Question

Genetic maps of chromosomes are based on the frequency of

• A. Non-disjunction
• B. Translocation
• C. Dominance
• D. Genetic recombination
• E. Chromosomal aberration

Answer 1

Answer: (D)

Genetic recombination

• Genetic recombination or crossing over is the mutual exchange of the corresponding parts of the adjacent paternal and maternal chromatids of the pachytene of meiosis, producing new combinations of genes.
• The chromatids resulting from the interchange of segments are known as the cross over recombinants and the chromatids that remain intact are called as non-cross over paternal chromatids.
• The frequency of crossovers between two genes depends on the distance between them, as crossovers between two genes that are close together are not very common which is why genetic maps are based on recombination frequency.
  

So, the correct answer is 'Genetic recombination'.