Please tell this few question ans
In asexual reproductionn the offsprings are almost identical to their parent because they have the same genes as of their parents. Thus, genetic variation is not possible or is slow in asexual reproduction.
1. Sexual reproduction involves fusion of male and female gametes coming from both the parents. This is because the offsprings receive some genes from mother and some from father.The mixing of these genes of mother and father in various different combinations, results in the offsprings having genetic variation.
Thus, we conclude that sexual reproduction promotes diversity of characters in offsprings by providing genetic variation. This genetic variation leads to continuous evolution of various species to form better and still better organisms.
5. As per the Darwin's theory of evolution by Natural selection, individuals advantageous variations are more likely to survive and reproduce than those without the advantageous variations. Over the generations this process of natural selection will lead to a continuing gradual change of population, that is evolution, and to the production of new species.For example, the heritable variation in neck length exists in the ancestral population of giraffes was relatively short, but during times of food scarcity, the longer necked animals were able to exploits food resources that were unavailable to the shorter necked ones tend to survive and perpetuate their own kind in much greater numbers than the shorter necked ones. After many generations the descendent population has a much longer average neck length.
Thus, selection of variants by environmental factors forms the basis for evolutionary processes.
* For rest of the queries please post separately.
Regards