Natural selection involves energetic trade-offs between _____.
A) choosing how many offspring to produce over the course of a lifetime and how long
to live
B) producing large numbers of gametes when employing internal fertilization versus
fewer numbers of gametes when employing external fertilization
C) increasing the number of individuals produced during each reproductive episode and
a corresponding decrease in parental care
D) high survival rates of offspring and the cost of parental care
Urea is _____.
A) insoluble in water
B) the primary nitrogenous waste product of humans
C) the primary nitrogenous waste product of most birds
D) the primary nitrogenous waste product of most aquatic invertebrates
Many terrestrial arthropods exchange gases with their environments by using tracheae,
tubes that lead from openings (called spiracles) in the animal’s exoskeleton or cuticle
directly to the animal’s tissues. Some arthropods can control whether their spiracles are
opened or closed; opening the spiracles allows the carbon dioxide produced in the
tissues to travel down the tracheae and be released outside the animal. Klok et al.
measured the carbon dioxide emitted over time (represented by ) by several
species of centipedes. The figure below presents graphs of their results for two species,
Cormocephalus morsitans and Scutigerina weberi. (C. J. Klok, R. D. Mercer, and S. L.
Chown. 2002. Discontinuous gas-exchange in centipedes and its convergent evolution
in tracheated arthropods. Journal of Experimental Biology 205:1019-29.) Copyright
2002 The Company of Biologists and the Journal of Experimental Biology.
Compare the graphs in the figure above of carbon dioxide (CO2) emission for
Cormocephalus morsitans and Scutigerina weberi. What hypothesis can you make
about each centipede’s habitat?
A) C. morsitans lives in a habitat that provides more carbon dioxide than does S.
weberi.
B) C. morsitans lives in a habitat with more predators than does S. weberi.
C) C. morsitans lives in a colder habitat than does S. weberi.
D) C. morsitans lives in a drier habitat than does S. weberi.
Fishes that have swim bladders can regulate their density and, thus, their buoyancy.
There are two types of swim bladder: physostomous and physoclistous. The ancestral
version is the physostomous version, in which the swim bladder is connected to the
esophagus via a short tube (see the figure above). The fish fills this version by
swimming to the surface, taking gulps of air, and directing them into the swim bladder.
Air is removed from this version by “belching.” The physoclistous version is more
derived, and has lost its connection to the esophagus. Instead, gas enters and leaves the
swim bladder via special circulatory mechanisms within the wall of the swim bladder.
We should expect the inner wall of the swim bladder to be lined with tissue that is
derived from _____.
A) ectoderm
B) endoderm
C) mesoderm
D) mesoglea
Among these choices, the largest cell involved in frog reproduction is _____.
A) an egg
B) a blastomere in the vegetal pole
C) a blastomere in the animal pole
D) one of the products of the first cleavage
The archenteron of a frog develops into the _____.
A) blastocoel
B) endoderm
C) placenta
D) lumen of the digestive tract
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.
If the vertical axis of the figure above refers to relative fitness, then which of the
following is the most valid and accurate measure of fitness?
A) number of daughter cells produced per mother cell per generation
B) average swimming speed of cells through the growth medium
C) amount of glucose synthesized per unit time
D) number of generations per unit time
At the time of implantation, the human embryo is called a _____.
A) blastocyst
B) gastrula
C) fetus
D) zygote
Upon activation by stomach acidity, the secretions of the parietal cells _____.
A) initiate the chemical digestion of protein in the stomach
B) initiate the mechanical digestion of lipids in the stomach
C) initiate the chemical digestion of lipids in the stomach
D) delay digestion until the food arrives in the small intestine
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
Giardia intestinalis is an intestinal parasite of humans and other mammals that causes
intestinal ailments in most people who ingest the cysts. Upon ingestion, each cyst
releases two motile cells, called trophozoites. These attach to the small intestine’s lining
via a ventral adhesive disk. The trophozoites anaerobically metabolize glucose from the
host’s intestinal contents to produce ATP. Reproduction is completely asexual, occurring
by longitudinal binary fission of trophozoites, with each daughter cell receiving two
haploid nuclei (n = 5). A trophozoite will often encyst as it passes into the large
intestine by secreting around itself a case that is resistant to cold, heat, and dehydration.
Infection usually occurs by drinking untreated water that contains cysts.
Giardia’s mitosome can be said to be “doubly degenerate,” because it is a degenerate
type of ________, an organelle that is itself a degenerate form of ________.
A) nucleus; archaean
B) nucleus; bacterium
C) mitochondria; proteobacterium
D) mitochondria; spirochete
What happens if MPF (mitosis-promoting factor) is introduced into immature frog
oocytes that are arrested in G2?
A) Nothing happens.
B) The cells undergo meiosis.
C) The cells enter mitosis.
D) Cell differentiation is triggered.
Which of the life cycles is typical for animals?
A) I only
B) II only
C) III only
D) I and III
Because they both produce a reverse transcriptase, long interspersed nuclear elements
(LINEs) as transposable elements may be related to _____.
A) plasmids
B) retroviruses
C) poliovirus
D) parasitic bacteria
A gardener in Canada wants to surprise his mother on her birthday and make her
favorite hibiscus bush flower in May instead of at the end of June. The bush is growing
in the greenhouse. Which of the following might make the hibiscus bush flower early?
A) grafting leaves of a hibiscus that was exposed to long night
B) grafting leaves of a hibiscus that was exposed to short night
C) exposing flower buds of the hibiscus bush to long nights
D) exposing flower buds of the hibiscus bush to short nights
Osmoregulatory adjustment via the renin-angiotensin-aldosterone system can be
triggered by _____.
A) sleeping for one hour
B) severe sweating on a hot day
C) eating a pizza with olives and pepperoni
D) drinking several glasses of water
Trace elements are those required by an organism in only minute quantities. Which of
the following is a trace element that is required by humans and other vertebrates, but
not by other organisms such as bacteria or plants?
A) calcium
B) iodine
C) sodium
D) phosphorus
Which of the following were probably factors that permitted early plants to successfully
colonize land?
1. the relative number of potential predators (herbivores)
2. the relative number of competitors
3. the relative availability of symbiotic partners
4. air’s relative lack of support, compared to water’s support
A) 1 and 2
B) 2 and 3
C) 3 and 4
D) 1, 2, and 3
Who might be interested in using cytokinins?
A) grocers, to spray on fruit to enhance ripening in the store
B) consumers, to spray on fruit before eating to enhance taste
C) florists, to dip stems in to keep leaves green longer
D) farmers, to spray on fruit after picking to stall ripening
Eukaryotes that are not closely related and that do not share many anatomical
similarities can still be placed together on the same phylogenetic tree by comparing
their _____.
A) plasmids
B) mitochondrial genomes
C) homologous genes that are poorly conserved
D) homologous genes that are highly conserved
Three lab groups carried out an experiment to identify the correct molarities for five
solutions. Each unknown contained one of the following sucrose concentrations: 0.0 M,
0.2 M, 0.4 M, 0.6 M, 0.8 M, and 1.0 M. Each data entry represents the average of 3
sample replications of 1 cm3 sweet potato cubes expressed as percent change in mass
after an overnight (24 hr) soak in the unknown solutions. From the data given, which
statement most accurately describes what is occurring in response to a particular
unknown solution.
A) Unknown solution E contains the highest concentration of sucrose and the change in
mass is due to the active transport of sucrose into the cell in exchange for water
molecules.
B) Osmosis of water molecules from unknown solution A likely caused the increase in
mass observed.
C) Passive transport of sucrose out of the potato cells explains the change in mass
observed for unknown solution F.
D) Unknown solution C represents a sucrose molarity slightly lower than the molarity
of sweet potato cells, thus water is transported out of the cells.
Arrange the following taxonomic terms in order from most inclusive (most general) to
least inclusive (most specific).
1. apes
2. hominins
3. Homo
4 anthropoids
5. primates
A) 5, 1, 4, 2, 3
B) 5, 4, 1, 2, 3
C) 5, 4, 2, 1, 3
D) 5, 2, 1, 4, 3
Which of the following describes the events of apoptosis?
A) The cell dies, it is lysed, its organelles are phagocytized, and its contents are
recycled.
B) The cell’s DNA and organelles become fragmented, the cell dies, and it is
phagocytized.
C) The cell’s DNA and organelles become fragmented, the cell shrinks and forms blebs,
and the cell’s parts are packaged in vesicles that are digested by specialized cells.
D) The cell’s nucleus and organelles are lysed, then the cell enlarges and bursts.
In what respect do hominins differ from all other anthropoids?
A) lack of a tail
B) eyes on the front of the face
C) bipedal posture
D) opposable thumbs
In some parts of Africa, the frequency of heterozygosity for the sickle-cell anemia allele
is unusually high, presumably because this reduces the frequency of malaria. Such a
relationship is related to which of the following?
A) Mendel’s law of independent assortment
B) Mendel’s law of segregation
C) Darwin’s explanation of natural selection
D) the malarial parasite changing the allele
If organisms A, B, and C belong to the same class but to different orders and if
organisms C, D, and E belong to the same order but to different families, which of the
following pairs of organisms would be expected to show the greatest degree of
structural homology?
A) A and D
B) B and D
C) B and C
D) D and E
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
If in the future the current molecular evidence regarding animal origins is further
substantiated, what will be true of any contrary evidence regarding the origin of animals
derived from the fossil record?
A) The contrary fossil evidence will be seen as a hoax.
B) The fossil evidence will be understood to have been interpreted incorrectly because
it is incomplete.
C) The fossil record will henceforth be ignored.
D) Phylogenies involving even the smallest bit of fossil evidence will need to be
discarded.
Examine the figure above and consider this hypothesis: Plant biomass increases with
species richness. In looking at the data in the figure above, how would you relate it to
this hypothesis? The hypothesis is _____.
A) partially supported
B) supported
C) rejected
Animals that help other animals of the same species _____.
A) have excess energy reserves
B) are bigger and stronger than the other animals
C) are usually related to the other animals helped
D) are always male
If you place a small piece of a cracker on your tongue, what would you expect to
happen?
A) The vitamins in the cracker are immediately absorbed.
B) Salivary amylase degrades the starch from the cracker into glucose.
C) The proteins in the cracker begin to be digested.
D) The flavor becomes less noticeable because the sugars are digested.
Proton pumps are used in various ways by members of every domain of organisms:
Bacteria, Archaea, and Eukarya. What does this most probably mean?
A) Proton gradients across a membrane were used by cells that were the common
ancestor of all three domains of life.
B) The high concentration of protons in the ancient atmosphere must have necessitated
a pump mechanism.
C) Cells of each domain evolved proton pumps independently when oceans became
more acidic.
D) Proton pumps are necessary to all cell membranes.
At some time during their life cycles, bryophytes make _____.
A) microphylls
B) true roots
C) true leaves
D) sporangia
In the figure, when new viruses are being assembled at the point marked IV, what
mediates the assembly?
A) host cell chaperones
B) assembly proteins coded for by the host nucleus
C) assembly proteins coded for by the viral genes
D) nothing; they self-assemble
The main cause of the increase in the amount of carbon dioxide in Earth’s atmosphere
over the past 150 years is _____.
A) increased worldwide primary production
B) an increase in the amount of infrared radiation absorbed by the atmosphere
C) the burning of larger amounts of wood and fossil fuels
D) additional respiration by the rapidly growing human population