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What enzyme does HIV use to convert RNA to DNA? - ANSWER-Reverse Transcriptase The promoter region of a prokaryotic gene is located ______ to the gene and is the binding site for ______. - ANSWER-5'...RNA polymerase Which of the following is TRUE of prokaryotes? I. Simultaneous transcription and translation II. Presence of intron sequences III. Circular DNA - ANSWER-I and III only Integral transmembrane proteins are proteins imbedded in the cell membrane. Which of the following amino acids would you MOST expect to find in the transmembrane region of such proteins? - ANSWER-Tryptophan When the base composition of DNA from bacterium Mycobacterium tuberculosis was determined, 18% of the bases were found to be adenine. What is the G + C content in M. tuberculosis? - ANSWER-64% The frequency of individuals affected with an autosomally recessive inherited disorder is 1 in 4. Assuming that the population affected by this disease is in
Hardy-Weinberg equilibrium, what is the proportion of carrier individuals in this population? - ANSWER-50% The velocity of action potential conduction across a nerve axon is increased by the presence of the myelin sheath. In the peripheral nervous system, what cell myelinates the axon? - ANSWER-schwann cell The cell bodies of afferent (sensory) nerves involved in somatic reflexes are located in the - ANSWER-Dorsal root ganglion Rods and cones are associated with _____ and _____ vision, respectively. - ANSWER-Light/dark...color Populations that are likely to be living at a density near the limit of their resources, are characterized as - ANSWER-K-selected In many types of cancer, the function of the p53 gene is lost. Wild-type p53 is MOST likely to be a - ANSWER-tumor suppressor What glycolytic product is shuttled to the mitochondria in aerobic respiration? - ANSWER-Pyruvate During human development, which process leads to the formation of three germ layers? - ANSWER-gastrulation Telomerase is responsible for _____ the size of telomeres, and its function is often ____ in carcinogenesis. - ANSWER-maintaining ... increased
Which two functional groups are always found in amino acids? - ANSWER- Carboxyl and amine Movement of ions across the membrane from higher to lower concentrations through a channel protein is an example of - ANSWER-Facilitated diffusion Which group of plants has vascular tissue but does not produce seeds? I. Mosses II. Ferns III. Gymnosperms - ANSWER-II Which of the following is true for transport in xylem? - ANSWER-Movement through xylem depends mainly on transpiration Predation is considered a _________ interaction, while Mutualism is considered a ___________ interaction. - ANSWER-+/-, +/+ Which of the following organisms is INCORRECTLY paired with its trophic level?
- ANSWER-Beetle - secondary consumer Which of the following is an example of habituation? - ANSWER-Hydra initially contract when gently touched, but soon stop responding. Suppose gene "C" is the gene for color. Its dominant allele has the effect of allowing the production of fur color while its recessive allele interrupts color production. At another locus, there exists another gene that influences color, at
which black (B) is dominant to brown (b). What is the relationship between these genes called? - ANSWER-Epistatic During migrations, some birds use which of the following as reference frameworks? I. The sun II. Constellations III. Earth's magnetic field - ANSWER-I,II, and III Generally, there are more species per square kilometer in which of the following types of ecosystem? - ANSWER-Coral reef RUBP is used and PGA is formed in: - ANSWER-dark reaction (Calvin cycle) of photosynthesis Which is TRUE of the dark reaction (Calvin cycle) of photosynthesis? - ANSWER-It uses carbon dioxide In the fern life cycle, the dominant generation is the: - ANSWER-diploid sporophyte Assume a person is placed on cortisol medication, a glucocorticoid. How would you expect the rates of ACTH and CRF hormone production to change in the person? - ANSWER-ACTH production would decrease, CRF production would increase
You examine a leaf cross-section under a microscope and find many loosely packed cells. These cells have many chloroplasts and relatively thin cell walls. These cells are: - ANSWER-Parenchyma For the biomass pyramid shown below, choose the correct statement. secondary consumer primary consumer producer (see question 11 on 2004 exam)
- ANSWER-Producers reproduce quickly but are also consumed at a rapid rate Which of the following would be most likely to increase competition among the members of the vole population in a given area? - ANSWER-An increase in the reproduction rate of voles Tobacco mosaic virus has RNA rather than DNA as its genetic material. If the RNA genome from a tobacco mosaic virus is mixed with proteins from a human rhinovirus, the result is a mixed virus. If that virus could infect a cell and reproduce, what would you expect the resulting viruses to be like? - ANSWER- Tobacco Mosaic Virus An amphipathic molecule is a molecule that is characterized by: - ANSWER-A hydrophilic end and a hydrophobic end The function of a molecular chaperone is to - ANSWER-bind to specific structures on the polypeptide in order to assist the folding of a protein into its correct three dimensional shape. Ethidium Bromide is used in electrophoresis of DNA fragments because it: - ANSWER-makes the fragments visible under UV light.
The species Homo sapiens first appeared in which geologic epoch? - ANSWER- Pleistocene Which of the following marine communities would be LEAST affected by a volcanic eruption or meteor impact that injected enough debris into the atmosphere to reduce sunlight by 50% for two years? - ANSWER-Deep sea vent community A unique feature of fertilization in angiosperms is that: - ANSWER-it is a double fusion event; one sperm fertilizes the egg, the other sperm combines with the polar or fusion nucleus. Which statement describing plant structure is appropriate? - ANSWER- Sclerenchyma cells provide support for the plant body The Hardy-Weinberg equilibrium principle assumes all of the following statements EXCEPT: - ANSWER-. for a given trait the frequency of dominant alleles is greater than that of recessive alleles. Professor Jones is running an experiment with his graduate students in his physiology lab. One group of students drinks a liter of water, another group drinks a liter of coffee, and a third group drinks a liter of concentrated salt solution. The volume of urine produced by all individuals in the three groups is measured over a period of several hours. At the end of the monitoring period, which group will have produced the greatest volume of urine and which group the least? - ANSWER- Those who drank coffee will produce the most urine, while those who drank the salt solution will produce the least A protein is usually tagged for degradation by proteasome activity by which of the following proteins? - ANSWER-Ubiquitin
Which of the choices below correctly ranks [from least to greatest] the contribution of the various ecosystems as to their "Average Net Primary Production per unit area (kcal/m2/yr)"? - ANSWER-Open ocean, savanna, temperate forest, tropical rain forest In most terrestrial mammalian species, parental investment is greater for female parents than for male parents. This is because: - ANSWER-females are typically 'K-selected', whereas males are more often 'r-selected'. Which of the following is part of the egg-producing structure in plants? - ANSWER-The megagametophyte of angiosperms A booster dose of a vaccination helps to: - ANSWER-increase the blood antibody level by increasing the number of effector cells. In mice, one gene regulates color. Homozygous recessive organisms are white, homozygous dominant organisms are black, and some organisms exhibit incomplete dominance (gray fur). A gray male and a gray female produce an offspring of unknown gender. What is the probability that the mouse will NOT be born with white fur? - ANSWER-3/ The most phytoplankton in a lake would be found in which zone? - ANSWER- Limnetic Zone Hemoglobin, an iron-containing protein in erythrocytes, binds oxygen molecules. Myoglobin, a protein in muscle cells, is used for oxygen storage. What can be deduced about the relative oxygen affinities of hemoglobin and myoglobin? - ANSWER-. Myoglobin has greater oxygen affinity than hemoglobin
In an experiment, a plant is grown at a particular level of light and in a certain concentration of CO2. With CO2 constant and light intensity gradually increasing to a preset level, oxygen production increases up to a point and then levels off. If light is increased beyond the preset level, no further increase in oxygen production is noted. In a second experiment, the same increasing regimen of light is used, but a higher level of CO2 is supplied. O2 production in the second experiment continues to increase beyond the point where it leveled off in the first experiment. From these observations, one might conclude: - ANSWER-light is limiting up to a point and then CO2 becomes a limiting factor. Plant systematicists have found that monocots were not the first flowering plants to evolve. This would suggest that: - ANSWER-evolution does not always proceed from simple to complex. In a certain population of 100 deer, 34 births and 25 deaths were recorded in one year. Assuming no immigration or emigration occurred, what is r for that population? - ANSWER-0. A patient is suffering from kidney failure. Which of the following symptoms will most likely be present in this patient? - ANSWER-A higher salt concentration in the blood An investigator found 150 different diatom species in one mile of a stream. None of the species comprised more than 5% of the total population. In a second observation twenty-five miles downstream, there were only 20 different diatom species, with 2 species representing 80% of the total population. What is the best explanation of these two observations? - ANSWER-Organic wastes high in nitrates and phosphates entered the stream somewhere between the two sampling stations
Vascular plants share all of the following characteristics EXCEPT: - ANSWER- development of seeds. The production of the genetically engineered "golden rice" could be important to the people of developing nations, especially in South-East Asia, because: - ANSWER-golden rice contains higher concentrations of β-carotene than white rice A large population of laboratory rats was allowed to breed randomly for a number of generations. In this population, a dominant allele at the A locus codes for agouti fur (A), and a recessive allele codes for black fur (a). At the beginning of the breeding cycles, 49% of the rats had black fur. At the end of the breeding cycles, this percentage was the same. The rest of the animals had agouti fur with heterozygotes indistinguishable from homozygous dominants. What percentage of this population is probably heterozygous for the fur color trait assuming the rats are following Hardy-Weinberg population genetics? - ANSWER-42% In Pompe's disease, the liver is damaged due to the accumulation of glycogen. What organelle is most likely malfunctioning? - ANSWER-lysosome Transport of which nutrient across the intestinal epithelium is by passive diffusion?
- ANSWER-fructose Which two brain centers control mammalian respiration? - ANSWER-medulla oblongata and pons The presence of a vertebral column is with respect to all vertebrates [first term], but is with respect to all chordates [second term]. - ANSWER-primitive; derived
The main explanation for the lack of a continuing abiotic origin of life on Earth today is that: - ANSWER-our oxidizing atmosphere is not conducive to spontaneous formation of complex molecules Scientists have determined that three classes of genes (named A, B, and C) control development of the four flower parts: Sepals, Petals, Stamen, and Carpels. Genes A and C mutually repress each other. Gene B is not regulated by either Genes A or C. The expression pattern of these genes in wild-type flowers is shown below, where +++ indicates gene activity. A mutation in Gene C, which prevents its expression, will result in which of the following floral patterns? (question 8 of 2005 exam) - ANSWER-Sepals-Petals- Petals-Sepals An inbred strain of plants has a mean height of 24 cm. A second strain of the same species also has a mean height of 24 cm. When these plants are crossed, the F1 are also 24 cm. However, when the F1 plants are crossed, the F2 plants show a wide range of heights; the majority of F2 are like P1 and F1, but approximately 4 of 1000 are only 12 cm tall and 4 of 1000 are 36 cm tall. What fraction of the F plants will be 27 cm in height? [Assume that for the genes involved in determining plant height, each allele contributes the same amount.] - ANSWER-56/ To be functional, a linear chromosome most often contains at least: - ANSWER- two telomeres, one centromere, and a large number of origins of replication Which of the following subdivisions of the autonomic nervous system would be most important to a zebra fleeing from a lion? - ANSWER-the sympathetic nervous system To keep their dog breeds "pure," breeders will keep dogs of different breeds in physically separate areas when the female is in heat. This aspect of artificial
In plant cells grown in the presence of a metabolic poison that specifically inhibits mitochondrial F1ATP synthase, one would expect: - ANSWER-the overall pH difference across the cristae to be altered Convergent evolution produces ________. - ANSWER-analogous structures The fluidity of a lipid bilayer is enhanced with: - ANSWER-increased unsaturation in fatty acid tails Elevation of the patient's eosinophil count may reflect infection by which of the following organisms? - ANSWER-schistoma The strongest evidence for the endosymbiotic origin of eukaryotic organelles is the similarity between: - ANSWER-some prokaryotes and mitochondria By convincing soldiers that they are part of a "brotherhood," which increases the likelihood that they will protect and die for each other, the military is—consciously or unconsciously—tapping into genes that were adaptive in our ancestors because of: - ANSWER-kin selection A red pigment is extracted from a marine alga. Which best supports the hypothesis that the pigment is involved in photosynthesis? The red pigment: - ANSWER-has an absorption spectrum similar to the photosynthetic action spectrum for that same marine alga
Given the following pedigree: What is (are) the possible mode(s) of inheritance? I. Autosomal dominant II. Autosomal recessive III. X-linked dominant IV. X-linked recessive (question 25 of 2005 exam) - ANSWER-II or IV only Color-blindness is a recessive, X-linked trait. A couple, who are both blood type A and who both have normal vision, have a son who is blood type O and colorblind. What is the probability that their next child will be a daughter who is blood type O and has normal vision? - ANSWER-1/ A strain of bacteria living in a hospital is found to have a plasmid containing two genes: one for sex pilus construction, and one for tetracycline resistance. If these bacteria were to undergo conjugation with bacteria lacking this plasmid, and thus transferred the plasmid to the other bacteria, the most likely result would be: - ANSWER-rapid spread of tetracycline resistance to other bacteria in the hospital How do Aspirin and Ibuprofen produce anti-inflammatory effects? - ANSWER-by inhibiting prostaglandin synthesis Group hunting can favorably influence the ability to obtain different food resources and the efficiency of a capture as a result of: - ANSWER-increased chance of capturing larger prey A fruit with an endocarp composed of sclerenchyma cells, but fleshy mesocarp and exocarp, is called a: - ANSWER-drupe Most of today's biological diversity has arisen via: - ANSWER-cladogenesis
Net primary productivity, in most ecosystems, is important because it represents the: - ANSWER-storage of chemical energy that would be available to heterotrophs In general, where are the vessels found in "ring porous wood?" - ANSWER-in the spring wood Terminally differentiated cells are most often found in which phase of the cell cycle? - ANSWER-G During the first 6 to 8 weeks of gestation, the principal source of estrogen and progesterone is: - ANSWER-corpus luteum There is evidence that anadromous migration - from ocean to headwaters of rivers - by fish such as Salmo salmon: - ANSWER-probably derives from a trophic adaptation in freshwater fishes Insulin release results in all of the following physiological effects EXCEPT: - ANSWER-decreased glycogen stores in liver cells The endosperm of a plant with "monosporic" development has 72 chromosomes. How many chromosomes does the egg cell have? - ANSWER- 24 An allergic reaction is caused by an antigen with this class of immunoglubin: - ANSWER-IgE
What effect do sexual processes (meiosis and fertilization) have on allele frequencies in a population? - ANSWER-They have no direct effect on allele frequencies. A mutation in the gene encoding cyclin D: - ANSWER-A,B, or C The velocity of carrier-mediated diffusion across cellular membranes: - ANSWER- can increase up to a maximum value Insulin injected by diabetics to control blood sugar levels is derived from bacteria whose DNA has been modified by the addition of the human gene for insulin, which is then produced by the prokaryotes. This is an example of: - ANSWER- genetic engineering Isolated RNA molecules are generally less stable than DNA at physiological pH because: - ANSWER-RNA has ribose. Which of the following molecules is able to cross the lipid bilayer? - ANSWER- steroid hormones If the rate constant of a first order reaction that converts substrate S into product P is 0.693 min - 1 then what is the half life of the reaction? - ANSWER-1.000 min The local swimming pool is contaminated with an organism that is causing "swimmers itch." You think you have identified cyanobacteria in your sample. Which features would you expect this organism to LACK? - ANSWER-nucleolus
