B>encodes the genetic message for the synthesis of new proteins<span>
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Answer:
The question is incomplete.
However, I notice that your question is mainly dealing with
"Nucleotides with a single ring structure"
I tackled that part, also providing explanation to the point you focused on.
Explanation:
Nucleotides are compounds in which nitrogenous bases (purines and pyrimidines) are conjugated to the pentose sugars (ribose or deoxyribose) and at least one phosphate group. Thus a nucleotide consists of a nitrogenous base, pentose sugar and at least one phosphate group.
Examples of the nitrogenous bases are Adenine, Guanine, Thymine, Uracil and Cytosine. Of all, Thymine, Uracil and Cytosine are with single ring, while Adenine and Guanine are double ring structure.
So in order to form a new organism, two gametes -- the sex cells, sperm and egg -- must fuse, further mixing the genes to produce more genetic diversity. Asexual reproduction is one organism dividing into two organisms without shuffling its genes, so the offspring has the same version of genes as did the parent.
Because most waste produced in the cell is toxic when it accumulates.
Hope this helps!