What processes contribute to genetic diversity?
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 do meiosis I and II contribute to genetic variation?
Because the duplicated chromatids remain joined during meiosis I, each daughter cell receives only one chromosome of each homologous pair. By shuffling the genetic deck in this way, the gametes resulting from meiosis II have new combinations of maternal and paternal chromosomes, increasing genetic diversity.
What best describes how meiosis contributes to genetic variation?
The replicated homologous pairs of chromosomes join together during “synapsis“. Here, sections of chromosomes are exchanged. The end result includes chromosomes with genes from both parents, which increases genetic variation. The process of synapsis and crossing over only occurs in sexual reproduction (meiosis).
What two processes increase genetic variation?
Two processes are responsible for genetic variation, recombination (the subject of this chapter) and mutation. Mutation is the ultimate source of genetic change; new alleles arise in all organisms, some spontaneously, others as a result of exposure to mutagenic agents in the environment.
Which two phases of meiosis are most responsible for the variation in gametes quizlet?
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 the three major contributors to genetic diversity?
For a given population, there are three sources of variation: mutation, recombination, and immigration of genes. However, recombination by itself does not produce variation unless alleles are segregating already at different loci; otherwise there is nothing to recombine.
What are the 3 events in meiosis that contribute to genetic variation?
The three main sources of genetic variation arising from sexual reproduction are: Crossing over (in prophase I) Random assortment of chromosomes (in metaphase I) Random fusion of gametes from different parents.
What are the three mechanisms that contribute to genetic variation?
Let’s examine three mechanisms that contribute to the genetic variation arising from sexual reproduction: independent assortment of chromosomes, crossing over, and random fertilization.
How does meiosis 1 contribute to genetic variation?
During prophase of meiosis I, the double-chromatid homologous pairs of chromosomes cross over with each other and often exchange chromosome segments. This recombination creates genetic diversity by allowing genes from each parent to intermix, resulting in chromosomes with a different genetic complement.
How does meiosis relate to genetic variation?
Specifically, meiosis creates new combinations of genetic material in each of the four daughter cells. These new combinations result from the exchange of DNA between paired chromosomes. Such exchange means that the gametes produced through meiosis exhibit an amazing range of genetic variation.
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.