Question

The following questions refer to the essential steps in meiosis described below.

1. formation of 2 new nuclei, each with n numberchromosomes present

2. alignment of dyadsat the metaphase plate

3. separationof sister chromatids

4. separationof the homologs; no uncoupling of centromeres

5. synapsis; tetrad “chromosomes” moving to the middle of the cell in pairs

49.__  From the descriptions above, which of the following is the orderthat most logically illustrates a sequence of meiosis?

A) 5, 4, 2, 3, 1      B) 5, 4, 1, 2, 3         C) 5, 3, 2, 4, 1           D) 4, 5, 2, 1, 3    E) 5, 2, 4, 3, 1

50.__ Which of the steps take place in only meiosisandnot in mitosis?

A) 1,2, and 3

B) 1,2,4, and 5

C) 1,4, and 5

D) 2 and 3 only

E) 2,3, and 5

55.__ During which portions of the cell cycle are “chromosomes” composed of two chromatids (dyads)?

A) during interphase through anaphase

B) during G₁of interphase through metaphase

C) during metaphase through telophase

D) during anaphase through telophase

E) during G₂of interphase through metaphase

56.___ Which of these statements is false?

A) In humans, each of the 22 maternal autosomes has a homologous paternal chromosome.

B) In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY).

C) Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote.

D) At sexual maturity, ovaries and testes produce diploid gametes by meiosis.

E) Sexual life cycles differ with respect to the relative timing of meiosis and fertilization.

59.__ All of the following are functions of meiosis in protists (algae) except:

A) reduction of chromosome number by half.

B) independent assortment of chromosomes.

C) production of spore cells.

D) production of gamete cells.

E) crossing over and recombination of homologous chromosomes.

60.___ How do the 4 daughter cells at the completion of meiosis compare with cells that have replicated DNA and are just about to begin G₂ of interphase?

A) They have twice the amount of cytoplasm and half the amount of DNA.

B) They have half the number of chromosomes and half the amount of DNA.

C) They have the same number of chromosomes and half the amount of DNA.

D) They have half the number of chromosomes and one-fourth the amount of DNA.

E) They have half the amount of cytoplasm and twice the amount of DNA.

Answer 1

49. Correct answer:- (E) 5,2,4,3,,1

Explanation:- correct steps in meiosis are -

synapsis; tetrad “chromosomes” moving to the middle of the cell in pairs

alignment of dyadsat the metaphase plate

separationof the homologs; no uncoupling of centromeres

separationof sister chromatids1. formation of 2 new nuclei, each with n numberchromosomes present

50. Correct answer:- (E) 2,3,5

Explanation:- meiosis contain-

2. alignment of dyadsat the metaphase plate

3. separationof sister chromatids

5. synapsis; tetrad “chromosomes” moving to the middle of the cell in pairs.

55. Correct answer:- (B) during G1of interphase through metaphase.

56. Correct answer:- (D)  At sexual maturity, ovaries and testes produce diploid gametes by meiosis.

Explanation:- gamets produced in germ cell are always haploid.

59. Correct answer:- (C) production of spore cells.

Explanation:- spores are produced by mitosis.

60. Correct answer:- (B) They have half the number of chromosomes and half the amount of DNA.

-