Textile mills often release dye color and toxic by-products into rivers and streams,
which may then taint groundwater. Fungi associated with mangrove trees have been
shown to reduce both colors and toxicity in tainted groundwater.
Suppose that in 1990, fungal treatment was added to stream water contaminated from a
textile mill. The toxins in the water tend to lower pH levels, and scientists wanted to
study how adding the fungal treatment affected stream pH levels. pH levels were
recorded every year for five years. Results indicated that the acidity of the stream water
decreased from pH 2.5 in the first year to pH 5.9 by the fifth year. Scientists concluded
that
A) the fungal treatment had little to no effect on detoxifying the stream water.
B) the fungal treatment had a positive effect on detoxifying the stream water.
C) the fungal treatment had completely detoxified the stream water.
D) there was not enough evidence to determine the effects of the fungal treatment on
the toxic stream water.
The flow of ________ into ecosystems occurs in one direction only, while ________
are recycled within the ecosystem itself.
A) minerals; energy compounds
B) genetic information; genotypes
C) organic compounds; minerals
D) energy; chemicals
The molecules responsible for membrane transport are
A) steroids.
B) phospholipids.
C) carbohydrates.
D) proteins.
What is the advantage of excreting nitrogenous waste in the form of ammonia?
A) Ammonia is less toxic than uric acid.
B) Ammonia is less soluble than uric acid.
C) Ammonia excretion conserves energy.
D) Ammonia does not diffuse across cell membranes.
A skin cell of a red fox has 34 chromosomes. You look at the cell under a microscope
and see that it has 34 chromosomes and one nucleus. Several hours later, you look at the
same cell again and see that it has double the amount of DNA and one nucleus. A little
while later, you see that it has 68 chromosomes and two nuclei. What stage of the cell
cycle was this cell in when you viewed it at each time point?
A) First view: G1; second view: G2; third view: telophase
B) First view: G1; second view: metaphase; third view: cytokinesis
C) First view: S; second view: prophase; third view: cytokinesis
D) First view: G0; second view: G2; third view: telophase
Which of the following activities would result in a decrease in your ecological
footprint?
A) flying across the United States once a month
B) driving your car to and from school every day
C) leaving the water running while you brush your teeth
D) taking a city bus instead of driving to work
In which part of the human female reproductive system does implantation normally
take place?
A) part A
B) part B
C) part C
D) part D
Mutations in the gene for troponin can result in the production of the troponin protein,
which has varying affinities for Ca2+ ions. Suppose that in a muscle cell a mutant
troponin is expressed that has such a high affinity for Ca2+ ions that once they bind to
troponin they cannot unbind. What will likely happen in this muscle cell?
A) Myosin heads will not bind to actin after action potentials stop being received.
B) Myosin heads will bind to actin after action potentials stop being received.
C) Tropomyosin will not move to expose myosin binding sites.
D) Cross-bridges will form between myosin and tropomyosin.
Which of the following statements regarding spermatogenesis and oogenesis is true?
A) Meiosis in spermatogenesis produces two cells from one primary spermatocyte.
B) Meiosis in oogenesis produces one mature egg from one primary oocyte.
C) Oogenesis begins at puberty.
D) Spermatogenesis begins at birth.
Mendel’s law of independent assortment states that
A) chromosomes sort independently of each other during mitosis and meiosis.
B) independent sorting of genes produces polyploid plants under some circumstances.
C) each pair of alleles segregates independently of the other pairs of alleles during
gamete formation.
D) genes are sorted concurrently during gamete formation.
The oxygen-carrying component in red blood cells is
A) hemoglobin.
B) bicarbonate ions.
C) iron.
D) the cell membrane.
If you were able to stop the process of cellular respiration after completing electron
transport but prior to chemiosmosis, you would find the pH of a mitochondrion to be at
its lowest
A) on the outer membrane.
B) on the inner membrane.
C) in the mitochondrial matrix.
D) in the intermembrane space.
In examining the effects of atrazine, one of the most commonly used herbicides in the
world, scientists studied the mating behavior of male frogs exposed to atrazine (Atr)
compared to a group that was not exposed (Non). The results are shown in the figure.
The experiment in part A was important to the overall conclusions by demonstrating all
of the following except
A) all trials of the experiment had frogs of about the same size.
B) there is variation in body weight.
C) body size did not have an impact on successful mating.
D) frogs gain weight over time.
A population of fungi in a yard produces 10 mushrooms in year 1, 20 in year 2, and 40
in year 3. If this trend continues, by year 5 there will be ________ mushrooms.
A) 40
B) 80
C) 160
D) 320
The nucleus of a cell
A) is surrounded by a single layer of membrane.
B) is contained within the nucleolus.
C) contains DNA.
D) is the primary location of protein synthesis.
A physician friend of yours is telling you about a patient with a head injury who
suddenly stopped breathing. Your friend explains that the bony rim was pressing against
the breathing center. You guess that the “bony rim” (whatever that is) must have been
exerting pressure in the region of the
A) basal ganglia and hippocampus.
B) cerebellum and cerebrum.
C) thalamus and hypothalamus.
D) medulla oblongata and pons.
Researchers set up a study to determine whether large doses of a nutritional supplement
would shorten the length of time it takes to recover from a cold. Three thousand
volunteers were split into two groups. For two weeks, members of group A took 3,000
mg of the supplement daily. Group B received 3,000 mg of a placebo. At the end of the
two-week period, the researchers inserted live cold viruses directly into the noses of all
the volunteers. The volunteers in both group A and group B continued to take their daily
pills. All the volunteers got colds, and there was no significant difference in the length
of time the colds lasted.
To have confidence that the results of the experiment were valid, you’d also want to
know
A) whether any volunteers had colds at the start of the experiment.
B) whether the volunteers exercised daily.
C) whether the volunteers all worked for the same company.
D) what the volunteers ate during the experiment.
Dr. Smith’s parents have normal hearing. However, Dr. Smith has an inherited form of
deafness. Deafness is a recessive trait that is associated with the abnormal allele d. The
normal allele at this locus, associated with normal hearing, is D. Dr. Smith’s parents
could have which of the following genotypes?
A) DD and dd
B) dd and dd
C) Dd and Dd
D) Dd and DD
Two species interbreed occasionally and produce vigorous, fertile hybrids. When the
hybrids breed with each other or with either parent species, however, the offspring are
feeble or sterile. These species are affected by
A) gametic isolation.
B) reduced hybrid fertility.
C) reduced hybrid viability.
D) hybrid breakdown.
Based on von Frisch’s work on honeybee communication, which of the following types
of information is communicated to other workers by a honeybee’s “dance”?
A) the direction of the nectar source
B) the distance of the nectar source from the nearest water
C) the color of the flowers producing the nectar
D) the quality of the nectar
You are driving at night and decide to pass a slow-moving car. As you look at the car as
you pass, it dawns on you that although you can see the car, you can’t tell what color it
is. This is due to
A) the poor ability of cones to function in low light.
B) the poor ability of rods to function in low light.
C) a reduced ability to focus in low light situations.
D) the constriction of your pupil in low light situations, which reduces color vision.
During the process of electrophoresis, the ________ functions like a molecular sieve,
separating the samples according to their size.
A) sample mixture
B) positively charged electrode
C) negatively charged electrode
D) agarose gel
Several primates have been taught to communicate with humans using sign language.
This supports the view that animals other than humans can learn through the process of
A) social learning.
B) cognition.
C) trial-and-error learning.
D) imprinting.
Which of the following tundra features can be found at the top of the Andes Mountains
in Ecuador?
A) fierce winds and frigid nights
B) permafrost
C) large trees with shallow roots
D) a brief, bright growing season and a long, dark winter
Small pieces of RNA that can regulate translation of mRNA are called
A) microRNA.
B) interfering RNA.
C) transfer RNA.
D) messenger RNA.
Which of the following statements regarding mitosis and meiosis is false?
A) Meiosis only occurs in the ovaries and testes.
B) All sexual life cycles involve an alternation of diploid and haploid stages.
C) Mitosis produces daughter cells with half the number of chromosomes as the parent
cell.
D) A normal human zygote has 46 chromosomes.
If one strand of DNA is CGGTAC, then the corresponding strand would be
A) GCCTAG.
B) GCCAUC.
C) TAACGT.
D) GCCATG.
A researcher is investigating the ability of salmon to migrate thousands of miles in the
ocean yet return to the location where they were hatched to spawn. Data from
experiments suggest that more than one type of homing mechanism may be involved in
this behavior. When salmon arrive at a river mouth from the open sea, they appear to
use olfactory cues to find their home streams, but how do they find their way back to
the correct spot along the coastline from the open ocean?
Several experiments were carried out to test the hypothesis that geomagnetic factors
(the influence of Earth’s magnetic field) play a key role in the ability of salmon to find
the proper location along the coast. In one such experiment, salmon hatched in
Ketchikan, Alaska were subjected to the geomagnetic characteristics of a different
location on the Alaska Peninsula, Cold Bay. The fish were then released to determine to
which of the two locations they would return to spawn.
What type of behavior would explain the ability of the salmon to return to their home
streams?
A) imprinting
B) associative learning
C) social learning
D) habituation
Most bats are inactive during the day (this is known as torpor) and feed during the
night. The graph below shows hypothetical data for a bat species.
Based on this graph, what is the relationship between metabolic rate and body
temperature?
A) When metabolic rate drops, so does body temperature.
B) When metabolic rate drops, body temperature rises.
C) When metabolic rate drops, body temperature remains constant.
D) There is no relationship between metabolic rate and body temperature.
________ cells lack a membrane-enclosed nucleus.
A) Plant
B) Prokaryotic
C) Eukaryotic
D) Fungal