Q16Multiple choice
chromosomes and some with 32 chromosomes. What possible reasons could you assign to this difference in chromosome number. Do you think cells with 16 chromosomes could have arisen from cells with 32 chromosomes or vice versa? 6. The following events occur during the various phases of the cell cycle, Name the phase against each of the events.
- a.Disintegration of nuclear membrane _________________________
- b.Appearance of nucleolus _________________________
- c.Division of centromere _________________________
- d.Replication of DNA _________________________ 7. Mitosis results in producing two cells which are similar to each other. What would be the consequence if each of the following irregularities occur during mitosis? a. Nuclear membrane fails to disintegrate b. Duplication of DNA does not occur c. Centromeres do not divide d. Cytokinesis does not occur. CELL CYCLE AND CELL DIVISION 53 8. Both unicellular and multicellular organisms undergo mitosis. What are the differences, if any, observed in the process between the two? 9. Name the pathological condition when uncontrolled cell division occurs. 10. Two key events take place, during S phase in animal cells, DNA replication and duplication of centriole. In which parts of the cell do events occur? 11. Comment on the statement – Meiosis enables the conservation of specific chromosome number of each species even though the process per se, results in reduction of chromosome number. 12. Name a cell that is found arrested in diplotene stage for months and years. Comment in 2-3 lines how it completes cell cycle? 13. How does cytokinesis in plant cells differ from that in animal cells?