CSIR Model questions: Cell Cycle

1. DNA replication occurs in
a) S phase
b) G phase
c) G2 phase
d) M phase
2. The pairing of homologous chromosomes
a) Tetrads
b) Crossing over
c) Synapsis
d) Terminalisation
3. Which aspect of mitosis is affected by colchicine in inducing polyploidy?
a) DNA duplication
b) Spindle formation
c) Cell plate formation
d) Chromosome doubling
4. Pairing of homologous chromosomes can be seen during
a) Zygotene
b) leptotene
c) Diplotene
d) Pachytene
5. The cell cycle of a germinal cell has
a) two successive mitotic divisions
b) two successive reduction divisions
c) very short prophase in first division
d) one reduction division followed by one mitotic division
6. During cell division, sometimes there will be failure of separation of sister chromatids. This event is called
a) interference
b) coincidence
c) fusion
d) Non disjunction
7. In the cell cycle DNA synthesis takes place during
a) G1 phase
b) G2 phase
c) S phase
d) Prophase
8. During metaphase mitosis chromosomes
a) undergo coiling
b) Move towards the poles
c) Line up at the equator
d) Break and disintegrate
9. A cell divides every one minute. At this rate of division it can fill a 100 ml of beaker in one hour. How much time does it take to fill a 50 ml beaker?
a) 30 minutes
b) 60 minutes
c) 59 minutes
d) one minute
10. In how many cells the meiotic division has taken place, if the total number of spermatids produced are 32?
a) 16
b) 8
c) 32
d) 4
11. Zygotic meiosis occurs in
a) Pteris
b) Marchantia
c) Puccinia
d) Chalmydomonas
12. Daughter cells are formed as a result of meiosis are not similar to that of parent cell because
a) Meiosis is completed in two stages
b) Prophase is longest phase
c) Nucleus size increases in daughter cells
d) Crossing over takes place and chromosome number is halved
13. During meiosis chiasmata are observed at
a) Pachytene
b) Diplotene
c) Leptotene
d) Diakinesis
14. Number of mitotic divisions required to produce 128 cells from a single cell is
a) 7
b) 8
c) 16
d) 32
15. During which stage of prophase I the crossing over takes place?
a) Pachytene
b) Leptotene
c) Zygotene
d) Diplotene

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