Question

what is a key difference between meiosis and mitosis? synthesis of dna occurs. crossing over only occurs in meiosis. all of these are correct. dna divides twice in mitosis and once in meiosis.

Explanation:

DNA synthesis occurs in both mitosis and meiosis. Crossing - over is a unique event to meiosis where genetic material is exchanged between homologous chromosomes. In mitosis, DNA divides once to produce two genetically identical daughter cells, while in meiosis, DNA divides twice to produce four genetically diverse daughter cells.

Answer:

B. Crossing over only occurs in meiosis.