Question

1. Give a schematic representation of oogenesis in human females.
2. Mention the number of chromosomes at each stage. Correlate the life phases of the individual with the stages of the process.

Answer 1

1. 
   
2. Chromosome number and life phases:
   

   Stage	Chromosome Number	Life Phase Correlation
   Oogonium	2n (46)	Fetal development
   Primary oocyte	2n (46)	Fetal development is arrested at prophase I until puberty.
   Secondary oocyte	n (23)	From puberty until menopause, released monthly during ovulation, arrested at metaphase II.
   Ovum	n (23)	After fertilisation, completes meiosis II
   Polar bodies	n (23)	Degenerate and play no further role