What is true of the fossil record of mammalian origins?
A) It shows that mammals and birds evolved from the same kind of dinosaur.
B) It includes transitional forms with progressively specialized teeth.
C) It indicates that mammals and dinosaurs did not overlap in geologic time.
D) It includes a series that shows the gradual change of scales into fur.
For the successful development of a vaccine to be used against a pathogen, it is
necessary that _____.
A) the surface antigens of the pathogen stay the same
B) all of the surface antigens on the pathogen be identified
C) the pathogen has only one epitope
D) the major histocompatability (MHC) molecules are heterozygous
Which of the following aspects of eukaryotic reproduction are found only among
invertebrate animals?
A) sexual and asexual reproduction
B) external and internal fertilization
C) hermaphroditism and parthenogenesis
D) fission and budding
Menopause is characterized by _____.
A) the loss of responsiveness by the ovaries to follicle-stimulating hormone (FSH) and
luteinizing hormone (LH)
B) a decline in production of the gonadotropin hormones by the anterior pituitary gland
C) wearing away of the uterine endometrium
D) a halt in the synthesis of gonadotropin-releasing hormone by the brain
A reproductive hormone that is secreted directly from a structure in the brain is _____.
A) estradiol
B) progesterone
C) follicle-stimulating hormone (FSH)
D) gonadotropin-releasing hormone (GnRH)
Prokaryotes are classified as belonging to two different domains. What are the
domains?
A) Bacteria and Eukarya
B) Archaea and Monera
C) Bacteria and Protista
D) Bacteria and Archaea
If isolated plant cells with a water potential averaging -0.5 MPa are placed into a
solution with a water potential of -0.3 MPa, which of the following would be the most
likely outcome?
A) The pressure potential of the cells would increase.
B) Water would move out of the cells.
C) The cell walls would rupture, killing the cells.
D) Solutes would move out of the cells.
Which of the following is a characteristic feature of a carrier protein in a plasma
membrane?
A) It exhibits a specificity for a particular type of molecule.
B) It requires the expenditure of cellular energy to function.
C) It works against diffusion.
D) It has no hydrophobic regions.
To apply parsimony to constructing a phylogenetic tree, _____.
A) choose the tree that assumes all evolutionary changes are equally probable
B) choose the tree in which the branch points are based on as many shared derived
characters as possible
C) choose the tree that represents the fewest evolutionary changes, either in DNA
sequences or morphology
D) choose the tree with the fewest branch points
Over long periods of time, many cave-dwelling organisms have lost their eyes.
Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How
can natural selection account for these losses?
A) Natural selection cannot account for losses, but accounts only for new structures and
functions.
B) Natural selection accounts for these losses by the principle of use and disuse.
C) Under particular circumstances that persisted for long periods, each of these
structures presented greater costs than benefits.
D) The ancestors of these organisms experienced harmful mutations that forced them to
lose these structures.
A zoologist analyzes the jawbones of an extinct mammal and concludes that it was an
herbivore. The zoologist most likely came to this conclusion based upon _____.
A) the position of muscle attachment sites
B) the shape of the teeth
C) the size of the mouth opening
D) the angle of the teeth in the mouth
Behaviors are diverse and important for survival and reproduction. Some behaviors are
learned, such as the species-specific song of a yellow warbler which is different from
the song of a blue-winged warbler. Other behaviors are innate, such as a female cat in
heat urinating more often and in many places to attract a mate or honeybees do a
“dance” that indicates the distance and direction of a food source when they return to
their hive. Which of the following statements supports the idea that behaviors are
important in survival and therefore affect natural selection?
A) Learned behaviors may not necessarily increase fitness. Baby warblers can learn the
song of another species.
B) Innate behaviors are the result of selection for individual survival and reproductive
success.
C) All behaviors are survival mechanisms that increase reproductive fitness by
increasing mutation rates.
D) Both innate and learned behaviors are entirely based on genes inherited from
parents.
Why are there several structurally different pigments in the reaction centers of
photosystems?
A) Excited electrons must pass through several pigments before they can be transferred
to electron acceptors of the electron transport chain.
B) This arrangement enables the plant to absorb light energy of a variety of
wavelengths.
C) They enable the plant to absorb more photons from light energy, all of which are at
the same wavelength.
D) They enable the reaction center to excite electrons to a higher energy level.
Steroid hormones produce their effects in cells by _____.
A) activating key enzymes in metabolic pathways
B) activating translation of certain mRNAs
C) promoting the degradation of specific mRNAs
D) binding to intracellular receptors and promoting transcription of specific genes
Which of the following is the best explanation for the inability of a specific animal cell
to reduce the Ca2+ concentration in its cytosol compared with the extracellular fluid?
A) blockage of the synaptic signal
B) loss of transcription factors
C) insufficient ATP levels in the cytosol
D) low levels of protein kinase in the cell
You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and
exercise. How did the fat leave his body?
A) It was released as CO2 and H2O.
B) It was converted to heat and then released.
C) It was converted to ATP, which weighs much less than fat.
D) It was converted to urine and eliminated from the body.
Several organisms, primarily protists, have what are called intermediate mitotic
organization.
What is the most probable hypothesis about these intermediate forms of cell division?
A) They represent a form of cell reproduction, which must have evolved completely
separately from those of other organisms.
B) They rely on totally different proteins for the processes they undergo.
C) They may be more closely related to plant forms that also have unusual mitosis.
D) They show some but not all of the evolutionary steps toward complete mitosis.
If, someday, an archaean cell is discovered whose rRNA sequence is more similar to
that of humans than the sequence of mouse rRNA is to that of humans, the best
explanation for this apparent discrepancy would be _____.
A) homology
B) homoplasy
C) common ancestry
D) retro-evolution by humans
On the Bahamian island of Andros, mosquitofish populations live in various,
now-isolated, freshwater ponds that were once united. Currently, some predator-rich
ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds
have mosquitofish that can swim continuously for a long time. When placed together in
the same body of water, the two kinds of female mosquitofish exhibit exclusive
breeding preferences.
What is the best way to promote fusion between two related populations of
mosquitofish, one of which lives in a predator-rich pond and the other of which lives in
a predator-poor pond?
A) Build a canal linking the two ponds that permits free movement of mosquitofish, but
not of predators.
B) Transfer only female mosquitofish from a predator-rich pond to a predator-poor
pond.
C) Perform a reciprocal transfer of females between predator-rich and predator-poor
ponds.
D) Remove predators from a predator-rich pond and transfer them to a predator-poor
pond.
Carbohydrates and fats are considered high-energy foods because they _____.
A) have a lot of oxygen atoms.
B) have no nitrogen in their makeup.
C) have a lot of electrons associated with hydrogen.
D) are easily reduced.
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.
When chemical, transport, or mechanical work is done by an organism, what happens to
the heat generated?
A) It is used to power yet more cellular work.
B) It is used to store energy as more ATP.
C) It is used to generate ADP from nucleotide precursors.
D) It is lost to the environment.
Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an
adjacent cell through _____.
A) plasmodesmata
B) tight junctions
C) desmosomes
D) gap junctions
A bone marrow transplant may not be appropriate from a given donor (Jane) to a given
recipient (Jane’s cousin Bob), even though Jane has previously given blood for one of
Bob’s needed transfusions, because _____.
A) even though Jane’s blood type is a match to Bob’s, her major histocompatability
(MHC) proteins may not be a match
B) a blood type match is less stringent than a match required for transplant because
blood is more tolerant of change
C) for each gene, there is only one blood allele but many tissue alleles
D) Jane’s MHC class II genes are not expressed in bone marrow
Which of the following statements regarding extinction is (are) correct?
I) Only a small percentage of species is immune from extinction.
II) Extinction occurs whether humans interfere or not.
III) Extinctions can even be caused indirectly by humans.
A) only I
B) only II
C) only III
D) only II and III
Two primary factors in shaping the polarity of the body axes in chick embryos are
_____.
A) light and temperature
B) salt gradients and membrane potentials
C) gravity and pH
D) moisture and mucus
The reason for differences in the sets of proteins expressed in a nerve and a pancreatic
cell of the same individual is that nerve and pancreatic cells contain different _____.
A) genes
B) regulatory sequences
C) sets of regulatory proteins
D) promoters
Which of the following occurs in meiosis but not in mitosis?
A) chromosome replication
B) synapsis of chromosomes
C) alignment of chromosomes at the equator
D) condensation of chromosomes
Which of these is a karyotype?
A) a display of all of the cell types in an organism
B) organized images of a cell’s chromosomes
C) the appearance of an organism
D) a display of a cell’s mitotic stages
Food web for a particular terrestrial ecosystem
(arrows represent energy flow and letters represent species)
Examine this food web for a particular terrestrial ecosystem. Species C is toxic to
predators. Which species is most likely to benefit from being a mimic of C?
A) A
B) B
C) C
D) E
Which of the following does not occur in prokaryotic gene expression, but does occur
in eukaryotic gene expression?
A) mRNA, tRNA, and rRNA are transcribed.
B) RNA polymerase binds to the promoter.
C) A cap is added to the end of the mRNA.
D) RNA polymerase requires a primer to elongate the molecule.
Among the newly discovered small noncoding RNAs, one type reestablishes
methylation patterns during gamete formation and blocks expression of some
transposons. These are known as _____.
A) miRNA
B) piRNA
C) snRNA
D) siRNA