The last common ancestor shared by humans and chimpanzees lived about
A) 6,000-8,000 years ago.
B) 5-7 million years ago.
C) 25-40 million years ago.
D) 1.5-2.5 billion years ago.
Most CO2 is transported to the lungs in which of the following ways?
A) dissolved in the plasma
B) as carbonic anhydrase
C) as carboxyl
D) attached to hemoglobin or as bicarbonate ions
Dunaliella salina is a bacterium that is able to live in aqueous solutions with such high
salt concentrations that the salt cannot fully dissolve. D. salina is an example of a/an
A) extreme thermophile.
B) extreme halophile.
C) methanogen.
D) proteobacteria.
Mimosa plants spread their leaflets during the day and fold them at night. You decide to
design an experiment to test whether Mimosa’s leaf movements are controlled by a
biological clock. Which of the following experiments would be the best test of your
hypothesis?
A) Growing the plant indoors and turning the lights on in the middle of the night. If a
biological clock is controlling leaf movement, the leaves will open.
B) Putting the plant in a dark closet in the middle of the day. If the leaves close, a
biological clock mechanism is ruled out.
C) Subjecting the plant to a flash of red light in the middle of the night. If the leaves
open at the usual time the next morning, a biological clock mechanism is ruled out.
D) Putting the plant in a dark closet at nightfall. Check on the plant in the morning
about 10 hours later, while the plant is still in the closet. If the leaves are open, a
biological clock is indicated.
When you successfully study with the stereo on in the background, you are
demonstrating
A) habituation.
B) imprinting.
C) associative learning.
D) conditioning.
Which of the following statements regarding animals is false?
A) Animals that eat plants are called herbivores.
B) Animals that eat meat are called carnivores.
C) Animals that live in or on their food source and eat their way through it are called
filter feeders.
D) Animals that extract food particles suspended in the surrounding water are called
fluid feeders.
Which of the following produces a thick fluid containing fructose, which is used for
energy by sperm?
A) prostate gland
B) bulbourethral gland
C) seminal vesicles
D) epididymis
Which of the following statements best explains why dominant alleles that cause lethal
disorders are less common than recessive alleles that cause lethal disorders?
A) Lethal disorders caused by dominant alleles are usually more severe than lethal
disorders caused by recessive alleles.
B) Unlike lethal disorders caused by recessive alleles, lethal disorders caused by
dominant alleles usually cause the death of the embryo.
C) Most individuals carrying a lethal dominant allele have the disorder and die before
they reproduce, whereas individuals carrying a lethal recessive allele are more likely to
be healthy and reproduce.
D) The presence of a lethal dominant allele causes sterility.
The term “gene expression” refers to the
A) fact that each individual of a species has a unique set of genes.
B) fact that individuals of the same species have different phenotypes.
C) process by which genetic information flows from genes to proteins.
D) flow of information from parent to offspring.
Which of the following statements about steroid hormones is true?
A) Steroid hormones cause the production of cAMP.
B) Steroid hormones are polar molecules that cannot pass through the cell membrane.
C) Steroid hormones bind to receptors in the plasma membrane.
D) Steroid hormones bind to specific receptor proteins, and the complex acts as a gene
activator.
Unlike archaean and eukaryote cell walls, bacterial cell walls contain a unique
substance called
A) cellulose.
B) peptidoglycan.
C) phospholipid.
D) glycogen.
Traditional animal phylogenetic trees and the most recent molecular phylogenetic trees
have many similarities. Which is a feature of the recent trees that was not present in the
traditional phylogeny?
A) the placement of Echinodermata and Chordata together in a clade of deuterostomes
B) the status of sponges as the first group to diverge from the other animals
C) the grouping of nematodes and arthropods into a clade called the Ecdysozoa
D) the grouping of all bilaterally symmetric animals within a single clade
Proteins that bind to DNA and turn on operons by making it easier for RNA polymerase
to bind to a promoter are called
A) regulators.
B) operators.
C) activators.
D) repressors.
Which of the following is a potential problem with the use of transgenic varieties of
plants that contain Bt toxin?
A) Bt toxin may be harmful to humans.
B) Bt toxin may be harmful to some beneficial insects.
C) Transgenic crop varieties with Bt toxin are not very hardy and require a lot of care.
D) Transgenic crop varieties with Bt toxin require large amounts of fertilizers and
chemical insecticides to grow.
You are sitting with a friend in the park next to some children who are playing Frisbee.
You turn to talk to your friend and out of the corner of your eye you see a Frisbee
quickly approaching your face. As an innate, protective behavior, you blink your eyes.
The protective action of blinking is an example of a(n)
A) reflex.
B) integration.
C) chemical synapse.
D) neurotransmitter.
Legumes are frequently grown in rotation with primary field crops. What is the benefit
of this practice?
A) A greater amount of the primary crop can be harvested each year.
B) Nitrogen is added to the soil because of the legumes’ symbiotic nitrogen-fixing
bacteria.
C) Soil erosion is reduced by frequent plowing.
D) Legumes decrease the amount of organic material in the soil.
Iris is a long-day plant that normally flowers in the spring. Which of the following
regimens would be the most effective in making an iris bloom in late fall?
A) interrupting the plant’s nights at 2:00 am with a flash of far-red light
B) interrupting the plant’s nights at 2:00 am with a flash of red light followed by a flash
of far-red light
C) interrupting the plant’s nights at 2:00 am with a red flash, then a far-red flash, then a
red flash
D) interrupting the plant’s days at 2:00 pm by putting it in the dark
It has been suggested that global warming could be halted by fertilizing the oceans to
increase the growth of algae. How might this affect the greenhouse effect?
A) Algal photosynthesis would use up more CO2, which traps heat.
B) Algal photosynthesis would produce more O2, which blocks light.
C) Algal photosynthesis would be inhibited by the addition of fertilizer.
D) Algae photosynthesis would use heat in place of photons.
The genetically identical organisms that result from asexual reproduction are called
A) clones.
B) seeds.
C) seedlings.
D) rootlets.
Treatments for depression often include drugs that help correct imbalances in the levels
of
A) serotonin.
B) acetylcholine.
C) nitric oxide.
D) epinephrine.
The idea that all living things are composed of cells and that all cells come from other
cells defines
A) the laws of inheritance.
B) organelle theory.
C) cell theory.
D) inheritance of acquired characteristics.
For most sexually reproducing organisms, Mendel’s laws
A) cannot strictly account for the patterns of inheritance of many traits.
B) explain the biological mechanisms behind why certain genes are dominant or
recessive.
C) help us understand the global geographic patterns of genetic disease.
D) can predict whether offspring will be male or female with 100% accuracy.
A(n) ________ forms when two atoms share electrons.
A) ion
B) covalent bond
C) ionic bond
D) hydrogen bond
Chemoautotrophic bacteria obtain their carbon from ________ and their energy from
________.
A) CO2; sunlight
B) CO2; reactions involving inorganic chemicals
C) methane; sunlight
D) organic molecules; sunlight
Bats and marine mammals are well-known examples of animals that produce
high-frequency sound waves beyond the range of human hearing. The high-frequency
waves are used for echolocation, the process of emitting high-frequency sound waves
and using both the time it takes for the waves to bounce back to the caller and the
direction from which the waves return to the caller to locate distant objects. Research
has shown that bats can send and receive sounds as high as 100,000 Hertz (Hz).
On the other hand, several mammals, such as elephants and whales, produce extremely
low-frequency sounds. Elephant calls range from 5 to 50 Hz. Low-frequency sounds
have long wavelengths, which means they are less likely to be distorted or interrupted
by features in the environment. In favorable weather conditions, low-frequency sound
waves can be transmitted over several kilometers.
If you were observing two elephants separated by a distance of four miles, could the
sensory receptors of your ear receive signals passing between them?
A) Yes. Human ears have sound reception over the same range of frequencies as
elephants.
B) Yes. The organ of Corti in humans is more highly evolved than the comparable organ
in elephants.
C) No. Elephants have a much wider range of high-frequency hearing.
D) No. Human ears cannot hear sounds lower than 20 Hz.
Cystic fibrosis is a genetic disease that results from a defective CFTR protein that alters
ion flow through the cell membrane such that water does not cross the cell membrane.
Gene therapy is being used to attempt to help cystic fibrosis patients. Which of the
following steps is not needed to develop a gene therapy treatment for cystic fibrosis?
A) Clone the normal-functioning CFTR gene and make an RNA version of the gene.
B) Make antibodies to the defective CFTR protein to enhance the patient’s immune
system.
C) Remove cells from a patient and infect them with the recombinant virus.
D) Insert the RNA version of the CFTR gene into a virus.
Below is a nutrition facts label for one cup of whole cow’s milk. Which of the following
is most abundant by weight in one cup of whole milk? (1000 mg = 1 g)
A) the total amount of lipids
B) polysaccharides
C) monosaccharides
D) protein
The Calvin cycle constructs ________, an energy-rich molecule that a plant cell can
then use to make glucose or other organic molecules.
A) G3P
B) ATP
C) NADH
D) carbon dioxide
Rickets is a softening of the bones that can lead to frequent fractures and skeletal
deformities. The legs of a person with rickets tend to bow outward under the force
exerted by body weight and movement. British scientists recently found a serious
increase in the incidence of rickets and other bone deficiencies among women in
Middle Eastern countries who cover their bodies completely to express a form of
religious belief, as well as among their breast-fed children.
Most of the body’s vitamin D, which is necessary for calcium absorption by bone tissue,
is obtained through sunlight acting on the skin. Doctors warn that women who
completely cover their skin do not get enough sunlight to produce the vitamin D
necessary for bone health. This lack of sun exposure also lowers the level of vitamin D
in their breast milk, which means that their children may develop the same vitamin D
deficiencies. Lack of calcium and phosphorous, which are needed for bone repair and
replacement, can also lead to rickets. Rickets caused by a dietary lack of these minerals
is more common in developing countries because dairy products and green vegetables,
the best sources of calcium, are not commonly eaten.
As a physician caring for a nursing woman who has chosen to dress in a way that
covers her skin but who is concerned about rickets developing in her baby, you might
advise her to
A) exercise more.
B) eats lots of meat and potatoes.
C) take vitamin D and calcium supplements.
D) give up smoking.
Yeast are able to communicate with each other
A) by close cell-to-cell contact.
B) through chemical signaling.
C) only if they can touch each other and have merged cell walls.
D) with pseudopodia.
RNA splicing involves the
A) addition of a nucleotide “cap” to the molecule.
B) addition of a nucleotide “tail” to the molecule.
C) removal of introns from the molecule.
D) removal of exons from the molecule.
The energy yield from the breakdown of a single molecule of glucose does not depend
upon
A) whether the NADH produced in glycolysis passes its electrons across the
mitochondrial membrane to NAD+ or FAD.
B) the supply of oxygen.
C) the supply of carbon dioxide.
D) whether some of the energy of the H+ gradient is used for work other than ATP
production.
An owl and a hawk both eat mice. Which of the following describes the relationship
between a hawk and an owl?
A) predation
B) competition
C) mutualism
D) parasitism
An organism that can fly and has an exoskeleton must be
A) a member of the Chordata.
B) an echinoderm.
C) an insect.
D) a polychaete.
Which of the following organisms is a marsupial?
A) echidna
B) kangaroo
C) whale
D) zebra