During meiosis I, the chromosomes start pairing at

Options

(a) Leptotene
(b) Zygotene
(c) Pachytene
(d) Diplotene

Correct Answer:

Zygotene

Explanation:

During zygotene, a substage of Prophase I of meiosis I, chromosomes start pairing together called synapsis. Such paired chromosomes are called as homologous chromosomes. A complex structure i.e., synaptonemal complex is formed by a pair of synapsed homologous chromosomes called a bivalent or a tetrad.