Question

what is a key difference between meiosis and mitosis?

• crossing over only occurs in mitosis.
• synthesis of dna occurs.
• there is a difference in the number of times dna is divided.
• all of these are correct.

Explanation:

• Crossing over: Occurs in meiosis (prophase I) not mitosis. So the first option is wrong.
• DNA synthesis: Happens in the interphase before both mitosis and meiosis (S - phase). So the second option is wrong.
• Number of DNA divisions: Mitosis has one DNA division (one - round of cell division), meiosis has two DNA divisions (two - round of cell divisions).

Answer:

C. There is a difference in the number of times DNA is divided.