Microtubules from opposite poles of the spindle attach to the pairs of homologous chromosomes during
(1) Pachytene
(2) Metaphase – I
(3) Metaphase – II
(4) Early prophase
Exchange of genetic material between two homologous chromosomes occurs in
(1) Leptotene
(2) Diakinesis
(3) Pachytene
(4) Diplotene
How many meiotic divisions are required to produce 50 wheat grains?
(1) 100
(2) 200
(3) 25
(4) 63
A typical eukaryotic cell cycle is illustrated by human cells in culture. These cells divide once in approximately every
1. 24 hours
2. 90 minutes
3. 20 minutes
4. 9 hours
Choose incorrect statement with respect to cell cycle
(1) Duration of cell cycle can vary from organism to organism
(2) Duration of cell cycle is uniform in different cell types of an organism
(3) Events of cell cycle are under genetic control
(4) It is divided into two basic phases
Choose the correct sequence with respect to different phases of cell cycle
(1) G1 S, G2, M
(2) G1, G2, S, M
(3) M, G2, G1, S
(4) S, M, G2, G1
Human nerve cells do not divide after birth and they remain throughout their life in which phase of cell cycle?
(1) M-phase
(2) G1 phase
(3) G0 phase
(4) Invisible phase
Various phases of cell cycle are controlled by
(1) Cyclin proteins
(2) Cyclin dependent protein kinases
(3) Phosphorylation of cyclin dependent protein kinases
(4) More than one option is correct
Amount of DNA and Number of chromosomes in G2 phase of cell cycle would be
(1) Double and equal to that of in G1 phase respectively
(2) Half and equal to that of in G1 phase respectively
(3) Equal and half to that of in G1 phase respectively
(4) Double and double to that of in G1 phase respectively
Exchange of genetic material between non-sister chromatids of homologous chromosomes in pachytene stage is facilitated by
(1) Dynein
(2) Recombinase
(3) chiasmata
(4) Calmodulin