遗传学外文习题

1、第一章 遗传的细胞学基础一、 遗传学名词解释染色体 chromosome 姊妹染色单体 sister chromatid 同源染色体 homologous chromosome 染色体组 genome 二价体 bivalent 联会 synapsis 受精 fertilization 双受精 double fertilization胚乳直感 xenia 果实直感metaxenia 无融合生殖apomixis 细胞周期 cell cycle 无性生殖 asexual reproduction 染色体组型karyotype 减数分裂 meiosis 有丝分裂 mitosis3. If an org

2、anism has a diploid number of 16, how many chromatids are visible at the end of mitotic prophase? 32How many chromosomes are moving to each pole during anaphase of mitosis?16Contrast the end results of meiosis with those of mitosis.Define and discuss these terms: (a) synapsis, (b) bivalents, (c) chi

3、asmata, (d) crossing over, (e) chromomeres, (f) sister chromatids, (g) tetrads, (h) dyads, (i) monads.An organism has a diploid number of 16 in a primary oocyte.How many tetrads are present in the first meiotic prophase?8How many dyads are present in the second meiotic prophase?8How many monads migr

4、ate to each pole during the second meiotic anaphase?8Explain why meiosis leads to significant genetic variation while mitosis does not.Describe the role of meiosis in the life cycle of a vascular plant.How are giant polytene chromosomes formed?第二章 遗传物质的分子基础遗传学名词解释遗传密码 genetic code 简并 degeneracy 中心法则

5、 centraldogma 转录 transcription 翻译 translation简答题5. List three main differences between DNA and RNA.9. During translation, what molecule bears the codon? The anticodon?Contras t the positive and negative control systems.Contrast the role of repressor in an inducible system and in a repressible system

6、.第三章 孟德尔遗传一、 遗传学名词解释性状 character 单位性状 unit character 显性性状 dominant character 隐性性状 recessive character 基 因座 locus 等位基因 allele 纯合体 homozygote 杂合体 heterozygote 测交 test cross 完全显性 completedominance 不完全显性 imcomplete dominance 共显性 co-dominance 镶嵌显性 mosaic dominance 基因型genotype 表现型 phenotype 互补作用 complemen

7、tary effect返祖现象 atavism 积力口作用 additive effect 重叠作用 duplicate effect 上位彳用 epistatic effect 显性上位 epistatic dominance隐性上位 epistaticrecessiveness 抑制作用 inhibiting effect 多因效 multigenic effect因多效 pleiotropism二、简答题1、试述分离规律.独立分配规律和连锁交换规律的实质？2、试分析孟德尔成功的原因，对你有何启迪？5. Why was the garden pea a good choice as an

8、experimental organism in Mendels work?50. With regard to the ABO blood types in humans, determine the genotypes of the male parent and female parent: Male parent : Blood type B whose mother was type O Female parent: Blood type A whose father was type BPredict the blood types of the offspring that th

9、is couple may have and the expected proportion of each.1/4 、 1/4、 1/4、1/4A husband and wife have normal vision, although both of their fathers are red-green color-blind, which is inherited as an X-linked recessive condition. What is the probability that their first child will be (a) a normal son?1/4

10、 (b) a normal daughter? 1/2(c) a color-blind son? 1/4(d) a color-blind daughter?0In cats, yellow coat color is determined by the b allele, and black coat color is determined by the B allele. The heterozygous condition results in a coat pattern known as tortoise shell. These genes are X-linked. What

11、kinds of offspring would be expected from a cross of a black male and a tortoise-shell female? What are the chances of getting a tortoise-shell male?0In cattle, coats may be solid white, solid black, or black and white spotted. When tree-breeding solid whites are mated with true-breeding solid black

12、s, the F1 generation consists of all solid white individuals. Following many F1 x F1 matings, the following ratio was observed in the F2 generation: 12/16 solid white 3/16 black and white spotted 1/16 solid blackExplain the mode of inheritance governing coat color and pattern by determining how many

13、 gene pairs are involved and which genotypes yield which phenotypes. Is it possible to isolate a true-breeding strain of black and white spotted cattle? If so, what genotype would they have? If not, explain why not.Three autosomal recessive mutations in Drosophila, all with tan eye color(r 1, r 2, r

14、 3) are independently isolated and subjected to complementation analysis. The results are shown here. r 1 x2-F1: all wild-type eyes, r 1 x3-F 1: all tan eyes. Then r1and r3are alleles, the F 1 phenotype of r 2M3 iswild-type eyesConsider three independently assorting gene pairs, A/a, B/b, and C/c, wh

15、ere each demonstrates typical dominance (A-, B-, C-), and recessiveness (aa, bb, cc). What is the probability of obtaining an offspring that is AABbCc from parents that are AaBbCC and AABbCc ?1/8第四章连锁遗传一、 遗传学名词解释连锁 linkage 干扰 interference 符合系数 coefficient of coincidence连锁群 linkage group 性染色体sex-chro

16、mosome 常染色体 autosome 性连锁 sex linkage sex-linked inheritance交叉遗传 criss-crossinheritance 限性遗传 sex-limited inheritance 从性遗传 sex-influenced inheritance二、简答题Why does more crossing over occur between two distantly linked genes than between two genes located very close together on the same chromosome?Using

17、 two pairs of genes P/ p and Z/z), a test-cross parent ( ppzz) is crossed to an organism of unknown genotype.Analysis of the data indicates that the gametes are produced in the following proportions:PZ, 42,4% Pz, 6.9% pZ, 7.1% pz, 43.6%Draw all possible conclusions about the location of these genes.

18、In Drosophila , females expressing the three X-linked recessive traits, scute (sc) bristles, sable body (s), and vermilion eyes ( v) are crossed with wild-type males. In the F1 generation, all females are wild type, while allmales express all three mutant traits. The cross is carried to the F2 gener

19、ation, and 1000 off spring are counted, with the results shown here. No determination of sex has been made in the F2 data.PhenotypeOffspringscsv314+280+sv150sc+156+s+30sc+v46scs+10+v14Determine the genotypes of the P1 and Fi parents, using proper nomenclature.Determine the sequence of the three gene

20、s and the map distance between them.Are there more or fewer double crossovers than expected? Calculate the coefficient of coincidence. Does this represent positive or negative interference?In a theoretical diploid organism, a female of genotype a b c + + +produces 100 meiotic tetrads. Of these, 68 s

21、how no crossover events. Of the remaining 32, 20 show a crossoverb andbetween a and b, 10 show a crossover between b and c, and 2 show a double crossover between a and between b and c. Of the 400 meiotic products, how many of each of the 8 different genotypes will be produced?(42% 5% 2.5% 0.5 ) ( 16

22、8 20 10 2)Assuming the order a-b-c and the allele arrangement shown above, what is the map distance between these loci?11 6 . Determine the genotypes and proportion of gametes from double crossover, the single crossovers between a and b, single crossovers between b and c, and noncrossover.43. Three

23、genes are in the order d-b-c. The heterozygote db+/+c forms 8 categories of gametes. Identify the noncrossover-gametes , the single crossover gametes, and the double crossover gametes. Which category is likely to have the fewest? Which will have the most?In a cross inNeurospora, involving two allele

24、s B and b, the following tetrad patterns are observed. Calculate thedistance between the locus and the centromere.10Tetrad Patternnumber TOC o 1-5 h z BBbb36bbBB44BbBb4bBbB6BbbB3bBBb7An organism of genotype AaBbCc is test-crossed. The genotypes of the progeny are as follows:20Aa Bb Cc20Aa Bb cc20aa

25、bb Cc20aa bb cc5Aa bb Cc5Aa bb cc5aa Bb Cc5aa Bb ccIf these three genes are all assorting independently of each other, how many genotypic classes would you expectin the progeny of the testcross?8If these three genes are so tightly linked that crossover never occurs, how many genotypic classes would

26、you expect in the progeny of the test cross?2What can you conclude from the actual data?ab linkage 20%A, B, and D are linked, and the sequence is A-B-D, assuming ra-b =16%, r b-d=8%, I=0.5, what are thegenotypes and ratio of the gametes of the heterozygote AbD/aBd？第五章 染色体变异一、 遗传学名词解释缺失 deletion 或 de

27、ficiency 重复 duplication 位置效应 position effect 剂量效应 dosage effect 倒位 inversion 易位 translocation 假显性 pseudo-dominant 染色体组 genome 整倍体 Euploid 一倍体 monoploid 单倍体 haploid 二倍体 diploid 同源多倍体autopolyploid 异源多倍体 双二倍体 Allopolyploid 非整倍体 aneuploid超倍体 hyperploid 亚倍体 hypoploid 缺体 nullisomic 单体 monosomic “ Turner 氏

28、综合症” 三体 trisomic 先 天愚型 Down 氏综合征 Down syndrome1. For a species with a diploid number of 18, indicate how many chromosomes will be present in the somatic nuclei of individuals that are haploid, triploid, tetraploid, trisomic, and monosomic.Define the following pairs of terms, and distinguish between

29、them:aneuploidy/euploidymonosomy/trisomy13 Patau syndrome/Edwards syndrome 18autopolyploidy/allopolyploidyautotetraploid/amphidiploid内 paracentric inversion/pericentric inversion 间Contrast the relative survival times of individuals with Down, Patau, and Edwards syndromes. Speculate as to why such di

30、fferences exist.What evidence suggests that Down syndrome is more often the result of nondisjunction during oogenesis rather than during spermatogenesis?Contrast the fertility of an allotetraploid with an autotriploid and an autotetraploid.A human female with Turner syndrome also expresses the X-lin

31、ked trait hemophilia, as did her father. Which ofher parents underwent nondisjunction during meiosis, giving rise to the gamete responsible for the syndrome?mother produce non-X ootidThe primrose, Primula kewensis, has 36 chromosomes that are similar in appearance to the chromosomes in tworelated sp

32、ecies, Primula fioribunda (2n = 18) and Primula verticillata (2n = 18). How could P kewensis arisefrom these species? How would you describe P kewensis in genetic terms?allotetraploid or amphidiploidIndicate the expected number of Barr bodied in interphase cells of the following individuals:klinefel

33、ter syndrome; turner syndrome; karyotypes 47, XYY; 47, XXX; and 48, XXXX.第六章 细菌和病毒的遗传遗传学名词解释影印培养法原噬菌体 prophage 溶原性细菌 lysogenic bacteria 转化 transformation 感受态 competence 接合 conjugation 性导 sexduction F 因子 fertility factor F 因子 F prime factor 转导 transduction 普遍性转导 generalized transduction 转导体 transduci

34、ng particle 共转导 cotransduction 流产转导局限转导restricted transduction F 菌株 F 菌株 Hfr 菌株 F 菌株 质粒 plasmid 附加体 episome简答题Distinguish between the three modes of recombination in bacteria.Describe the observations that led Zinder and Lederberg to conclude that the prototrophs recovered in their transduction expe

35、riments were not the result of F-mediated conjugation.Define plaque, lysogeny, and prophage. 噬菌斑 溶源性 原噬菌体List the major differences between (a) the F + x F- and the Hfrx F- bacterial crosses, and (b) F +, F-, Hfr, and Fbacteria.4. If a single bacteriophage infects one E. colt cell present on a lawn of bacteria and upon lysis yields 200 viable viruses, how many phages will exist in a single plaque if only three more lyric cycles occur? (200) 4 第七章基因突变一、 遗