The answer is; E
This shows that these organelles were once free-living organisms with their own mechanisms for reproduction which they have retained even after years of symbiotic relationship with the higher organisms. During their duplication, they also replicate their own DNA. Their DNA does not have histones (as opposed to the DNA in the nucleus of their host eukaryotic cell) similar to that of simple organisms such as bacteria.
Only unicellular orgaimns I might be wrong
The environment provides the selective pressure in natural selection. Artificial Selection is a type of choice in which people effectively pick which characteristics ought to be passed onto posterity. People have utilized particular rearing some time before Darwin's Postulates and the disclosure of hereditary qualities. It is the rearing of plants and creatures to deliver attractive qualities. Living beings with the coveted characteristics, for example, size or taste, are misleadingly mated or cross-pollinated with creatures with comparable wanted attributes.
