Question

What is one difference between mitosis and meiosis?

1.chromatids do not separate at the centromere in anaphase 1
2.crossing over occurs only in the prophase of mitosis
3.centromeres do not exist in anaphase 1
4. chromosomes line up at the equator of the cell

Answer 1

Crossing over is a process unique to meiosis I, occurring during prophase I and contributing to genetic variability, unlike in mitosis where such pairing and exchange of genetic material do not happen.

Step-by-step explanation:

Crossing over is one key difference between mitosis and meiosis, which occurs during prophase I of meiosis but not in mitosis. In mitosis, chromosomes do not pair up to form tetrads and do not exchange genetic material. By contrast, during meiosis I, homologous chromosome pairs come together with a synaptonemal complex, engage in crossing over of genetic material at chiasmata, and align as tetrads on the metaphase plate. This is instrumental in increasing genetic diversity and is essential for sexual reproduction.