
A) a complement
B) antibodies
C) class I MHC molecules
D) class II MHC molecules
Which of the following organs is correctly paired with its function?
A) stomach protein digestion
B) large intestine bile production
C) small intestine starch digestion
D) pancreas starch digestion
If a tunicate’s pharyngeal gill slits were suddenly blocked, the animal would have
trouble _____.
A) respiring
B) feeding
C) moving
D) respiring and feeding
In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling
serves which function?
A) formation of mating complexes
B) aggregation of bacteria that can cause cavities
C) secretion of substances that inhibit foreign bacteria
D) digestion of unwanted parasite populations
Use the following information to answer the question(s) below.
Diploid nuclei of the ascomycete, Neurospora crassa, contain 14 chromosomes. A
single diploid cell in an ascus will undergo one round of meiosis, followed in each of
the daughter cells by one round of mitosis, producing a total of eight ascospores.
If a single, diploid G2 nucleus in an ascus contains 400 nanograms (ng) of DNA, then a
single ascospore nucleus of this species should contain how much DNA (ng), carried on
how many chromosomes?
A) 100, carried on 7 chromosomes
B) 100, carried on 14 chromosomes
C) 200, carried on 7 chromosomes
D) 200, carried on 14 chromosomes
Clay in soils represents a trade-off in nutrient availability, such that _____.
A) anions are less likely to leach out of soil and are difficult for plants to extract
B) cations are less likely to leach out of soil and are difficult for plants to extract
C) nitrogen levels are exceptionally high, but much of the nitrogen leaches away
D) oxygen levels are exceptionally high, but much of the nitrogen leaches away
Sutherland discovered that the signaling molecule epinephrine _____.
A) brings about a decrease in levels of cAMP as a result of bypassing the plasma
membrane
B) causes lower blood glucose by binding to liver cells
C) interacts directly with glycogen phosphorylase
D) elevates cytosolic concentrations of cyclic AMP
Using modern techniques of sequencing by synthesis and the shotgun approach,
sequences are assembled into chromosomes by ______.
A) placing them on previously generated genetic maps.
B) cloning them into plasmid vectors.
C) computer analysis looking for sequence overlaps.
D) cloning them into plasmid vectors, placing them on previously generated genetic
maps, followed by computer analysis looking for sequence overlaps.
Which organelle often takes up much of the volume of a plant cell?
A) lysosome
B) vacuole
C) Golgi apparatus
D) peroxisome
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
Based on the intermediate disturbance hypothesis, a community’s species diversity is
increased by _____.
A) frequent massive disturbance
B) stable conditions with no disturbance
C) moderate levels of disturbance
D) intensive disturbance by humans
Which of the following would be inhibited by a drug that specifically blocks the
addition of phosphate groups to proteins?
A) G protein-coupled receptor binding
B) ligand-gated ion channel signaling
C) adenylyl cyclase activity
D) receptor tyrosine kinase activity
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.
The major function of the medicinal compounds in plants is to _____.
A) attract pollinators for seed dispersal
B) attract insects and birds to spread seeds and fruits
C) defend the plant against herbivores
D) defend the plant against microbes
A plant developed a mineral deficiency after being treated with a fungicide. What is the
most probable cause of the deficiency?
A) Mineral receptor proteins in the plant membrane were not functioning.
B) Mycorrhizal fungi were killed.
C) Active transport of minerals was inhibited.
D) Proton pumps reversed the membrane potential.
Which of the following statements about human evolution is correct?
A) Modern humans are the only human species to have evolved on Earth.
B) Human ancestors were virtually identical to extant chimpanzees.
C) Human evolution has occurred within an unbranched lineage.
D) The upright posture and enlarged brain of humans evolved separately.
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
As big as it is, the ocean is nutrient-limited. If you wanted to investigate this
phenomenon, one reasonable approach would be to _____.
A) observe Antarctic Ocean productivity from year to year to see if it changes
B) experimentally enrich some areas of the ocean and compare their productivity to that
of untreated areas
C) compare nutrient concentrations between the photic zone and the benthic zone in
various marine locations
D) contrast nutrient uptake by autotrophs in marine locations that are different
temperatures
Which of the following types of mutation would convert a proto-oncogene into an
oncogene?
A) a mutation that blocks transcription of the proto-oncogene
B) a mutation that creates an unstable proto-oncogene mRNA
C) a mutation that greatly increases the amount of the proto-oncogene protein
D) a deletion of most of the proto-oncogene coding sequence
Based on this tree, which statement is NOT correct?
A) The salamander lineage is a basal taxon.
B) Salamanders are a sister group to the group containing lizards, goats, and humans.
C) Salamanders are as closely related to goats as to humans.
D) Lizards are more closely related to salamanders than to humans.
The following questions refer to the generalized life cycle for land plants shown in the
figure below. Each number within a circle or square represents a specific plant or plant
part, and each number over an arrow represents either meiosis, mitosis, or fertilization.
The embryo sac of an angiosperm flower is best represented by which number in the
figure above?
A) 1
B) 3
C) 7
D) 11
Use the following information to answer the question(s) below.
Due to its system of air sacs connected to the lungs, the respiratory system of birds is
arguably the most effective respiratory system of all air-breathers. Upon inhalation, air
first flows into posterior air sacs, then into the lungs, and then into anterior air sacs on
the way to being exhaled. Thus, there is one-way flow of air through the lungs, along
thousands of tubules called parabronchi.
If the inner lining of the air sacs is neither thin nor highly vascularized, then what can
be inferred about the air sacs?
A) They must not belong to the respiratory system.
B) They cannot be derived from endoderm.
C) They are not efficient sites of gas exchange between air and blood.
D) They cannot effectively moisturize the air before it reaches the lungs.
Which of the following statements are fundamental to the clonal-selection theory of
how the adaptive immune system functions?
I) Each lymphocyte has a unique membrane receptor that recognizes one antigen.
II) When the lymphocyte binds an antigen, it is activated and begins dividing to form
many identical copies of itself.
III) Cloned lymphocytes have slight differences and are selected by the spleen for
removal if they do not bind an antigen.
IV) Cloned cells descend from an activated lymphocyte and persist even after the
pathogen is eliminated.
A) only I and III
B) only II and IV
C) only I, II, and IV
D) only II, III, and IV
Diffusion _____.
A) is very rapid over long distances
B) requires an expenditure of energy by the cell
C) is a passive process in which molecules move from a region of higher concentration
to a region of lower concentration
D) requires integral proteins in the cell membrane
Examine the digestive system structures in the figure above. The agents that help
emulsify fats are produced in location _____.
A) 1
B) 3
C) 8
D) 9