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