Question

For the preparation of genetic maps, the recombination frequencies between genes are additive over short distances but not over long distances due to

• A. Multiple cross overs
• B. Lethal mutation
• C. Epistasis
• D. Synaptonemal complex

Answer 1

Answer: (A)

Multiple cross overs

Unless genes are very close together, more than one crossover event can occur in a single meiotic division. Multiple crossovers can make mapping inaccurate if genes are far apart on the same chromosome.