Question

Name a cell that is found arrested in the diplotene stage for months and years. Comment in 2-3 lines how it completes the cell cycle.

Answer 1

Cells arrested at diplotene stage

Cells like oocytes of some vertebrates (for example, oocyte of mammalian females) are generally found arrested in the diplotene stage for years until the female reaches puberty.


Completion of cell cycle

• The oocytes arrested in the diplotene stage complete their cell cycle after stimulation with the female gonadotropin, predominantly LH surge.
• The hormone activates various factors to drive cytoplasmic and nuclear changes which help the oocyte to resume meiosis and progresses to metaphase II.
• The oocyte again gets arrested at metaphase II which represents the appropriate stage to be fertilised.
• On the occurrence of fertilisation, meiosis II is completed. This releases the haploid ovum (ootid).