Question

Linked genes can get segregated during the _______ stage of meiosis-I.

• A. Diakinesis
• B. pachytene
• C. zygotene
• D. diplotene

Answer 1

The correct option is B pachytene

The genes which are placed closely on the same chromosome are called linked genes. Linked genes have high chances of being carried together by the chromosome as these are close to each other. The prophase of meiosis I is divided into five stages: leptotene, zygotene, pachytene, diplotene, and diakinesis. The Leptotene stage marks the arrangement of chromatin fibres into thin, long strands. During the zygotene stage, the synapsis of homologous chromosomes takes place, along with the formation of synaptonemal complexes. Pachytene marks the recombination of genes and crossing over. Diplotene is marked by the formation of chiasma. Terminalisation of chiasmata occurs in diakinesis.

In the pachytene stage, the process of the exchange of fragments of non-sister chromatids of homologous chromosomes occurs. The process is referred to as crossing over. It is during this process that there is a tendency of the linked genes to get separated provided they are distantly located.