In oocyte of some vertebrates, the stage of meiosis I that can last for months or years would be:
When a cell stops growing, say due to shortage of nutrients, this will occur in which phase of the cell cycle?
At what phase of meiosis are homologous chromosomes separated ?
1. Prophase l
2. Prophase ll
3. Anaphase l
4. Anaphase ll
Anaphase promoting complex (APC) is a protein degradation machinery necessary for proper mitosis of animal cells. If APC is defective in a human cell, which of the following is expected to occur?
(a) Chromosomes will not condense
(b) Chromosomes will be fragmented
(c) Chomosomes will not segregate
(d) Recombinantion of chromosome arms will occur
DNA replication in bacteria occurs
(a) during S-phase
(b) within nucleolus
(c) prior to fission
(d) just before transcription
Which of the following options gives the correct sequences of events during mitosis?
During cell growth, DNA synthesis takes place in
(a) S-phase (b) -phase
(c) -phase (d) M-phase
When cell has stalled DNA replication fork, which checkpoint should be predominantly activated?
(d) Both G2/M and M
Match the stage of meiosis in column I to their characteristic features in column II and select the correct option using the codes given below
Column l Column ll
A. pachyetne 1. pairing of homologous chromosomes
B. Metaphase-l 2. Terminalisation of chaismata
C. Diakinesis 3. Crossing-over takes place
D. Zygotene 4. Chromosomes align at equatorial plate
The correct option:
A B C D
(a) 3 4 2 1
(b) 1 4 2 3
(c) 2 4 3 1
(d) 4 3 2 1
A cell at telophase stage is observed by a student in a plant brought from the field. He tells his teacher that his cell is not like other cells at telophase stage. There is no formation of cell plate and thus the cell is containing more number of chromosomes as compared to other dividing cells. This would result in
(b) somaclonal variation