Answer:
A nucleotide is one of the structural components, or building blocks, of DNA and RNA. A nucleotide consists of a base (one of four chemicals: adenine, thymine, guanine, and cytosine) plus a molecule of sugar and one of phosphoric acid.
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Transitional fossils</h3>
Transitional fossils are any fossilized remains of a life form which show common traits to both an ancestral group and its derived descendant group.
<em> Australopithecus afarensis </em>is a hominid that represents an evolutionary transition between modern bipedal humans and their quadrupedal ape ancestors.
Similarities in DNA
All species in the world share some amount of DNA. Species that are more related to each other share bigger amount of DNA than species that are less related. For example fruit fly and modern humans share 61% of their genome and chimps and humans share 96%.
Evolution of the eye
The PAX6 gene controls where eyes develop in animals ranging from fruit flies, octopuses, to mice and humans.
It's has an important role in the survival and adaptability of a species. When a species habitat changes, the population needs to be able to adapt to survive: the ability of the population to adapt to the changing environment will determine their ability to cope with an environment challenge.