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Mycorrhizae are to the roots of vascular plants as endophytes are to vascular plants'
_____.
A) leaf mesophyll
B) stem apical meristems
C) root apical meristems
D) xylem
Charles Darwin proposed a mechanism for descent with modification that stated that
organisms of a particular species are adapted to their environment when they possess
_____.
A) non-heritable traits that enhance their survival in the local environment
B) non-heritable traits that enhance their survival and reproductive success in the local
environment
C) heritable traits that enhance their survival and reproductive success in the local
environment
D) heritable traits that decrease their survival and reproductive success in the local
environment
Unlike most bony fishes, sharks maintain body fluids that are isoosmotic to seawater, so
they are considered by many to be osmoconformers. Nonetheless, these sharks
osmoregulate at least partially by _____.
A) using their gills and kidneys to rid themselves of sea salts
B) monitoring dehydration at the cellular level with special gated aquaporins
C) tolerating high urea concentrations that are balanced with internal salt concentrations
to seawater osmolarity
D) synthesizing trimethylamine oxide, a chemical that binds and precipitates salts
inside cells
Why do most angiosperms have alternate phyllotaxy, with leaf emergence at an angle of
137.5o compared to leaves above and below?
A) To allow maximum exposure to light
B) To promote a leaf area index above 8
C) To reduce shading of lower leaves
D) To allow maximum exposure to light and to reduce shading of lower leaves
Once a peptide has been formed between the amino acid attached to the tRNA in the P
site and the amino acid associated with the tRNA in the A site, what occurs next?
A) translocation
B) reading of the next codon of mRNA
C) initiation
D) The codon-anticodon hydrogen bonds holding the tRNA in the A site are broken.
A reproductive difference between sea urchins and humans is _____.
A) the sea urchin egg completes meiosis prior to fertilization, but meiosis in humans is
completed after fertilization
B) sea urchin eggs and sperm are of equal size, but human eggs are much bigger than
human sperm
C) sea urchins, but not humans, have a need to block polyspermy, because only in sea
urchins can there be more than one source of sperm to fertilize the eggs
D) sea urchin zygotes get their mitochondria from the sperm, but human zygotes get
their mitochondria from the egg
In an experiment, rats' ovaries were removed immediately after impregnation and then
the rats were divided into two groups. Treatments and results are summarized in the
table above. The results most likely occurred because progesterone exerts an effect on
the _____.
A) general health of the rat
B) metabolism of the uterus
C) gestation period of rats
D) number of eggs fertilized
The first class of drugs developed to treat AIDS, such as AZT, were known as reverse
transcriptase inhibitors. They worked because they _____.
A) targeted and destroyed the viral genome before it could be reverse transcribed into
DNA
B) bonded to the dsDNA genome of the virus in such a way that it could not separate
for replication to occur
C) bonded to the viral reverse transcriptase enzyme, thus preventing the virus from
making a DNA copy of its RNA genome
D) prevented host cells from producing the enzymes used by the virus to replicate its
genome
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
The Brazil nut tree, Bertholletia excels (n = 17), is native to tropical rain forests of
South America. It is a hardwood tree that can grow to over 50 meters tall, is a source of
high-quality lumber, and is a favorite nesting site for harpy eagles. As the rainy season
ends, tough-walled fruits, each containing 8-25 seeds (Brazil nuts), fall to the forest
floor. Brazil nuts are composed primarily of endosperm. About $50 million worth of
nuts are harvested each year. Scientists have discovered that the pale yellow flowers of
Brazil nut trees cannot fertilize themselves and admit only female orchid bees as
pollinators. The agouti (Dasyprocta spp.), a cat-sized rodent, is the only animal with
teeth strong enough to crack the hard wall of Brazil nut fruits. It typically eats some of
the seeds, buries others, and leaves still others inside the fruit, which moisture can now
enter. The uneaten seeds may subsequently germinate.
The harpy eagle, Harpia harpyja, is the largest, most powerful raptor in the Americas. It
nests only in trees taller than 25 meters. It is a 'sloth specialist," but will also take
agouti. Thus, if these eagles capture too many agoutis from a particular locale, they
might contribute to their own demise by _____.
A) having too many offspring
B) decreasing their habitat
C) decreasing atmospheric carbon dioxide
D) increasing the number of sloths
A salamander relies on hydrogen bonding to stick to various surfaces. Therefore, a
salamander would have the greatest difficulty clinging to a _____.
A) slightly damp surface
B) surface of hydrocarbons
C) surface of mostly carbon-oxygen bonds
D) surface of mostly carbon-nitrogen bonds
Refer to the metabolic pathway illustrated above. If A, B, and C are all required for
growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow
on medium supplemented with _____.
A) nutrient A only
B) nutrient B only
C) nutrient C only
D) nutrients A and C
Food moves along the digestive tract as the result of contractions by _____.
A) cardiac muscle
B) smooth muscle
C) striated muscle
D) skeletal muscle
Analysis of a blood sample from a fasting individual who had not eaten for twenty-four
hours would be expected to reveal high levels of _____.
A) insulin
B) glucagon
C) gastrin
D) glucose
At which stage of mitosis are chromosomes usually photographed in the preparation of
a karyotype?
A) prophase
B) metaphase
C) anaphase
D) interphase
Which of the following supports the finding that sugar translocation in phloem is an
active (energy-requiring) process?
A) Sucrose occurs in higher concentrations in companion cells than in the mesophyll
cells where it is produced.
B) Movement of water occurs from xylem to phloem and back again.
C) Strong pH differences exist between the cytoplasm of the companion cell and the
mesophyll cell.
D) ATPases are abundant in the plasma membranes of the mesophyll cells.
Which of the following is an adult organism that has fewer than 1,000 cells?
A) chickens, Gallus domesticus
B) African clawed frogs, Xenopus laevis
C) fruit flies, Drosophila melanogaster
D) nematodes, Caenorhabditis elegans
Normally, only female cats have the tortoiseshell phenotype because _____.
A) a male inherits only one allele of the X-linked gene controlling hair color
B) the Y chromosome has a gene blocking orange coloration
C) only males can have Barr bodies
D) multiple crossovers on the Y chromosome prevent orange pigment production
Suppose researchers marked 800 turtles and later were able to trap a total of 300
individuals in that population, of which 150 were marked. What is the estimate for total
population size?
A) 200
B) 1050
C) 1600
D) 2100
Resource partitioning would be most likely to occur between _____.
A) sympatric populations of species with similar ecological niches
B) sympatric populations of a flowering plant and its specialized insect pollinator
C) allopatric populations of the same animal species
D) allopatric populations of species with similar ecological niches
Which of the following would most likely be an immediate result of a growth factor
binding to its receptor?
A) protein kinase activity
B) adenylyl cyclase activity
C) protein phosphatase activity
D) phosphorylase activity
The following questions are based on the reaction A+ B ↔C+ Dshown in the
accompanying figure.
Which of the following terms best describes the forward reaction in the figure?
A) endergonic, ∆G > 0
B) exergonic, ∆G < 0
C) endergonic, ∆G < 0
D) exergonic, ∆G > 0
The stretch sensors of the sensory neurons in the human knee-jerk reflex are located in
the _____.
A) cartilage of the knee
B) quadriceps muscles on the front side of the thighs
C) hamstring muscles on the back side of the thighs
D) brain, the sensorimotor relay
Plasmids are used as vectors in plant and bacterial genetic engineering. However, there
is a major difference in the fate of genes introduced into bacteria on most bacterial
plasmids and into plants on tumor-inducing (Ti) plasmids. What is this difference?
A) In bacteria, genes are stably expressed; in plants, gene expression is always lost
quickly.
B) Gene expression tends to decrease rapidly and unpredictably in bacteria; gene
expression is much more stable in plants.
C) Bacterial plasmids are circular DNAs; Ti plasmid DNA is linear.
D) Bacterial plasmids and the genes they carry usually are not integrated into the
chromosome; Ti plasmids and the genes they carry are integrated into the chromosome.
Use the figure and the following description to answer the question(s) below.
In a particular plant, leaf color is controlled by gene locus D. Plants with at least one
allele D have dark green leaves, and plants with the homozygous recessive dd genotype
have light green leaves. A true-breeding, dark-leaved plant is crossed with a
light-leaved one, and the F1 offspring is allowed to self-pollinate. The predicted
outcome of the F2 is diagrammed in the Punnett square shown in the figure, where 1, 2,
3, and 4 represent the genotypes corresponding to each box within the square.
Which of the boxes marked 1-4 correspond to plants that will be true-breeding?
A) 1 and 4 only
B) 2 and 3 only
C) 1, 2, 3, and 4
D) 1 only
Coral reefs can be found on the southeast coast of the United States but not at similar
latitudes on the southwest coast. Differences in which of the following most likely
account for this?
A) precipitation
B) day length
C) ocean currents
D) salinity
Certain nutrients are considered "essential" in the diets of some animals because _____.
A) only those animals use those nutrients
B) these animals are not able to synthesize these nutrients
C) the nutrients are necessary coenzymes
D) only certain foods contain them
Which of these provides evidence of the common ancestry of all life?
A) near universality of the genetic code
B) structure of the nucleus
C) structure of cilia
D) structure of chloroplasts
If an African violet has chlorosis, which of the following elements might be a useful
addition to the soil?
A) molybdenum
B) copper
C) iodine
D) magnesium
The oxygen consumed during cellular respiration is involved directly in which process
or event?
A) glycolysis
B) accepting electrons at the end of the electron transport chain
C) the citric acid cycle
D) the oxidation of pyruvate to acetyl CoA
