The two factors are: crossing-over and independent assortment. Crossing over: In Prophase I of Meiosis I, homologous chromosomes line up their chromatids and “cross-over”, or exchange corresponding segments of DNA with each other. This produces genetic variation by allowing more combinations of genes to be produced.
What are two ways meiosis introduces genetic variation?
We have seen that meiosis creates variation three ways: crossing over, mutations caused during crossing over, and independent assortment.
What two processes contribute to genetic variation?
Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism’s offspring).
How does the process of meiosis lead 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.
How does meiosis 1 and 2 cause genetic variation?
Complete answer: Meiosis also induces genetic variation by means of the recombination process. Later, as two gametes combine during fertilization, this variation is increased even more, thereby producing offspring with special DNA combinations.
Why is genetic variation in meiosis important?
Meiosis is important because it ensures that all organisms produced via sexual reproduction contain the correct number of chromosomes. Meiosis also produces genetic variation by way of the process of recombination.
What type of cells does meiosis produce?
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 are the 3 types of genetic variation?
For a given population, there are three sources of variation: mutation, recombination, and immigration of genes.
Which factors contribute to genetic variation in humans?
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.
What are the causes of variation?
The two main causes of variation are mutation and genetic recombination in sexual reproduction.
What are the phases of mitosis?
These phases are prophase, prometaphase, metaphase, anaphase, and telophase. Cytokinesis is the final physical cell division that follows telophase, and is therefore sometimes considered a sixth phase of mitosis.
Which process leads to the most genetic variation?
The answers are crossing over, independent assortment of chromosomes in meiosis and random fertilisation. Crossing over, especially, causes genetic recombination and results to traits that are different from either parents. Another process that leads to genetic variations is genetic mutations.