A) organisation of the spindle
B) synapsis of homologous chromosome
C) nucleo-cytoplasmic exchange of material
D) anaphasic separation of daughter chromosome
Correct Answer: C
Solution :
The nuclear envelope in all eukaryotic forms is perforated by nuclear pores. The ions, nucleotides and structural, catalytic and regulatory proteins are, imported from cytosol, and the mRNA, tRNA, rRNA are exported form nucleus by these pores. The microtubules cause the organization of spindle. The spindle contain three main type of fibres (i) Polar fibres (ii) Kinetochore fibres (iii) Astral fibres (in animal). During zygotene stage of meiosis, the pairing of homologous chromosomes takes place and called synapsis. It is caused by a protein-containing framework called synaptonemal complex. The synchronous splitting of anaphasic chromosome into chromatid is caused by an increase in cytosolic Ca2+ and the movement of chromatid towards pole is due to shortening of kintochore microtubule or elongation of polar micro-tubules.
You need to login to perform this action.
You will be redirected in
3 sec
