Without genetic variation, a population cannot evolve in response to changing environmental variables and, as a result, may face an increased risk of extinction. For example, if a population is exposed to a new disease, selection will act on genes for resistance to the disease if they exist in the population.
So, as you know, when a sperm cells (Male sex cell) meets the Egg cell (Female Sex Cell) it forms something called a zygote. And from that point on, the egg cell reproduces more and more (making more cells) in a type of cell called a stem cell, which can be used for anything the body needs. The newborn babies keep these cells up until birth or the incubation (growth of the baby in the mother's uterus), and then they are ready to be born.
The Answer is A Birds because birds use eggs not sex
They are examples of precipitation
Elephants, who are important grazers, are instrumental in transforming woodlands into grasslands. This has a tremendous impact on other species that depend on the grass for their survival. The significance of the elephant in this example is B. keystone species.