Question

Crossing over occurs between

• A. Sister chromatids
• B. Non-sister chromatids
• C. Homologous chromosomes
• D. Any two chromosomes

Answer 1

The correct option is B Non-sister chromatids

Non-sister chromatids refer to either of the two chromatids of paired homologous chromosomes, that is, the pairing of a paternal chromosome and a maternal chromosome.

Crossing over is the exchange of chromosome segments between non-sister chromatids during the production of gametes. The effect is to shuffle the alleles on parental chromosomes so that the gametes carry combinations of genes different from either parent.

So, the correct option is 'Non-sister chromatids'.