Rachael is observing a few slides taken from a female orangutan. She observes an ovarian slide where all the cells show chromosome tetrads in synapses. Which stage of meiosis has Rachael observed?

1 Answer
Dec 5, 2017

Rachael has seen the cells in prophase 1 of meiosis . Specifically tetrads are seen in PACHYTENE substage of prophase 1. (Tetrads show chiasmata in next stage of prophase 1 i.e. in diplotene.)

Explanation:

Please note two things (regarding the statements in question):

  • in a tissue section not all cells will undergo meiosis, only primary oocytes will undergo meiosis 1.

AND

  • first meiotic division starts in fetal life and it remains arrested after childhood in hominids (apes and human).

https://embryology.med.unsw.edu.au/embryology/images/thumb/3/3c/Infant_ovary.jpg/500px-Infant_ovary.jpg