Final answer:
Meiosis is a process of cell division in diploid organisms that produces haploid gametes necessary for sexual reproduction, featuring two divisions that result in genetic variation among offspring.
Step-by-step explanation:
Meiosis
is a cellular process that produces
haploid gametes
in
diploid organisms
, such as most animals and some algae, which are essential for sexual reproduction. The process includes two main divisions:
Meiosis I
and
Meiosis II
. In Meiosis I, homologous chromosomes separate, and in Meiosis II, similar to mitosis, sister chromatids separate.
Crossing over
occurs during prophase I of Meiosis I, resulting in new combinations of genes, which is a crucial source of genetic variation. Sexual reproduction combines the unique gametes formed during meiosis to result in genetically diverse offspring.
Crossing over
is not an exchange between sister chromatids, but rather between homologous chromosomes, which counteracts the false statement that crossing-over is the exchange of genetic material between sister chromatids.