遗传学课程习题集

《遗传学》习题集

第一章绪论

第二章遗传的细胞学基础

一、遗传学名词解释

原核细胞prokaryotic cell真核细胞eukaryotic cell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 超数染色体supernumerary chromosome 联会复合体synaptonemal complex 反应规范reaction norm 交叉的端化terminalization 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

二、简答题

1. Discuss the concepts of homologous chromosomes, diploidy, and haploidy. What characteristics

are shared between two chromosomes considered to be homologous?

2. Describe the events that characterize each stage of mitosis.

3. If an organism has a diploid number of 16, how many chromatids are visible at the end of mitotic

prophase? How many chromosomes are moving to each pole during anaphase of mitosis?

4. Describe how chromosomes are named on the basis of their centromere placement.

5. What "checkpoints" occur in the cell cycle? What is the role of each?

6. Contrast the end results of meiosis with those of mitosis.

7. Define and discuss these terms: (a) synapsis, (b) bivalents, (c) chiasmata, (d) crossing over, (e)

chromomeres, (f) sister chromatids, (g) tetrads, (h) dyads, (i) monads.

8. An organism has a diploid number of 16 in a primary oocyte.

(a) How many tetrads are present in the first meiotic prophase?

(b) How many dyads are present in the second meiotic prophase?

(c) How many monads migrate to each pole during the second meiotic anaphase?

9. Contrast spermatogenesis and oogenesis. What is the significance of the formation of polar

bodies?

10. Explain why meiosis leads to significant genetic variation while mitosis does not.

11. Describe the role of meiosis in the life cycle of a vascular plant.

12. How are giant polytene chromosomes formed?

13. If a human nucleus is 10μm in diameter, and it must hold as much as 2 m of DNA, which is complexed into nucleosomes that during full extension are 11 nm in diameter, what percentage of the volume of the nucleus is occupied by the genetic material?

14. An organism has a diploid number of 16 in a primary oocyte.

(a) How many tetrads are present in the first meiotic prophase?

(b) How many dyads are present in the second meiotic prophase?

(c) How many monads migrate to each pole during the second meiotic anaphase?

15. Contrast telophase in plant and animal mitosis.

16. Explain why meiosis leads to significant genetic variation while mitosis does not.

17、有丝分裂的遗传学意义

18、减数分裂的遗传学意义

19、有丝分裂和减数分裂的异同

三、判断题（正确理解题中的叙述，你认为对的请在题后划“＋”，错的请划“－”）

1、染色质和染色体都是由同样的物质构成的。（）

2、体细胞和精细胞都含有同样数量的染色体。（）

3、桃子的体细胞染色体数2n=16，其雌配子的8条染色体全部来自母本。（）

4、有丝分裂使亲代细胞和子代细胞的染色体数都相等。（）

5、每种生物都有核仁，但多少不一。（）

6、在细胞减数分裂时，任意两条染色体都可能发生联会。（）

7、染色体和染色质是由不同的物质组成的，且形态结构也不同。（）

8、一个成熟的卵细胞中有36条染色体，其中18条一定来自父本。（）

9、无融合生殖产生的胚，其染色体数均是n。（）

10、在减数分裂过程中，同源染色体的配对发生在偶线期，而同源染色的分离发生第一次分裂后期。（）

11、细胞减数分裂时，第一次分裂是同源染色体分离；第二次分裂是染色单体分离。（）

12、在正常的卵子发生中，50个初级精母细胞将产生200个精子。（）

13、减数分裂既为性状遗传提供了物质基础，也为变异提供了物质基础。（）

四、填空题