Evolution occurs when<span>these heritable differences become more common or rare in a population, either non-randomly through natural selection or randomly through genetic drift
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Mitochondria :) your welcome
Answer:
The correct answer is B.
Explanation:
Given the baltimore's scheme which used for virus classifications, the most closely related option of virus to the described polio virus with a single stranded RNA in the question would be retroviruses that require a DNA intermediate.
Because much like the single-stranded RNA viruses, the retroviruses do not contain any DNA but they do have an enzyme named reverse transcriptase which they can use to replicate their RNA into the host cells DNA and use the end product for their benefits. So they both work in similar ways.
I hope this answer helps.
