课程名称︰普通生物学乙上
课程性质︰必修
课程教师︰朱家莹/王俊能 合授
开课学院：医学院
开课系所︰医学系
考试日期（年月日）︰109/01/06
考试时限（分钟）：110
试题 :
Multiple Choice(69%) 1.5% each. Choose the one alternative that best completes the statement or answers the question
1)A microarray is a tool used in genetic research to determine the mRNAs being produced in a particular tissue, and their relative level of expression. Known genes can therefire be assayed for their expression in different situations. One use of the technology is in cancer diagnosis and treatment. If a known gene functions as a tumor supprssor, predict which of the following pieces of evidence would be most useful in diagnosis of a cancer due to a mutation in this tumor-suppressor gene.
A)The tissue sample responds to treatment with a mitosis-promoting compund.
B)The mRNAs for cyclins and kinases show unusually high levels of expression.
C)The mRNAs for the targeted tumor suppressor sequence are not being produced.
D)The tissue sample shows a high level of gene expression relative to a control(noncancerous) sample.
2)Studies in knockout mice have demonstrated an important role of the FOXP2 transcription factor in the development of vocalizations. Recent sequence may be different, the protein sequence it codes for is identical. Which of the following conclusions might logically be inferred from this information?
A)Human and Neanderthal vocalizations may have been more similar than previously thought.
B)There was a problem with the experiment because different DNA sequences cannot result in the same protein sequence.
C)The differences in DNA sequence support the hypothesis that Neanderthals wereprimitive beings that could only grunt.
D)The experiments in mice demonstrating the function of the FOXP2 gene are not relevant to humans and Neanderthals because they are not primates.
3)A current view of howthe human and chimpanzee can share most of their nucleotide sequences yet exhibit significant phenotypic differences is that many of the most important sequence differences alter _____.
A)structural genes
B)the number of repected sequences
C)environmental factors
D)regulatory sequences
4)Biologists now routinely test for homolgy between genes in different species. If genes are determined to be homologous, how are they related to each other?
A)in function but not structure
B)descent from a common ancestor
C)by chance mutations
D)because of convergent evolution
5)Several of the differnet globin genes are expressed in humans, but at different times in development. Which of the listed mechanisms could allow for this?
A)differential translation of mRNAs
B)differential gene regulation over time
C)exon shuffling
D)pseudogene activation
6)How do transposons and retrotransposons differ in how they move around in a genome?
A)Transposons move by viruses and retrotransposons move by bacteria.
B)Transposons move by viruses and retrotransposons move by plasmids.
C)Transposons move by means of a RNA intermediate and retrotransposons move by means of an DNA intermediate.
D)Transposons move by means of a DNA intermediate and retrotransposons move by means of an RNA intermediate.
7)In humans, the embryonic and fetal forms of hemoglobin have a higher affinity for oxygen than that of adults. Why is this the case?
A)Nonidentical genes produce different versions of globins during development.
B)The attachment of methyl groups to cytosine following birth changes the type of hemoglobin produced.
C)Pseudogenes interfere with gene expression in adults.
D)Histone proteins change shape during embryonic developmet.
8)Why is it more difficult to idenetify eukaryotic genes than prokaryotic genes using genomic techinques?
A)There are introns in eukaryotic genes.
B)The proteins are larger in eukaryotes than in prokaryotes.
C)There are no start codons in eukaryotic genes.
D)The coding portions of genes in eukaryotes are shorter than in prokaryotes.
9)When imbalances occur in the sex ratio of sexual species that have two sexes (that is, other than a 50-50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents thean do the offspring of the majority sex. This is most clearly an example of __________.
A)frequency-dependent selection
B)stabilizing selection
C)sexual selection
D)balancing selection
10)Arrange the following in order from most general to most specific.
1.natural selection
2.microevolution
3.intrasexual selection
4.evolution
5.sexual selection
A)4,2,1,5,3
B)4,2,1,3,5
C)4,1,2,3,5
D)1,4,2,5,3
11)The restriction enzymes of bacteria protect the bacteriafrom successful attack by bacteriaophages, whose genomes can be degraded by the restriction enzymes. The bacterial genomes are not vulnerable to these restriction enzymes because strains of resistant bacteriophages become more prevalent, this in turn selects for bacteria whose genomes are not methylated and whose restriction enzymes instead degrade methylated DNA. Overthe course of evolutionary time, what should occur?
A)Nonmethylated DNA should become fixed in the gene pools of bacteriophages.
B)Methylated and nonmethylated strains should be maintained among both bacteria and bacteriophages, with ratios that over time.
C)Methylated DNA should become fixed in the gene pools of bacteriophages.
D)Methylated DNA should become fixed in the gene pools of bacterial species.
12)You are maintaining a small population of fruit flies in the laboratory by transferring the flies to a new culture bottle after each generation. After several generations, you notice that the viability of the flieshas decreased greatly. Recognizing that small population size is likely to be linked to decreased viability, the best way to reverse this trend is to ____________.
A)reduce the number of flies that you transfer at each generation
B)change the temperature at which you rear the flies
C)cross your flies with flies from another lab
D)transfer only the largest flies
13)The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid-1700s. They do not marry with members outside their own immediate community. Today, the Dunkers are genetically unique and differ in gene frequencies, at many loci, from all other populations including those in their original homeland. Which of the following mechanisms likely explains the genetic uniqueness of this population?
A)population bottleneck and Hardy-Weinberg equilibirum
B)founder effect and genetic drift
C)heterozygote advanttage and stabilizing selection
D)mutation and natural selection
14)A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 25% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. What is the estimated frequency of allele A in the gene pool?
A)0.125
B)0.75
C)0.25
D)0.50
15)Use the following ingormation to answer the question below. Researchers studying a small milkweed population note that some plants produce a toxin and other plants do not. They identify the gene responsible for toxin production. The dominant allele(T) codes for an enzyme that makes the toxin, and the recessive allele(t) codes for a nonfunctional enzyme that cannot produce the toxin. Heterozygotes produce an intermediate amount of toxin. The genotypes of all individuals in the population are determined
(see chart) and used to determined in the actual all frequencies in the population.