Admin Table of Contents
What overall impact does crossing over have on the genetic diversity of a population?
However, crossing over exchanges genetic material between homologous chromosomes and results in new combinations of alleles. New allele combinations end up in gametes / are different from parental allele combinations therefore increase genetic variation.
What happens when an individual has an odd number of chromosome sets eg Triploidy )?
Thus, polyploids with an odd number of chromosomes (e.g. triploids, 2n=3x) tend to be sterile, even if they are otherwise healthy. The mechanism of meiosis in stable polyploids is essentially the same as in diploids: during metaphase I, homologous chromosomes pair with each other.
What would happen if the sister chromatids failed to separate?
If sister chromatids fail to separate during meiosis II, the result is one gamete that lacks that chromosome, two normal gametes with one copy of the chromosome, and one gamete with two copies of the chromosome.
Why is crossing over advantageous in a population?
A benefit of crossing over is that it maintains genetic diversity within a population, allowing for millions of different genetic combinations to be passed from parents to offspring. Genetic variability is very important to the long-term survival of a species.
What happens if you have an odd number of chromosomes?
This occurs in about 0.1% of people, and usually causes no effects. In conclusion, humans can have an odd number of chromosomes – but the effects of having an odd number of chromosomes are varied, from being fatal to causing no effect whatsoever.
Why would having an odd number of sets of chromosomes be an issue?
Organisms that have an odd number of chromosomes are usually sterile because their chromosomes cannot be divided evenly during meiosis.
What would happen if the sister chromatid did not split equally during anaphase of mitosis?
If sister chromatids do not split equally during anaphase of mitosis, one daughter cell would have more chromosomes than normal and one daughter cell…
What would happen if one of the sets of sister chromatids didn’t separate during anaphase 2?
Sometimes during anaphase, chromosomes will fail to separate properly. This is called nondisjunction. Nondisjunction results in cells with abnormal numbers of chromosomes. Instead, one pair of sister chromatids failed to split, resulting in one cell with 5 chromosomes and one cell with 3 chromosomes.