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A nonfunctional CD4 protein on a helper T cell would result in the helper T cell being
unable to _____.
A) respond to T-independent antigens
B) lyse tumor cells
C) stimulate a cytotoxic T cell
D) interact with a class II MHC-antigen complex
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.
You are given the task of designing an aerobic, mixotrophic protist that can perform
photosynthesis in fairly deep water (for example, 250 meters deep) and can also crawl
about and engulf small particles. With which two of the following structures would you
provide your protist?
1. hydrogenosome
2. apicoplast
3. pseudopods
4. chloroplast from red alga
5. chloroplast from green alga
A) 1 and 2
B) 2 and 3
C) 3 and 4
D) 4 and 5
If a person loses a large amount of water in a short period of time, he or she may die
from dehydration. Antidiuretic hormone (ADH) can help reduce water loss through its
interaction with its target cells in the _____.
A) anterior pituitary
B) posterior pituitary
C) bladder
D) kidney
Use the following information to answer the questions below.
A spaceship is designed to support animal life for a multiyear voyage to the outer
planets of the solar system. Plants will be grown to provide oxygen and to recycle
carbon dioxide. Since the spaceship will be too far from the sun for photosynthesis, an
artificial light source will be needed.
Suppose a plant has a unique photosynthetic pigment and the leaves of this plant appear
to be reddish yellow. What wavelengths of visible light are absorbed by this pigment?
A) red and yellow
B) blue and violet
C) green and yellow
D) blue, green, and red
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 location of fossils of two closely related species, then fossils of their
most-recent common ancestor are most likely to occur in which stratum?
A) A
B) B
C) C
D) D
In which of the following would there be the greatest need for osmoregulation?
A) an animal connective tissue cell bathed in isotonic body fluid
B) a salmon moving from a river into an ocean
C) a red blood cell surrounded by plasma
D) a plant being grown hydroponically in a watery mixture of designated nutrients
A vasectomy _____.
A) eliminates spermatogenesis
B) eliminates testosterone synthesis
C) prevents implantation of an embryo
D) prevents sperm from exiting the male urethra
Mendel continued some of his experiments into the F2 or F3 generation to _____.
A) obtain a larger number of offspring on which to base statistics
B) observe whether or not a recessive trait would reappear
C) observe whether or not the dominant trait would reappear
D) distinguish which alleles were segregating
One way to detect alternative splicing of transcripts from a given gene is to _____.
A) compare the DNA sequence of the given gene to that of a similar gene in a related
organism
B) measure the relative rates of transcription of the given gene compared to that of a
gene known to be constitutively spliced
C) compare the sequences of different primary transcripts made from the given gene
D) compare the sequences of different mRNAs made from the given gene
In the thylakoid membranes, the pigment molecules in a light-harvesting complex
_____.
A) split water and release oxygen from the reaction-center chlorophyll
B) absorb and transfer light energy to the reaction-center chlorophyll
C) synthesize ATP from ADP and i
D) transfer electrons to ferredoxin and then NADPH
What is present in a shoot apical meristem region?
I) the region of cell division
II) immature buds and leaves
III) cells that will give rise to the protoderm, ground meristem, and procambium
A) only I
B) only II
C) only III
D) I, II, and III
Logically, which of these should cast the most doubt on the relationships depicted by an
evolutionary tree?
A) Some of the organisms depicted by the tree had lived in different habitats.
B) The skeletal remains of the organisms depicted by the tree were incomplete (in other
words, some bones were missing).
C) Transitional fossils had not been found.
D) Relationships between DNA sequences among the species did not match
relationships between skeletal patterns.
The soil layer surrounding plant roots, called the rhizosphere, has been shown in some
cases to _____.
A) contain fungi that produce an endotoxin which inhibits the growth rhizomes
B) inhibit the growth of fungal pathogens
C) produce vitamins essential for the uptake of nitrogen
D) contain archaea which produce antibiotics that prevent the growth of most bacteria
Air masses formed over the Pacific Ocean are moved by prevailing westerlies where
they encounter extensive north-south mountain ranges, such as the Sierra Nevada and
the Cascades. Which statement best describes the outcome of this encounter between a
landform and an air mass?
A) The cool, moist Pacific air heats up as it rises, releasing its precipitation as it passes
the tops of the mountains. This warm, now dry air cools as it descends on the leeward
side of the range.
B) The warm, moist Pacific air rises and cools, releasing precipitation as it moves up
the windward side of the range. This cool, now dry air mass heats up as it descends on
the leeward side of the range.
C) The cool, dry Pacific air heats up and picks up moisture from evaporation of the
snowcapped peaks of the mountain range, releasing this moisture as precipitation when
the air cools while descending on the leeward side of the range.
D) These air masses are blocked by the mountain ranges, producing high annual
amounts of precipitation on the windward sides of these mountain ranges.
Use the following information to answer the questions below.
A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the
enzyme that converts X to Y at a position remote from its active site. This binding
decreases the activity of the enzyme.
The mechanism in which the end product of a metabolic pathway inhibits an earlier step
in the pathway is most precisely described as _____.
A) metabolic inhibition
B) feedback inhibition
C) allosteric inhibition
D) noncooperative inhibition
Healthy corals are brightly colored because they _____.
A) secrete colorful pigments to attract mates
B) host symbionts with colorful photosynthetic pigments
C) build their skeletons from colorful minerals
D) secrete colorful pigments to protect themselves from ultraviolet light
In animals, nitrogenous wastes are produced mostly from the catabolism of _____.
A) starch and cellulose
B) triglycerides and steroids
C) proteins and nucleic acids
D) phospholipids and glycolipids
Increases and decreases of the heart rate result from changes in the activity of the
_____.
A) medulla oblongata
B) thalamus
C) pituitary
D) cerebellum
What soil composition would be best for availability of nutrients, water, and root
development?
A) equal amounts of sand, clay, and humus
B) higher proportion of humus, lower amounts of clay and sand
C) higher proportion of clay, lower amounts of humus and sand
D) higher proportion of sand, lower amount of humus and clay
Use the following information to answer the question(s) below.
There is much discussion in the media about protecting biodiversity. But does
biodiversity really matter? Canadian and Swiss researchers wanted to know if the
diversity of arbuscular mycorrhizal fungi (AMF) was important to the productivity of
grasslands (M.G.A. van der Heijden, J. N. Klironomos, M. Ursic, P. Moutoglis, R.
Streitwolf-Engel, T. Boler, A. Wiemken, and I. R. Sanders. 1998. Mycorrhizal fungal
diversity determines plant biodiversity, ecosystem variability and productivity. Nature
396:69-72). Specifically, they wanted to know if it mattered which specific AMF
species were present, or just that some type of AMF was present. They grew various
plants in combination with one of four AMF species (A, B, C, and D), no AMF species
(O), or all four AMF species together (A+B+C+D); and they measured plant growth
under each set of conditions. All plant species were grown in each plot, so they always
competed with each other with the only difference being which AMF species were
present.
On the graphs below, the x-axis labels indicate the number and identity of AMF species
(bar 0 = no fungi; bars A-D = individual AMF species; bar A+B+C+D = all AMF
species together). The y-axis indicates the amount (grams) of plant biomass for the
species shown in italics above each graph.
If all fungi in an environment that perform decomposition were to suddenly die, then
which group of organisms should benefit most, due to the fact that their fungal
competitors have been removed?
A) flowering plants
B) protists
C) prokaryotes
D) grasses
Why do skates and rays have flattened bodies, while sharks are torpedo shaped?
A) Sharks are more closely related to the tubelike lampreys than skates and rays are.
B) Skates and rays need enlarged pectoral fins to help them stay level in turbulent
water, while sharks do not.
C) Skates and rays exchange gases across their skin and thus require a high
surface-area-to-volume ratio, while sharks use gills to respire.
D) Sharks are streamlined for active swimming off the bottom, while skates move about
mostly on the ocean bed.
What is the function of reverse transcriptase in retroviruses?
A) It uses viral RNA as a template for DNA synthesis.
B) It converts host cell RNA into viral DNA.
C) It translates viral RNA into proteins.
D) It uses viral RNA as a template for making complementary RNA strands.
The spiracles and tracheae of insects have a function most similar to that of _____.
A) rhinophores
B) dorsal plummules
C) cerata.
D) chemoreceptors
Use the following information to answer the question(s) below.
Brown et al. and Morwood et al. reported in 2004 that they had found skeletal remains
of a previously unknown type of hominin, now dubbed Homo floresiensis, on the
Indonesian island of Flores. These hominins were small (approximately 1 meter tall)
with small braincases (approximately 380 cubic centimeters) as compared with other
hominins. The remains of H. floresiensis were found alongside handmade stone tools
and the remains of dwarf elephants that also inhabited the island, suggesting that H.
floresiensis was able both to make tools and to coordinate the hunting of animals much
larger than itself. H. floresiensis is estimated to have lived at the site where the remains
were found from at least 38,000 years ago to 18,000 years ago.
The table above is a comparison of several characteristics of H. floresiensis to those of
nine other hominin species (arranged roughly from oldest to most recent). What do
these data suggest?
A) A large brain is not necessarily required for toolmaking.
B) Body mass and braincase volume are completely unrelated.
C) Hominins first evolved in and then radiated out from Asia.
D) Homo floresiensis is most closely related to Australopithecus afarensis or A.
africanus.
The solutions in the two arms of this U-tube are separated by a membrane that is
permeable to water and glucose but not to sucrose. Side A is half-filled with a solution
of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose.
Initially, the liquid levels on both sides are equal.
Refer t o the figure. Initially, in terms of tonicity, the solution in side A with respect to
the solution in side B is _____.
A) hypotonic
B) isotonic
C) saturated
D) hypertonic
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.
Including the membrane of the surrounding vesicle, how many phospholipid (NOT
lipopolysaccharide) bilayers should be found around each P. chromatophora's
chromatophore, and which one of these bilayers should have photosystems embedded
in it?
A) two; innermost
B) two; outermost
C) three; innermost
D) three; outermost
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
Which of the following would increase the rate of heat exchange between an animal
and its environment?
A) feathers or fur
B) vasoconstriction
C) wind blowing across the body surface
D) blubber or fat layer
The pattern of embryonic development in which only the cells lacking yolk
subsequently undergo cleavage is called _____.
A) holoblastic development, which is typical of marsupial mammals
B) meroblastic development, which is typical of humans
C) holoblastic development, which is typical of amphibians
D) meroblastic development, which is typical of birds
The process of obtaining food is known as _____ and requires specialized mouthparts.
A) ingestion
B) digestion
C) absorption
D) excretion
Planarians lack dedicated respiratory and circulatory systems because _____.
A) none of their cells are far removed from the gastrovascular cavity or from the
external environment
B) they lack mesoderm as embryos and, therefore, lack the adult tissues derived from
mesoderm
C) their flame bulbs can carry out respiratory and circulatory functions
D) their body cavity, a pseudocoelom, carries out these functions
