How do meiosis and fertilization affect ploidy levels?
Meiosis is where a diploid cell gives rise to haploid cells, and fertilization is where two haploid cells (gametes) fuse to form a diploid zygote.
Does meiosis increase ploidy?
If we now apply these facts to the process of meiosis, we can see how ploidy in terms of genetic content and chromosome number differs as meiosis occurs. … Thus, we have reduced the ploidy in terms of genetic content to 1n (haploid genetically), since for each gene locus, only one of the two possible alleles is present.
How do meiosis and fertilization affect ploidy levels chegg?
During fertilization, the haploid sperm (n) and egg (n) fuse, producing a diploid zygote (2n). … Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II.
How does meiosis maintain the ploidy level between generations?
Meiosis produces 4 haploid cells. Mitosis produces 2 diploid cells. The old name for meiosis was reduction/ division. Meiosis I reduces the ploidy level from 2n to n (reduction) while Meiosis II divides the remaining set of chromosomes in a mitosis-like process (division).
Why is there a reduction of ploidy after meiosis I?
The parent cell contained two copies of each chromosome (diploid), while the daughter cells contain only one copy of each chromosome (haploid). This results in the reduction of ploidy after meiosis I. … Since both parent and daughter cells are diploid, there is no reduction of ploidy.
What is the ploidy at the end of meiosis 1?
The ploidy of the DNA at the end of meiosis I each of the two daughters are haploid. At the end of meiosis II, each of the 4 daughters are also haploid.
What is the main cause of polyploidy?
Polyploids arise when a rare mitotic or meiotic catastrophe, such as nondisjunction, causes the formation of gametes that have a complete set of duplicate chromosomes. … When a diploid gamete fuses with a haploid gamete, a triploid zygote forms, although these triploids are generally unstable and can often be sterile.