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#	Question	Answer
1	What are the two important characteristics of cells mentioned in the chapter?	Growth and reproduction.
2	During which stage of the cell cycle does DNA synthesis occur?	During one specific stage of the cell cycle.
3	Approximately how long does a human cell take to complete one cell cycle?	About 24 hours.
4	What is cytokinesis?	Division of the cytoplasm.
5	What happens to the DNA content during S phase?	It doubles from 2C to 4C.
6	What is the quiescent stage of the cell cycle called?	G0 stage.
7	Can plants show mitotic division in both haploid and diploid cells?	Yes.
8	What happens to chromatin during prophase?	It condenses and becomes untangled.
9	What is the condition of cells in G0 stage?	They remain metabolically active but no longer proliferate unless required.
10	Which phase is considered the most dramatic period of the cell cycle?	M Phase.
11	What is the condition of newly formed DNA molecules before prophase?	They are not distinct but intertwined.
12	What forms the mitotic apparatus?	Two asters together with spindle fibres.
13	What is a metaphase chromosome made up of?	Two sister chromatids held together by the centromere.
14	How are sister chromatids attached during metaphase?	Each chromatid is connected by its kinetochore to spindle fibres from opposite poles.
15	Which part of the chromosome leads during movement in anaphase?	The centromere.
16	Can individual chromosomes be seen clearly during telophase?	No, they cannot be seen as discrete elements.
17	What process does mitosis accomplish before cytokinesis?	Segregation of duplicated chromosomes into daughter nuclei (karyokinesis).
18	What is the precursor formed during cytokinesis in plant cells?	Cell plate.
19	To which cells is mitosis usually restricted?	Diploid cells.
20	What is one important contribution of mitosis?	Cell repair.
21	What restores the diploid phase in sexually reproducing organisms?	Fertilisation.
22	How many haploid cells are formed at the end of meiosis II?	Four haploid cells.
23	Name the five stages of prophase I.	Leptotene, Zygotene, Pachytene, Diplotene, and Diakinesis.
24	What are homologous chromosomes?	Paired chromosomes during synapsis.
25	What becomes distinct during pachytene?	The four chromatids of each bivalent chromosome.
26	What is the result of crossing over?	Recombination of genetic material.
27	What marks diakinesis?	Terminalisation of chiasmata.
28	What happens during metaphase I?	Bivalent chromosomes align on the equatorial plate.
29	What follows telophase I?	Cytokinesis.
30	When is meiosis II initiated?	Immediately after cytokinesis.
31	To what do spindle microtubules attach in metaphase II?	Kinetochores of sister chromatids.
32	What happens to chromosomes during telophase II?	They get enclosed by a nuclear envelope.
33	What is another important significance of meiosis?	It increases genetic variability in populations.
34	Does cell division stop after formation of a mature organism?	No, it continues throughout life.
35	Into which phases is interphase subdivided?	G1, S, and G2 phases.
36	Name the four stages of mitosis.	Prophase, Metaphase, Anaphase, and Telophase.
37	What characterises metaphase?	Alignment of chromosomes at the equatorial plate.
38	Why is mitosis called equational division?	Because chromosome number is conserved in daughter cells.
39	What happens during meiosis I?	Homologous chromosomes pair to form bivalents and undergo crossing over.
40	What reappears during telophase I?	Nuclear membrane and nucleolus.
41	What is cytokinesis?	Division of the cytoplasm into two daughter cells.
42	During which stage are chromosomes moved to the spindle equator?	Metaphase.
43	What is a bivalent?	A pair of synapsed homologous chromosomes.
44	What is the main difference between anaphase of mitosis and anaphase I of meiosis?	In mitosis sister chromatids separate, while in meiosis I homologous chromosomes separate.
45	What happens to DNA content (C) during S phase?	It doubles.