What is a telomere?
A) the mechanism that holds two sister chromatids together
B) DNA replication during telophase
C) the site of origin of DNA replication
D) the ends of linear chromosomes
What do all deuterostomes have in common?
A) Adults are bilaterally symmetrical.
B) Embryos have pharyngeal pouches that may or may not form gill slits.
C) All have a spinal column.
D) The pore (blastopore) formed during gastrulation becomes the anus.
Which of the following are characteristic of both rhizobia and mycorrhizae?
I) They both benefit by receiving sugars from the plant.
II) They both become parasitic in nutrient-rich environments.
III) They both enhance the growth of most plants.
IV) They both are found in most ecosystems of the world.
A) only I and II
B) only I, III, and IV
C) only III and IV
D) I, II, III, and IV
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
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
What does the biological species concept use as the primary criterion for determining
species boundaries?
A) geographic isolation
B) niche differences
C) gene flow
D) morphological similarity
Two groups of tomatoes were grown under laboratory conditions, one with humus
added to the soil and one a control without humus. The leaves of the plants grown
without humus were yellowish (less green) compared with those of the plants grown in
the humus-enriched soil. The best explanation for this difference is that_____.
A) the healthy plants used the food in the decomposing leaves of the humus for energy
to make chlorophyll
B) the humus made the soil more loosely packed, so water penetrated more easily to the
roots
C) the humus contained minerals such as magnesium and iron, needed for the synthesis
of chlorophyll
D) the heat released by the decomposing leaves of the humus caused more rapid growth
and chlorophyll synthesis
There are several properties that are characteristic of a soil in which typical plants
would grow well. Of the following, which would be the least conducive to plant
growth?
A) abundant humus
B) numerous soil organisms
C) compacted soil
D) high cation exchange capacity
Which of the following can function in signal transduction in plants ?
I) calcium ions
II) nonrandom mutations
III) receptor proteins
IV) autochrome
V) secondary messengers
A) only I, III, and IV
B) only I, II, and V
C) only I, III, and V
D) only II, III, and V
Immunological memory accounts for _____.
A) the human body’s ability to distinguish self from non-self
B) the observation that some strains of the pathogen that causes dengue fever cause
more severe disease than others
C) the ability of a helper T cell to signal B cells via cytokines
D) the ancient observation that someone who had recovered from the plague could
safely care for those newly diseased
Which of the following studies would a community ecologist undertake to learn about
competitive interactions?
I) selectivity of nest sites among cavity-nesting songbirds
II) the grass species preferred by grazing pronghorn antelope and bison
III) stomach analysis of brown trout and brook trout in streams where they coexist
A) only I and II
B) only I and III
C) only II and III
D) I, II, and III
The eight climographs below show yearly temperature (line graph and left vertical axis)
and precipitation (bar graph and right vertical axis) averages for each month for some
locations on Earth.
Which climograph shows the climate for location 3?
A) B
B) C
C) D
D) E
How many electron pairs does carbon share to complete its valence shell?
A) 2
B) 3
C) 4
D) 8
Which of the following poses the best evidence that cell-signaling pathways evolved
early in the history of life?
A) Cell-signaling pathways are seen in “primitive” cells such as bacteria and yeast.
B) Bacteria and yeast cells signal each other in a process called quorum sensing.
C) Signal transduction molecules identified in distantly related organisms are similar.
D) Most signals in all types of cells are received by cell surface receptors.
Cystic fibrosis is a genetic disorder in homozygous recessives that causes death during
the teenage years. If 9 in 10,000 newborn babies have the disease, what are the
expected frequencies of the dominant (A1) and recessive (A2) alleles according to the
Hardy-Weinberg model?
A) f(A1) = 0.9997, f(A2) = 0.0003
B) f(A1) = 0.9800, f(A2) = 0.0200
C) f(A1) = 0.9700, f(A2) = 0.0300
D) f(A1) = 0.9604, f(A2) = 0.0392
If Darwin had been aware of genes and their typical mode of transmission to
subsequent generations, with which statement would he most likely have been in
agreement?
A) If natural selection can change gene frequency in a population over generations,
given enough time and genetic diversity, then natural selection can cause sufficient
genetic change to produce new species from old ones.
B) If an organism’s somatic cell genes change during its lifetime, making it more fit,
then it will be able to pass these genes on to its offspring.
C) If an organism acquires new genes by engulfing, or being infected by, another
organism, then a new genetic species will result.
D) A single mutation in a single gene in a single gamete, if inherited by future
generations, will produce a new species.
The eight climographs below show yearly temperature (line graph and left vertical axis)
and precipitation (bar graph and right vertical axis) averages for each month for some
locations on Earth.
Which climograph shows the climate for location 4?
A) A
B) C
C) E
D) G
The suprachiasmatic nuclei are found in the _____.
A) hypothalamus
B) epithalamus
C) amygdala
D) Broca’s area
What would be the best anatomical feature to look for to distinguish a gastropod from a
chiton?
A) presence of a muscular foot
B) presence of a rasp-like feeding structure
C) production of eggs
D) number of shell plates
Most of the carbon dioxide produced by humans is _____.
A) converted to bicarbonate ions by an enzyme in red blood cells
B) bound to hemoglobin
C) transported in the erythrocytes as carbonic acid
D) simply dissolved in the plasma
Fossil evidence indicates that the following events occurred in what sequence, from
earliest to most recent?
1. Protostomes invade terrestrial environments.
2. Cambrian explosion occurs.
3. Deuterostomes invade terrestrial environments.
4. Vertebrates become top predators in the seas.
A) 2 → 1 → 4 → 3
B) 2 → 4 → 1 → 3
C) 2 → 3 → 1 → 4
D) 2 → 1 → 3 → 4
A hydrocarbon skeleton is covalently bonded to an amino group at one end and a
carboxyl group at the other end. When placed in water this molecule would function
_____.
A) only as an acid because of the carboxyl group
B) only as a base because of the amino group
C) as an acid and a base
D) as neither an acid nor a base
Red-cheeked salamanders are partially protected from predators because of cardiac
glycosides they produce from glands on their back. When ingested, cardiac glycosides
disrupt normal heart rhythms. A different salamander species, the imitator salamander,
also has red cheek patches, but does not produce cardiac glycosides. It does gain
protection from predators that have learned to avoid red cheeked salamanders. How
does this relationship affect the population dynamics of both species?
A) Both species are negatively affected.
B) Both species are positively affected.
C) The red cheeked salamander is positively affected, the imitator is negatively
affected.
D) The red cheeked salamander is negatively affected, the imitator is positively
affected.
A glycosidic linkage is analogous to which of the following in proteins?
A) an amino group
B) a peptide bond
C) a disulfide bond
D) a β-pleated sheet
If plant gene alterations cause plants to be deficient in photorespiration, what would
most probably occur?
A) Photosynthetic efficiency would be reduced at low light intensities.
B) Cells would carry on the Calvin cycle at a much slower rate.
C) There would be more light-induced damage to the cells.
D) Less oxygen would be produced.
A fungal spore germinates, giving rise to a mycelium that grows outward into the soil
surrounding the site where the spore originally landed. Which of the following accounts
for the fungal movement, as described here?
A) karyogamy
B) mycelial flagella
C) breezes distributing spores
D) cytoplasmic streaming in hyphae
You find yourself standing next to a beautiful rose bush. Which of the following do you
and the rose have in common?
A) You both are multicellular.
B) You both lack a membrane-bound nucleus.
C) You are both prokaryotic.
D) You and the rose have nothing in common.
Mitochondrial DNA is primarily involved in coding for proteins needed for protein
complexes of the electron transport chain and ATP synthase. Therefore, mutations in
mitochondrial genes would most affect _____.
A) DNA synthesis in cells of the immune system
B) the movement of oxygen into erythrocytes
C) generation of ATP in muscle cells
D) the storage of urine in the urinary bladder
This nudibranch, a type of sea slug, has many reddish cerata on its dorsal surface, as
well as two white-tipped rhinophores located on the head.
The nontaxonomic term sea slug encompasses a wide variety of marine gastropods.
One feature they share as adults is the lack of a shell. We might think, therefore, that
they represent defenseless morsels for predators. In fact, sea slugs have multiple
defenses. Some sea slugs prey on sponges and concentrate sponge toxins in their
tissues. Others feed on cnidarians, digesting everything except the nematocysts, which
they then transfer to their own skins. Whereas the most brightly colored sea slugs are
often highly toxic, others are nontoxic and mimic the coloration of the toxic species.
Their colors are mostly derived from pigments in their prey. There are also sea slugs
that use their coloration to blend into their environments.
Which structure do sea slugs use to feed on their prey?
A) nematocysts
B) an incurrent siphon
C) a radula
D) a mantle cavity
Bacteria able to perform the NH4
+ + NO2
– → N2 + 2H2O reaction have been discovered
in laboratory bioreactors and wastewater treatment systems. Researchers predicted that
these bacteria should exist in oceans. They measured the concentration of NH4
+, NO2
–,
NO3
–, and O2 in the Black Sea as a function of water depth (M. Kuypers et al. 2003
Anaerobic ammonium oxidation by anammox bacteria in the Black Sea. Nature
422:608-11) to determine where in the sea the bacteria might live. Analyzing data
presented in the figure above, at what depth would you expect to find the bacteria?
(Note: In the figure, different scales are used to show concentrations of NH4
+, NO2
–,
NO3
–, and O2.)
A) in the top 50 meters
B) at a depth of 75 meters
C) at a depth of 92 meters
D) below 100 meters
Receptors for neurotransmitters are of primary functional importance in assuring
one-way synaptic transmission because they are mostly found on the _____.
A) axonal membrane
B) axon hillock
C) postsynaptic membrane
D) presynaptic membrane