Natural selection allows nature to chose which species survives. Only the fittest get to pass on their genes. And by fittest i mean the ones that are better adapted to the environment.<span />
Answer:
Part A: The process of sexual reproduction is important because by this process organisms with varied genetic characteristics can be formed. Crossing over and independent assortment allow individuals to be born which are not alike to another and their parents. As a result, genetic diversity is produced.
Part B:
The process 1 is meiosis. The process 3 is development by mitosis.
The reproductive organs form sperm and egg by the process of meiosis. During this process, the number of chromosomes is reduced so that the number of chromosomes of an individual can be maintained.
The zygote converts into an embryo in a process called germinal development. The zygote replicates by mitosis to form into an embryo.
The planets appeared to move backward in the sky occasionally.