Answer: 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).
By the end of meiosis, the resulting reproductive cells, or gametes, each have 23 genetically unique chromosomes. The overall process of meiosis produces four daughter cells from one single parent cell.
Explanation:
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.
Answer:
The correct answer is ecological isolation.
Explanation:
The condition when two species in spite of living in the same region, exhibits certain characteristics, which inhibits them from mating with each other is termed as reproductive isolation. The obstructions or the causes that prevent them from interbreeding is known as isolating mechanisms.
The given case is an example of ecological isolation and is one of the forms of reproductive isolation. Habitat or ecological isolation refers to the phenomenon in which two species cannot mate with each other as they thrive in two distinct locations. Like as mentioned, two species of garter snakes though coming from the same geographical area cannot interbreed, as one of them is living in the land and the other one in the water.
No new substance is produced.
