Sexual reproduction leads to genetic variation because the sperm and egg that are produced contain different combination of genes than the parent organisms. sexual reproduction involves meiosis which is in the process of a cell doubling its DNA.
The answer would be: relatively constant environmental conditions
When the environment condition is changed, the organism need to changes too. If the organism reproduced asexually, their genetic material of the offspring would be identical without change. This makes asexual reproduction couldn't produce a different offspring.
Sexual production will produce a various genetic material that might turn the changes into beneficial condition.
Cytokinesis. The final cellular division to form two new cells. In plants a cell plate forms along the line of the metaphase plate; in animals there is a constriction of the cytoplasm. The cell then enters interphase - the interval between mitotic divisions.
