Question

Which of the following factor increases the frequency of crossing over?

• A. Temperature
• B. X-ray
• C. Age
• D. Both A and B

Answer 1

Answer: (D)

Both A and B

There are certain factors which change the rate of crossing over. Temperature changes, shock and radiation exposure can result in a change in the frequency of crossing over. When there is a change in the temperature, there are increased chances of crossing over. Due to the heat supplied, the chromosomes are less stable and this increases the sites of exchange of genetic material.

When the cells are exposed to X-rays, the genetic material gets mutated due to the radiations. This radiation also affects the stability of the chromosomes which increases the chances of crossing over.

Thus, the correct answer is option D.