Solved CSIR Life sciece cell biology questions Part 1

51. During anaphase II
(a) homologues separate and migrate towards opposite poles.
(b) sister chromatids separate and migrate towards opposite poles.
(c) nuclei reform.
(d) chromosomes line up in a single file.


52. During anaphase I
(a) homologues separate and migrate towards opposite poles.
(b) sister chromatids separate and migrate towards opposite poles.
(c) nuclei reform.
(d) chromosomes line up in a single file.

53. Cytokinesis is the
(a) exchange of homologous regions of nonsister chromatids.
(b) formation of tetrads.
(c) independent assortment of chromosomes.
(d) division of one cell into two

54. Centrioles separate during
(a) cytokinesis.
(b) prophase I and prophase II
(c) metaphase I and metaphase II.
(d) anaphase I and anaphase II.

55. Crossing over occurs during
(a) cytokinesis. (b) metaphase I.
(c) prophase II. (d) prophase I

56. Regions where nonsister chromatids cross are called
(a) inversions. (b) homologues.
(c) tetrads (d) chiasmata.

57. In humans, the haploid number of chromosomes is 23. Independent assortment has
the possibility of producing _____ different gametes.
(a) 232 (b) 8 million
(c) 223 (d) 24

58. Crossing over is
(a) the movement of genetic material from one chromosome to a nonhomologous
chromosome.
(b) independent assortment of chromosomes.
(c) the formation of chiasmata.
(d) the exchange of homologous portions of nonsister chromatids.

59. Variation occurs when chromosomes are shuffled in _____ and fertilization.
(a) mitosis (b) genetic drift
(c) meiosis (d) mutation

60. Heritable variation is required for
(a) meiosis. (b) mitosis.
(c) evolution. (d) asexual reproduction.

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