Question

What are the mechanisms driving the completion of meiosis 1 related to?

Answer 1

Meiosis I:

1. Meiosis is a type of cell division in which the parent cell's number of chromosomes is halved, yielding four gamete cells.
2. This technique is required for sexual reproduction to produce egg and sperm cells.
3. During meiosis I, the chromosomes of a diploid cell resegregate, resulting in four haploid daughter cells.
4. During this step of meiosis, genetic diversity is formed.
5. Following fertilization, a rise in cytosolic Ca2+ indicates that meiosis is complete.
6. The metaphase to anaphase transition in eggs stopped at metaphase II is caused by a Ca2+-dependent activation of the anaphase-promoting complex.
7. The mechanisms governing the end of meiosis I are similar to but different from those governing the end of mitosis.
8. Spindle disassembly, like in mitosis, must take place at the conclusion of meiosis I in order for the two sets of sister-chromatid pairs to be segregated on different new spindles in meiosis II.
9. On the other hand, some late mitotic activities in animal cells—such as nuclear reformation and chromosomal decondensation, for instance—are not necessary for the second division's preparation and, in many instances, do not occur or only partially occur.
10. After a single S phase, meiosis consists of two rounds of chromosomal segregation (Anaphases I and II).
11. Homologous chromosomes recombine and connect with bivalents during prophase I.
12. While sister chromatids are divided during meiosis II, homologous chromosomes are split during meiosis I.