Frequent question: How does meiosis II contribute to genetic variation?

By meiosis II, only sister chromatids remain and homologous chromosomes have been moved to separate cells. Recall that the point of crossing over is to increase genetic diversity. If crossing over did not occur until sometime during meiosis II, sister chromatids, which are identical, would be exchanging alleles.

How does meiosis relate to genetic variation?

Genetic variation is increased by meiosis

Because of recombination and independent assortment in meiosis, each gamete contains a different set of DNA. This produces a unique combination of genes in the resulting zygote. Recombination or crossing over occurs during prophase I.

What best describes how meiosis contributes to genetic variation?

During meiosis, homologous chromosomes (1 from each parent) pair along their lengths. The chromosomes cross over at points called chiasma. At each chiasma, the chromosomes break and rejoin, trading some of their genes. This recombination results in genetic variation.

What are three ways meiosis leads to genetic variation?

Genetic Variation

  • mutation.
  • random mating between organisms.
  • random fertilization.
  • crossing over (or recombination) between chromatids of homologous chromosomes during meiosis.
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Why meiosis leads to significant genetic variation while mitosis does not?

5. Assess how meiosis contributes to genetic variation, while mitosis does not. During meiosis, the independent assortment of the pairs of chromosomes and crossing over provide a large amount of genetic variation. Mitosis produces identical cells.

What does the process of meiosis contribute to?

Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells. This process is required to produce egg and sperm cells for sexual reproduction.

What causes genetic variation?

Mutations, the changes in the sequences of genes in DNA, are one source of genetic variation. Another source is gene flow, or the movement of genes between different groups of organisms. Finally, genetic variation can be a result of sexual reproduction, which leads to the creation of new combinations of genes.

Which of the following best describes the difference between meiosis I and meiosis II?

In meiosis I, homologous chromosomes separate, while in meiosis II, sister chromatids separate. Meiosis II produces 4 haploid daughter cells, whereas meiosis I produces 2 diploid daughter cells. Genetic recombination (crossing over) only occurs in meiosis I.

Why should meiosis 2 occur when a reduction in the chromosome number has already occurred in meiosis 1?

Answer: Because meiosis creates cells that are destined to become gametes (or reproductive cells), this reduction in chromosome number is critical — without it, the union of two gametes during fertilization would result in offspring with twice the normal number of chromosomes!

Which two stages are most responsible for the genetic variation observed within a species?

Meiosis is the stage of cell division which is responsible for Genetic Variation And Evolution of Species. EXPLANATION: The word meiosis is come from the Greek word meioun. It means “to make small”, it shows the special process by which the germ cells divide into the produce gametes.

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Which step of mitosis leads to significant genetic variation?

In prophase I, homologous chromosomes pair up and ‘crossing over’ occurs, during which sections of one chromatid may break off and reconnect to the other, swapping DNA (this contributes to genetic variation in the haploid daughter cells).