What causes the shape of the molecule shown above?
A) the shape of the 2 p orbitals in the carbon atom
B) the shape of the 1 s orbital in the carbon atom
C) the shape of the sp3 hybrid orbitals of the electrons shared between the carbon and
hydrogen atoms
D) hydrogen bonding configurations between the carbon and hydrogen atoms
When a virus infects a bacterial cell, often new viruses are assembled and released
when the host bacterial cell is lysed. If these new viruses go on to infect new bacterial
cells the host cells may not be lysed. What is the most plausible explanation for this?
A) The bacterial cell must be resistant to infection by the virus.
B) The virus carries genes that confer resistance to the host bacterial cell.
C) The host bacterium couples the viral infection with transformation.
D) The virus has entered the genome of the bacterial cell and is in the lysogenic stage.
A sequence database such as GenBank could be used to do all of the following
EXCEPT
A) Compare cow and human insulin protein sequences.
B) Construct a tree to determine the evolutionary relationships between various bird
species.
C) Search for genes in a fruit fly that are similar to a human gene.
D) Compare patterns of gene expression in cancerous and non-cancerous cells.
The liver is involved in detoxification of many poisons and drugs. Which of the
following structures is primarily involved in this process and, therefore, abundant in
liver cells?
A) rough ER
B) smooth ER
C) Golgi apparatus
D) nuclear envelope
Why might researchers choose to use molecular data (such as ribosomal RNA
sequences) rather than morphological data to study the evolutionary history of animals?
A) Molecular data can be gathered in the lab, while morphological data must be
gathered in the field.
B) Sequence data can be gathered faster than morphological data, and morphological
data provides a different perspective.
C) Morphological changes usually do not result from molecular changes.
D) Some phyla vary too widely in morphological characteristics to be classified
accurately.
How is it that satellites can detect differences in primary productivity on Earth?
A) Satellite instruments can detect reflectance patterns of the photosynthetic organisms
of different ecosystems.
B) Sensitive satellite instruments can measure the amount of NADPH (nicotinamide
adenine dinucleotide phosphate) produced in the summative light reactions of different
ecosystems.
C) Satellites compare the wavelengths of light captured and reflected by
photoautotrophs in different ecosystems.
D) Satellites detect differences by measuring the amount of water vapor emitted by
transpiring producers.
The body fluids of an osmoconformer would be _____ with its _____ environment
A) isoosmotic; freshwater
B) hyperosmotic; saltwater
C) isoosmotic; saltwater
D) hypoosmotic; saltwater
The approach to estimating phylogenetic trees is most like the approach of which
species concept?
A) morphological species concept
B) biological species concept
C) phylogenetic species concept
Which of the following statements regarding turnover in a lake is correct?
A) In fall turnover, dense water at 4C sinks and disturbs sediments in the benthic zone.
B) In fall turnover, dense water at 4C rises and disturbs sediments in the benthic zone.
C) The surface water gets to 4C only by cooling.
D) Fall turnovers and spring turnovers are exactly the same.
Changes in the shape of a cell usually involve a reorganization of the _____.
A) nucleus
B) cytoskeleton
C) extracellular matrix
D) transport proteins
Compared to the seawater around them, most marine invertebrates are _____.
A) hyperosmotic
B) hypoosmotic
C) isoosmotic
D) hyperosmotic and isoosmotic
One possible use of transgenic plants is in the production of human proteins, such as
vaccines. Which of the following is a possible hindrance that must be overcome?
A) prevention of transmission of plant allergens to the vaccine recipients
B) prevention of vaccine-containing plants being consumed by insects
C) use of plant cells to translate non-plant-derived mRNA
D) inability of the human digestive system to accept plant-derived protein
Given what we know about evolutionary biology, we expect to find the largest number
of endemic species in which of the following geological features, which have existed
for at least a few million years?
A) an isolated ocean island in the tropics
B) an extensive mountain range
C) a grassland in the center of a large continent, with extreme climatic conditions
D) a shallow estuary on a warm-water coast
The following questions refer to the figure below, which shows an outcrop of
sedimentary rock whose strata are labeled A-D.
If x indicates the fossils of two closely related species, neither of which is extinct, then
their remains may be found in how many of these strata?
A) one stratum
B) two strata
C) three strata
D) four strata
Which of the following is primarily responsible for limiting the number of trophic
levels in most ecosystems?
A) Many primary and higher-order consumers are opportunistic feeders.
B) Decomposers compete with higher-order consumers for nutrients and energy.
C) Nutrient cycling rates tend to be limited by decomposition.
D) Energy transfer between trophic levels is usually less than 20 percent efficient.
A laboratory might use dideoxyribonucleotides to _____.
A) separate DNA fragments
B) produce cDNA from mRNA
C) sequence a DNA fragment
D) visualize DNA expression
Mammals and birds eat more often than reptiles. Which of the following traits shared
by mammals and birds best explains this habit?
A) endothermy
B) ectothermy
C) amniotic egg
D) terrestrial
A patient who has a high level of mast cell activity, dilation of blood vessels, and acute
drop in blood pressure is likely suffering from _____.
A) an autoimmune disease
B) a typical skin allergy (contact dermatitis) that can be treated by antihistamines
C) an organ transplant, such as a skin graft
D) anaphylactic shock immediately following exposure to an allergen
Use the survivorship curves in the figure below to answer the following questions.
Refer to the figure above. Which curve best describes survivorship in marine molluscs?
A) A
B) B
C) C
D) E
What makes sexually reproduced offspring genetically different from their parents?
A) genetic recombination during meiosis
B) genetic recombination during mitosis
C) crossing over during mitosis
D) Sexual reproduction does not produce genetically different offspring.
A researcher has developed two stains for use with seed plants. One stains sporophyte
tissue blue; the other stains gametophyte tissue red. If the researcher exposes pollen
grains to both stains, and then rinses away the excess stain, what should occur?
A) The pollen grains will be pure red.
B) The pollen grains will be pure blue.
C) The pollen grains will have red interiors and blue exteriors.
D) The pollen grains will have blue interiors and red exteriors.
From earliest to latest, the overall sequence of early development proceeds in which of
the following sequences?
A) gastrulation → organogenesis → cleavage
B) cleavage → gastrulation → organogenesis
C) gastrulation → blastulation → neurulation
D) preformation → morphogenesis → neurulation
In which of the following ways do plant hormones differ from hormones in animals?
A) Plant hormones most often travel in air as a gas.
B) Animal hormones are only local regulators.
C) Plant hormones are typically released into the soil.
D) Animal hormones are primarily for mating and embryonic development.
After suffering a stroke, a patient can see objects anywhere in front of him, but pays
attention only to objects in his right field of vision. When asked to describe these
objects, he has difficulty judging their size and distance. What part of the brain was
likely damaged by the stroke?
A) the left frontal lobe
B) the right frontal lobe
C) the left parietal lobe
D) the right parietal lobe
The main purpose of wildlife (movement) corridors is to _____.
A) slow down the introduction of new individuals of a species
B) slowly introduce a species to a new preserve
C) create more edge habitat
D) connect two otherwise isolated populations
Biologists now routinely test for homology between genes in different species. If genes
are determined to be homologous, it means that they are related _____.
A) by descent from a common ancestor
B) because of convergent evolution
C) by chance mutations
D) in function but not structure
Which of the following could be considered the most recent common ancestor of living
tetrapods?
A) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports
similar to those of terrestrial vertebrates
B) an armored, jawed placoderm with two pairs of appendages
C) an early ray-finned fish that developed bony skeletal supports in its paired fins
D) a salamander that had legs supported by a bony skeleton but moved with the
side-to-side bending typical of fishes
An individual plant was discovered that could not grow towards light. After some
research, it was determined that the reason was a defective gene that did not allow for
the level of cell elongation necessary for a phototropic response. This mutation greatly
reduces the fitness of the individual plant. Which reason best describes the reason for
the loss of fitness?
A) The plant was too short to attract insects for pollination.
B) The plant could not adjust to directional light, which reduced photosynthetic activity
and therefore energy available for reproduction.
C) Because the plant grew much taller and straighter, resources that could be used for
reproduction were used for growth.
D) The loss of a phototropic response meant that the plant’s seeds could not germinate
so reproduction would be unsuccessful.
A botanist discovers a new species of plant in a tropical rain forest. After observing its
anatomy and life cycle, he notes the following characteristics: flagellated sperm, xylem
with tracheids, separate gametophyte and sporophyte generations with the sporophyte
dominant, and no seeds. This plant is probably most closely related to _____.
A) mosses
B) ferns
C) gymnosperms
D) flowering plants
Sister chromatids separate from each other during _____.
A) meiosis I only
B) meiosis II only
C) mitosis and meiosis I
D) mitosis and meiosis II
Embryonic induction, the influence of one group of cells on another group of cells,
plays a critical role in embryonic development. In 1924, Hans Spemann and Hilde
Mangold transplanted a piece of tissue that influences the formation of the notochord
and neural tube, from the dorsal lip of an amphibian embryo to the ventral side of
another amphibian embryo. If embryonic induction occurred, which of the following
observations justifies the claim of embryonic induction?
A) The transplanted tissue induced multiple limbs to develop on the ventral side of the
recipient embryo.
B) The transplanted tissue inhibited normal cell division on the dorsal side of the
recipient embryo that lead to its death.
C) The transplanted tissue had no effect on either the ventral or dorsal side of the
recipient embryo so it continued to develop normally.
D) The transplanted tissue induced the formation of a second notochord and neural tube
on the ventral side of the developing embryo.
Use the following information to answer the question(s) below.
Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out
aerobic photosynthesis with its two elongated “chromatophores.” The chromatophores
are contained within vesicles of the host cell, and each is derived from a
cyanobacterium, though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
Previously understood similarities that seemed to connect slime molds and fungi are
now considered to be _____.
A) homologies
B) examples of convergent evolution
C) variations of common ancestral traits
D) adaptations for much different functions
In a frog embryo, gastrulation _____.
A) produces a blastocoel displaced into the animal hemisphere
B) occurs along the primitive streak in the animal hemisphere
C) proceeds by involution as cells roll over the lip of the blastopore
D) occurs within the inner cell mass that is embedded in the large amount of yolk