Post-translational modifications of proteins may include the _____.
A) removal of introns
B) addition of a 5″ cap
C) addition of a poly-A tail
D) addition of carbohydrates to form a glycoprotein
You find a new species of worm and want to classify it. Which of the following lines of
evidence would allow you to classify the worm as a nematode and not an annelid?
A) It is segmented.
B) It is triploblastic.
C) It has a coelom.
D) It sheds its external skeleton to grow.
What is the advantage of having small, needlelike leaves?
A) increased transpiration rate
B) decreased transpiration rate
C) increased efficiency of light capture
D) decreased efficiency of light capture
Which of the following organisms would you expect to have the largest
surface-area-to-volume ratio? Assume that all of the following are the same total length.
A) a mollusk
B) an annelid
C) an arthropod
D) a platyhelminth
Which of the following is a similarity between xylem and phloem transport?
A) Many cells in both tissues have sieve plates.
B) Expenditure of energy from ATP is required.
C) Transpiration is required for both processes.
D) Bulk flow of water is involved.
The eleven pairs of appendages projecting from the rostral area of star-nosed moles are
_____.
A) chemosensory structures
B) tactile structures
C) olfactory structures
D) gustatory structures
Which of the following sex and generation combinations directly produces the pollen
tube of angiosperms?
A) male gametophyte
B) female gametophyte
C) male sporophyte
D) female sporophyte
An animal’s inputs of energy and materials would exceed its outputs if _____.
A) the animal is an endotherm, which must always take in more energy because of its
high metabolic rate
B) it is actively foraging for food
C) it is hibernating
D) it is growing and increasing its mass
In this eight-year experiment, twelve populations of E. coli, each begun from a single
cell, were grown in low-glucose conditions for 20,000 generations. Each culture was
introduced to fresh growth medium every twenty-four hours. Occasionally, samples
were removed from the populations, and their fitness in low-glucose conditions was
tested against that of members sampled from the ancestral (common ancestor) E. coli
population.
Which term best describes what has occurred among the experimental populations of
cells over this eight-year period?
A) microevolution
B) speciation
C) adaptive radiation
D) stabilizing selection
Why does a vegetarian leave a smaller ecological footprint than an omnivore?
A) Fewer animals are slaughtered for human consumption.
B) There is an excess of plant biomass in all terrestrial ecosystems.
C) Vegetarians need to ingest less chemical energy than omnivores.
D) Eating meat is an inefficient way of acquiring photosynthetic productivity.
Which of the following statements correctly describes some aspect of protein secretion
from prokaryotic cells?
A) Prokaryotes cannot secrete proteins because they lack an endomembrane system.
B) The mechanism of protein secretion in prokaryotes is probably the same as that in
eukaryotes.
C) Proteins secreted by prokaryotes are synthesized on ribosomes bound to the
cytoplasmic surface of the plasma membrane.
D) Prokaryotes cannot secrete proteins because they lack ribosomes.
The microsporidian Brachiola gambiae parasitizes the mosquito Anopheles gambiae.
Adult female mosquitoes must take blood meals for their eggs to develop, and it is
while they take blood that they transmit malarial parasites to humans. Male mosquitoes
drink flower nectar. If humans are to safely and effectively use Brachiola gambiae as a
biological control to reduce human deaths from malaria, then how many of the
following statements should be true?
1. Brachiola should kill the mosquitoes before the malarial parasite they carry reaches
maturity.
2. The microsporidian should not be harmful to other insects.
3. Microsporidians should infect mosquito larvae, rather than mosquito adults.
4. The subsequent decline in anopheline mosquitoes should not significantly disrupt
human food resources or other food webs.
5. Brachiola must be harmful to male mosquitoes, but not to female mosquitoes.
A) 2 and 5
B) 1, 2, and 4
C) 2, 3, 5
D) 3 and 4
Which electron carrier(s) function in the citric acid cycle?
A) NAD+ only
B) NADH and FADH2
C) the electron transport chain
D) ADP and ATP
The biological clock controlling circadian rhythms must ultimately_____.
A) depend on environmental cues
B) affect gene transcription
C) stabilize on a 24-hour cycle
D) speed up or slow down with increasing or decreasing temperature
Which one of the following, if missing, would usually prevent translation from starting?
A) exon
B) cap
C) AUG codon
D) poly-A tail
I. II.
III. IV.
Which tree depicts the closest relationship between zygomycetes and chytrids?
A) I
B) II
C) III
D) IV
Identical heat lamps are arranged to shine on two identical containers, one containing
water and one methanol (wood alcohol), so that each liquid absorbs the same amount of
energy minute by minute. The covalent bonds of methanol molecules are nonpolar, so
there are no hydrogen bonds among methanol molecules. Which of the following
graphs correctly describes what will happen to the temperature of the water and the
methanol?
A)
B)
C)
D)
Rhodopsins are light-sensitive molecules composed of a protein (opsin) and retinal
(derivative of vitamin A). Opsin is a membrane protein with several α-helical segments
that loop back and forth through the plasma membrane. There are two classes of
rhodopsins. According to Oded Beje, one class has relatively slow dynamics (a
photocycle of approximately 0.5 second) and is well suited for light detection. The
second class has faster dynamics (a photocycle of approximately 0.02 seconds) and is
well suited for chemiosmosis: pumping of protons or chloride ions across cell
membranes. Oded Beje was the first, in September 2000, to report on a rhodopsin
(proteorhodopsin) found in the domain Bacteria. [SOURCE: O. Beje et al., Science 289
(2000): 1902.]
Which level of protein structure do the α-helix and the β-pleated sheet represent?
A) primary
B) secondary
C) tertiary
D) quaternary
The research team used their experiments to study the incorporation of labeled
nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated
the labeled nucleotide at a significantly higher level after a pathogen was introduced
into the culture. They concluded that _____.
A) the presence of the pathogen made the experiments too contaminated to trust the
results
B) infection causes lymphocytes to divide more rapidly
C) infection causes cell cultures in general to reproduce more rapidly
D) infection causes lymphocyte cultures to skip some parts of the cell cycle
A triploid cell contains sets of three homologous chromosomes. If a cell of a usually
diploid species with 42 chromosomes per cell is triploid, this cell would be expected to
have which of the following?
A) 63 chromosomes in pairs
B) 63 chromosomes in 21 sets of 3
C) 63 chromosomes, each with three chromatids
D) 21 chromosome pairs and 21 unique chromosomes
Which of the following is the correctorder of floral organs from the outside to the inside
of a complete flower?
A) petals → sepals → stamens → carpels
B) sepals → stamens → petals → carpels
C) spores → gametes → zygote → embryo
D) sepals → petals → stamens → carpels
Quaking aspen can send out underground stems for asexual reproduction. Sexual
reproduction is not as common, but when it does happen, the haploid gametes have 19
chromosomes. How many chromosomes are in the cells of the underground stems?
A) 9
B) 10
C) 19
D) 38
The heart rate decreases in response to the arrival of _____.
A) acetylcholine
B) endorphin
C) nitric oxide
D) gamma-aminobutyric acid (GABA)
Currently, two of the living elephant species (X and Y) are placed in the genus
Loxodonta and a third surviving species (Z) is placed in the genus Elephas. Assuming
this classification reflects evolutionary relatedness, which of the following is the most
accurate phylogenetic tree?
A)
B)
C)
D)
What is believed to be the most significant result of the evolution of the amniotic egg?
A) Tetrapods were no longer tied to the water for reproduction.
B) Tetrapods can now function with just lungs.
C) Newborns are much less dependent on their parents.
D) Embryos are protected from predators.
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.
Which of the following is an example of polygenic inheritance?
A) pink flowers in snapdragons
B) the ABO blood group in humans
C) white and purple flower color in peas
D) skin pigmentation in humans
We would expect the greatest difference in plant health between two groups of plants of
the same species, one group with mycorrhizae and one group without mycorrhizae, in
an environment_____.
A) where nitrogen-fixing bacteria are abundant
B) that has soil with poor drainage
C) in which the soil is relatively deficient in mineral nutrients
D) that is near a body of water, such as a pond or river
The genetic code is essentially the same for all organisms. From this, one can logically
assume which of the following?
A) A gene from an organism can theoretically be expressed by any other organism.
B) DNA was the first genetic material.
C) The same codons in different organisms translate into different amino acids.
D) Different organisms have different types of amino acids.
Which of the following is the best definition of autoimmune disease?
A) a condition in which B cells and T cells respond independently to antigens and do
not interact correctly
B) a condition in which the adaptive immune system fails to recognize the second
infection by the same antigen
C) a condition in which self molecules are treated as non-self
D) a condition in which the immune system creates random antibodies without being
triggered by an antigen
In examining an unknown animal species during its embryonic development, how can
you be sure what you are looking at is a protostome and not a deuterostome?
A) There is evidence of cephalization.
B) The animal is triploblastic.
C) The animal is clearly bilaterally symmetrical.
D) You see a mouth, but not an anus.
An oil-water mixture works as an insecticidal spray against mosquitoes and other
insects because it _____.
A) blocks the openings into the tracheal system
B) interferes with gas exchange across the capillaries
C) clogs their bronchi
D) prevents gases from leaving the atmosphere
Hershey and Chase used a DNA-based virus for their work. What would the results
have been if they had used an RNA virus?
A) With an RNA virus radioactive protein would have been in the final pellet.
B) With an RNA virus radioactive RNA would have been in the final pellet.
C) With an RNA virus neither sample would have had a radioactive pellet.
D) With an RNA virus the protein shell would have been radioactive in both samples.
In which of the following pairs are the two terms equivalent?
A) ovule egg
B) embryo sac female gametophyte
C) seed zygote
D) microspore pollen grain