Question

Homologous chromosomes in zygotene pair due to attraction and synaptonemal complex formation. Which of the following is true for diplotene phase?

(a) The chromosomes still attract although synaptonemal complex degenerates

(b) The synaptonemal complex persistes but chromosomes develop opposite charges

(c) The chromosomes repel and completely separate

(d) The synaptonemal complex breaks down

The question was asked in an online interview.

Origin of the question is Meiosis Prophase 1 : Diplotene and Diakinesis topic in section Chromosomal Changes During Meiosis of Cytogenetics

Answer 1

Right answer is (d) The synaptonemal complex breaks down

The explanation: In the diplotene stage the chromosomes repel each other and synaptonemal complex breaks down. Repulsion can’t be due to opposite charge but like charge, also they don’t separate completely but are joined at the crossing over sites which gradually terminalize.