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The active ingredient orlistat acts to decrease the amount of fat that is absorbed by
attaching to enzymes that digest fat. Which of the following are potential targets of
orlistat?
A) salivary amylase
B) pepsidase
C) pancreatic lipase
D) secretin
The membranes of winter wheat are able to remain fluid when it is extremely cold by
_____.
A) increasing the percentage of unsaturated phospholipids in the membrane
B) increasing the percentage of cholesterol molecules in the membrane
C) decreasing the number of hydrophobic proteins in the membrane
D) cotransport of glucose and hydrogen
Infant mortality and life expectancy at birth in developed and developing countries
(data as of 2005).
What is a logical conclusion that can be drawn from the graphs above? Developed
countries have _____.
A) lower infant mortality rates and lower life expectancy than developing countries
B) higher infant mortality rates and lower life expectancy than developing countries
C) lower infant mortality rates and higher life expectancy than developing countries
D) higher infant mortality rates and higher life expectancy than developing countries
Sequencing an entire genome, such as that of C. elegans, a nematode, is most important
because _____.
A) it allows researchers to use the sequence to build a "better" nematode, which is
resistant to disease
B) it allows research on a group of organisms we do not usually care much about
C) a sequence that is found to have a particular function in the nematode is likely to
have a closely related function in vertebrates
D) a sequence that is found to have no introns in the nematode genome is likely to have
acquired the introns from higher organisms
In which of the following situations would you expect to find the largest number of
K-selected individuals?
A) a recently abandoned agricultural field in Ohio
B) a shifting sand dune community of south Lake Michigan
C) an old-growth forest
D) South Florida after a hurricane
Where are the youngest wood and the youngest bark in a tree trunk?
A) Youngest wood is in the center of a tree; youngest bark is the outside of the bark.
B) Youngest wood is in the center of a tree; youngest bark is the inner part, next to the
vascular cambium.
C) Youngest wood is toward the outside, near the vascular cambium; youngest bark is
the outside of the bark.
D) Youngest wood is toward the outside, near the vascular cambium; youngest bark is
the inner part, next to the vascular cambium.
Large numbers of ribosomes are present in cells that specialize in producing which of
the following molecules?
A) lipids
B) glycogen
C) proteins
D) nucleic acids
Which of the following dissociates completely in solution and is considered to be a
strong base (alkali)?
A) HCl
B) NH3
C) H2CO3
D) NaOH
What results from an unequal sharing of electrons between atoms?
A) a nonpolar covalent bond
B) a polar covalent bond
C) an ionic bond
D) a hydrophobic interaction
Use the following information to answer the question(s) below.
Healthy individuals of Paramecium bursaria contain photosynthetic algal
endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to
as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gather at
the well-lit side, whereas other species of Paramecium gather at the opposite side. The
zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its
zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two
ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria)
are absent from its habitat, P. bursaria will digest its zoochlorellae.
Which term best describes the symbiotic relationship of well-fed P. bursaria to their
zoochlorellae?
A) mutualistic
B) parasitic
C) predatory
D) pathogenic
Consider the global nitrogen cycle depicted in the figure above. How are humans
altering this cycle?
A) industrial nitrogen fixation
B) nitrogen lost to the atmosphere
C) reduction of nitrogen available to terrestrial ecosystems
D) reduction of nitrogen fixation by bacteria
Use the following information to answer the questions below.
In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in
the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off
as a molecule of CO2, (2) is oxidized to form a two-carbon compound called acetate,
and (3) is bonded to coenzyme A.
Which of the following events takes place in the electron transport chain?
A) the breakdown of glucose into two pyruvate molecules
B) the breakdown of an acetyl group to carbon dioxide
C) the extraction of energy from high-energy electrons remaining from glycolysis and
the citric acid cycle
D) substrate-level phosphorylation
Cytochalasin D is a drug that prevents actin polymerization. A cell treated with
cytochalasin D will still be able to _____.
A) divide in two
B) contract muscle fibers
C) extend pseudopodia
D) move vesicles within a cell
It has been observed that organisms on islands are different from, but closely related to,
similar forms found on the nearest continent. This is taken as evidence that ____.
A) island forms are descended from mainland forms
B) common environments are inhabited by the same organisms
C) island forms and mainland forms have identical gene pools
D) the island forms and mainland forms are converging
Your professor wants you to construct a phylogenetic tree of orchids. She gives you
tissue from seven orchid species and one lily. What is the most likely reason she gave
you the lily?
A) to serve as an outgroup
B) to see if the lily is a cryptic orchid species
C) to see if the lily and the orchids show all the same shared derived characters
(synapomorphies)
D) to demonstrate likely homoplasies
Female spotted sandpipers aggressively court males and, after mating and egg laying,
leave the clutch of young for the male to incubate. This sequence may be repeated
several times with different males until no available males remain, forcing the female to
incubate her last clutch. Which of the following terms best describes this behavior?
A) monogamy
B) polygyny
C) polyandry
D) promiscuity
Use the following information to answer the question(s) below.
In 1983 a population of dark-eyed junco birds became established on the campus of the
University of California, San Diego (UCSD), which is located many miles from the
junco's normal habitat in the mixed-coniferous temperate forests in the mountains.
Juncos have white outer tail feathers that the males display during aggressive
interactions and during courtship displays. Males with more white in their tail are more
likely to win aggressive interactions, and females prefer to mate with males with more
white in their tails. Females have less white in their tails than do males, and display it
less often. (Pamela J. Yeh. 2004. Rapid evolution of a sexually selected trait following
population establishment in a novel habitat. Evolution 58[1]:166-74.)
Refer to the paragraph on dark-eyed junco birds. The UCSD campus male junco
population tails are about 36% white, whereas the tails of males from nearby mountain
populations are about 40-45% white. The founding stock of UCSD birds was likely
from the nearby mountain populations because some of those birds overwinter on the
UCSD campus each year. Population sizes on the UCSD campus have been reasonably
large, and there are significant habitat differences between the UCSD campus and the
mountain coniferous forests; UCSD campus has a more open environment (making
birds more visible) and a lower junco density (decreasing intraspecific competition)
than that in the mountain forests. Given this information, which of the following
evolutionary mechanisms do you think is most likely responsible for the difference
between the UCSD and mountain populations?
A) natural selection
B) genetic drift
C) gene flow
D) mutation
Orchid seeds are tiny, with virtually no endosperm and with miniscule cotyledons. If
such seeds are deposited in a dark, moist environment, then which of the following
represents the most likely means by which fungi might assist in seed germination, given
what the seeds lack?
A) by transferring some chloroplasts to the embryo in each seed
B) by providing the seeds with water and minerals
C) by providing the embryos with some of the organic nutrients they have absorbed
D) by strengthening the seed coat that surrounds each seed
Mammalian eyes sense light because the photoreceptor cells have molecules called
opsins, which change structure when exposed to light. Which of the following plant
molecules would be analogous to mammalian opsins in their light-sensing ability?
A) auxin and phytochrome
B) auxin and Pfr
C) Pfr and phytochrome
D) cytokinins and phototropins
The earliest known mineralized structures in vertebrates are associated with _____.
A) feeding
B) locomotion
C) defense
D) respiration
DNA sequencing has transformed our understanding of genes, genomes and evolution.
Which of the following statements comparing two common sequencing techniques, the
chain termination method and next generation sequencing is TRUE?
A) The chain termination method is faster and more efficient, so it is used to generate
large-scale sequences, while next generation synthesis is used for routine, small-scale
jobs.
B) The chain termination method employs the polymerase chain reaction, but next
generation sequencing does not.
C) In the chain termination method, the order of bases is detected by fluorescently
labeling each dideoxy-nucleotide in a different color, while next generation sequencing
determines the order of bases by detecting the release of PPi during the formation of the
phosphodiester bond.
D) Next generation sequencing employs electrophoresis, but the chain termination
method does not.
Use the following information to answer the question(s) below.
About 3 million years ago, the Isthmus of Panama (a narrow strip of land connecting
North and South America) formed, dividing marine organisms into Pacific and
Caribbean populations. Researchers have examined species of snapping shrimp on both
sides of the isthmus. Based on the morphological species concept, there appeared to be
seven pairs of species, with one species of each pair in the Pacific and the other in the
Caribbean. The different species pairs live at somewhat different depths in the ocean.
Using mitochondrial DNA sequences, the researchers estimated phylogenies and found
that each of these species pairs, separated by the isthmus, were indeed each other's
closest relatives. The researchers investigated mating in the lab and found that many
species pairs were not very interested in courting with each other, and any that did mate
almost never produced fertile offspring. (N. Knowlton, L. A. Weigt, L. A. Solorzano, D.
K. Mills, and E. Bermingham. 1993. Divergence in proteins, mitochondrial DNA, and
reproductive incompatibility across the Isthmus of Panama. Science 260:1629-32.)
Which of the following describes the most likely order of events in allopatric
speciation?
A) genetic drift, genetic isolation, divergence
B) genetic isolation, divergence, genetic drift
C) divergence, genetic drift, genetic isolation
D) genetic isolation, genetic drift, divergence
The following questions are based on the 15 molecules illustrated in the accompanying
figure. Each molecule may be used once, more than once, or not at all.
Which of the following molecules is a purine nitrogenous base?
A) 2
B) 5
C) 12
D) 13
Which of these events occurs first in seed germination?
A) Cell division occurs in the embryo and growth starts.
B) Mitochondria multiply and provide energy for growth processes.
C) Water is taken up.
D) Oxygen is produced and proteins are synthesized.
Motor proteins provide for molecular motion in cells by interacting with what types of
cellular structures?
A) membrane proteins of the inner nuclear envelope
B) free ribosomes and ribosomes attached to the ER
C) components of the cytoskeleton
D) cellulose fibers in the cell wall
Why is carbon so important in biology?
A) It is a common element on Earth.
B) It has very little electronegativity, making it a good electron donor.
C) It bonds to only a few other elements.
D) It can form a variety of carbon skeletons and host functional groups.
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.
Which of the following components of the immune system destroys bacteria in a way
similar to an antitank weapon destroying armored military tanks by punching holes in
the wall of the bacteria?
A) complement protein
B) macrophages
C) plasma cells
D) major histocompatibility complex proteins
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.
In the figure above, meiosis is most likely to be represented by which number(s)?
A) 2
B) 4
C) 2 and 8
D) 10 and 12
The "motor unit" in vertebrate skeletal muscle refers to _____.
A) one actin binding site and its myosin partner
B) one sarcomere and all of its actin and myosin filaments
C) one myofibril and all of its sarcomeres
D) one motor neuron and all of the muscle fibers on which it has synapses
When comparing root systems of corn plants growing on a square foot in a cornfield
with the root systems of natural prairie plants growing in a meadow, what result do you
expect to see?
A) The overall mass of roots will be identical in a cornfield and on a meadow.
B) The mass and length of roots in a cornfield will be higher because soil is fertilized.
C) The mass and length of roots on a meadow will be higher because soil is poorer and
there is higher diversity of plants.
D) The overall mass of roots on a meadow will be lower, but the length will be higher
since roots need to grow deeper to reach nutrients.
What is meant by the description "antiparallel" regarding the strands that make up
DNA?
A) The twisting nature of DNA creates nonparallel strands.
B) The 5' to 3' direction of one strand runs counter to the to direction of the other
strand.
C) Base pairings create unequal spacing between the two DNA strands.
D) One strand contains only purines and the other contains only pyrimidines.
Which of the following will increase the speed of an action potential moving down an
axon?
I) Action potentials move faster in larger diameter axons.
II) Action potentials move faster in axons lacking potassium ion channels.
III) Action potentials move faster in myelinated axons.
A) only I and II
B) only II and III
C) only I and III
D) I, II, and III
