Tiêu đề CELL CYCLE & CELL DIVISION.pdf ✅

Cell Cycle and Cell Division  Digital www.allendigital.in [ 223 ] INTRODUCTION TO MODIFICATIONS OF MITOSIS 1. During G2 - phase a diploid cell contains the amount of DNA equal to a :- (1) Diploid cell (2) Tetraploid cell (3) Haploid cell (4) Hexaploid cell 2. In which order, cytokinesis occurs in plants: (1) Centripetal (2) Centrifugal (3) Oblique (4) Equatorial 3. Nuclear envelope reappears at :- (1) Metaphase (2) Prophase (3) Anaphase (4) Telophase 4. Which does not occurs in prophase ? (1) Decondensation of chromatin (2) Condensation of chromatin (3) Appearance of chromosome (4) Disappearance of nuclear membrane and nucleolus 5. In which stage of cell division, number of chromosomes can be best counted? (1) Prophase (2) Metaphase (3) Telophase (4) Interphase 6. How many chromosomes shall be present in a diploid cell at mitotic anaphase if ovum of same species has ten chromosomes? (1) 10 (Ten) (2) 20 (Twenty) (3) 30 (Thirty) (4) 40 (Forty) 7. In which stage of mitosis, the chromosomes are composed of two chromatids ? (1) Prophase & metaphase (2) Anaphase and telophase (3) Prophase and telophase (4) Metaphase and anaphase 8. Gap between division phase and start of DNA-replication is called :- (1) G1 - phase (2) G2 - phase (3) M - phase (4) Interkinesis 9. During cell division, spindle fibres attach to which part of chromosome ? (1) Primary constriction (2) Secondary constriction (3) Telomere (4) Satellite 10. During which stage a diploid cell becomes tetraploid in mitosis? (1) G2 (2) Prophase (3) Metaphase (4) Anaphase 11. Division of centromere occurs in:- (1) Prophase (2) Metaphase (3) Anaphase (4) Telophase 12. What happens in synthesis phase during cell cycle? (1) DNA replication (2) Chromosome number becomes double (3) Formation of two nuclei (4) Synthesis of tubulin proteins 13. Reappearance of nucleolus along with thinning & elongation in chromosomes are diagnostic characters for the :- (1) Anaphase (2) Metaphase (3) Interphase (4) Telophase 14. Condensation of chromosomes and appearance of astral rays occur during :- (1) Prophase (2) Metaphase (3) Anaphase (4) Telophase 15. Chromosomal morphology (Structure) is best observed at :- (1) Prophase (2) Metaphase (3) Interphase (4) Anaphase 16. M–phase of cell cycle consist of :– (1) G1, S and G2 phase (2) Prophase, Metaphase, Anaphase, Telophase (3) Interphase, Prophase, Metaphase, Anaphase, Telophase (4) Only prophase Exercise - I
NEET : Biology [ 224 ] www.allendigital.in  Digital 17. If the cell is diploid in G1 than after the S phase cell remain/become :- (1) n (2) 4n (3) 8n (4) 2n 18. Nuclear membrane disappears in :– (1) Late prophase (2) Early prophase (3) Metaphase (4) Telophase 19. Pre - DNA synthesis phase is:- (1) G1 - phase (2) G2 - phase (3) S-phase (4) Prophase 20. How many steps of division will occur in an isolated tip cell to form 128 cells ? (1) 128 (2) 127 (3) 32 (4) 7 21. The number of chromatids in a chromosome at G2 state of cell cycle will be:- (1) One (2) Two (3) Four (4) Eight 22. Many cells function properly and divide mitotically even though they do not have :- (1) Plasma membrane (2) Cytoskeleton (3) Mitochondria (4) Plastids 23. Centromere is required for – (1) Movement of chromosomes towards poles (2) Cytoplasmic cleavage (3) Crossing over (4) Transcription 24. At which stage of the cell cycle are histone proteins synthesized in a eukaryotic cell ? (1) During telophase (2) During S–phase (3) During G2–phase (4) During entire prophase 25. Prophase which follows the S and G2 phases of interphase, is the first stage of :- (1) Meiosis-II (2) Karyokinesis (3) Interphase (4) G1 phase 26. The two asters together with spindle fibres form:- (1) Mitotic apparatus (2) Centromere (3) Astral fibres (4) Centrosome 27. In prophase centrosome, which had undergone duplication during interphase, begins to move towards : (1) Same pole of the cell (2) Opposite poles of the cell (3) One towards centre while another towards pole (4) Both towards centre MEIOSIS, SIGNIFICANCE OF MEIOSIS, DIFFERENCES BETWEEN MITOSIS AND MEIOSIS 28. Which of the following not occurs in Anaphase–I but occurs in Anaphase–II :– (1) Condensation of chromosomes (2) Poleward movement of chromosomes (3) Shortening of spindle fibres (4) Splitting of centromere 29. Crossing over takes place in :- (1) Zygotene (2) Pachytene (3) Diplotene (4) Diakinesis 30. Which of the two events maintain the constant number of chromosomes across generations? (1) Mitosis and Meiosis (2) Meiosis and fertilisation (3) Fertilisation and mitosis (4) Only meiosis 31. Match the column–I with column–II and select the correct answer :- Column–I Column–II (A) Pachytene (i) Bouquet stage (B) Zygotene (ii) Chiasmata visible (C) Diplotene (iii) Terminalisation (D)Leptotene (iv) Gene exchange (E) Diakinesis (v) Synapsis Options :- (1) A–i, B–ii, C–iii, D–iv, E–v (2) A–iv, B–v, C–ii, D–i, E–iii (3) A–iii, B–iv, C–v, D–ii, E–i (4) A–ii, B–iii, C–iv, D–i, E–v 32. Which part of plant is suitable for the study of meiosis? (1) Root apex (2) Ovary (3) Anther (4) Shoot apex
Cell Cycle and Cell Division  Digital www.allendigital.in [ 225 ] 33. Slipping of chiasmata towards the ends of bivalent is called :- (1) Terminalisation (2) Diakinesis (3) Interkinesis (4) Congression 34. "Bouquet-stage" occur in which sub stages of prophase-I ? (1) Leptotene (2) Zygotene (3) Pachytene (4) Diplotene 35. At anaphase - II of meiosis each chromosome contains:- (1) 4 chromatids (2) 3 chromatids (3) 2 chromatids (4) 1 chromatid 36. In Anaphase – I each chromosome composed of:- (1) One chromatid (2) Two chromatids (3) Four chromatids (4) Many chromatids 37. In meiosis, division of centromere occurs during:- (1) Interphase (2) Anaphase - I (3) Anaphase - II (4) Metaphase - I 38. In meiosis, nuclear membrane and nucleolus disappear during :- (1) Zygotene (2) Pachytene (3) Diakinesis (4) Metaphase - I 39. Separation of homologous chromosomes during anaphase-I is called :- (1) Synapsis (2) Disjunction (3) Nondisjunction (4) Crossing over 40. Diakinesis represents :- (1) transition to prophase (2) transition to metaphase (3) transition to anaphase (4) transition to telophase 41. Synaptonemal complex is characteristic of :- (1) Mitotic chromosomes (2) Leptotene chromosomes (3) Paired meiotic chromosomes (4) Metaphase 42. Each chromosome composed of one chromatid in:- (1) Anaphase – I (2) Anaphase – II (3) Metaphase – I (4) Metaphase – II 43. If the number of bivalents are 8 in metaphase–I, what shall be the number of chromosomes in daughter cells after meiosis–I and meiosis–II respectively:- (1) 8 and 4 (2) 4 and 4 (3) 8 and 8 (4) 16 and 8 44. Which of the following not occurs in anaphase-I? (1) Segregation of homologous chromosomes (2) Shortening in spindle fibres (3) Poleward movement of chromosomes (4) Division of centromere 45. In meiosis :- (1) Division of nucleus twice but replication of DNA only once (2) Division of nucleus twice and replication of DNA twice (3) Division of nucleus once and replication of DNA is also once (4) Division of nucleus once and DNA replication is twice 46. After meiosis–I :- (1) the two chromatids of a chromosome are genetically similar (2) the two chromatids of a chromosome are genetically different (3) There occurs only one chromatid in each chromosome (4) Four similar daughter cells are formed 47. The correct sequence of prophase–I of meiosis is :– (1) Leptotene, pachytene, zygotene, diplotene, diakinesis (2) Leptotene, diplotene, pachytene, zygotene, diakinesis (3) Leptotene, zygotene, pachytene, diplotene, diakinesis (4) Leptotene, zygotene, diakinesis, diplotene, pachytene
NEET : Biology [ 226 ] www.allendigital.in  Digital 48. Which of the following is called heterotypic division ? (1) Meiosis–I (2) Meiosis–II (3) Mitosis (4) Amitosis 49. DNA replication occurs before :– (1) Mitosis and meiosis–I (2) Mitosis, meiosis–I and meiosis–II (3) Meiosis-I only (4) Mitosis only 50. Thick–thread stage is :– (1) Leptotene (2) Zygotene (3) Pachytene (4) Diplotene 51. Crossing over that results in genetic recombination in higher organisms occurs between – (1) Non-sister chromatids of a bivalent (2) Two daughter nuclei (3) Two different bivalents (4) Sister chromatids of a bivalent 52. When synapsis is complete all along the chromosome, the cell is said to have entered a stage called :- (1) Zygotene (2) Pachytene (3) Diplotene (4) Diakinesis 53. If in a diploid plant cell the 'n' value is 16 then what is possible in metaphase - I of meiosis ? (1) 32 Bivalents (2) 64 Bivalents (3) 16 Bivalents (4) 8 Bivalents 54. Which one of the following statements is incorrect for interkinesis ? (1) It is the stage between the two subphases (I & II) of a meiotic division (2) There is no replication of DNA (3) DNA replicate but chromosome number remains same (4) It is generally short lived. 55. At anaphase-II, sister chromatids move towards opposite poles of the cell by : (1) Contraction in spindle fibre attached to kinetochores (2) Shortening of microtubules attached to kinetochores (3) Lengthening of microtubules attached to kinetochores (4) Relaxation in spindle fibre attached to kinetochores EXERCISE-I (Conceptual Questions) ANSWER KEY Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Answer 2 2 4 1 2 4 1 1 1 4 3 1 4 1 2 Question 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Answer 2 4 1 1 4 2 4 1 2 2 1 2 4 2 2 Question 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 Answer 2 3 1 1 4 2 3 3 2 2 3 2 3 4 1 Question 46 47 48 49 50 51 52 53 54 55 Answer 2 3 1 1 3 1 2 3 3 2