<u>Answer:</u>
Organisms C and D are more closely related than
Organisms A and B
<u>Explanation:</u>
Organisms A and B are not related much as the distance between them is more than the organisms C and D so the C and D are closer than A and B. The phylogenetic tree shows the biological evolutionary relationship among various biological species. So the given tree shows the relationship as mentioned above.
It also show the physical and genetic relationship among the various biological species. The phylogeny is generally shown by using a particular phylogenetic tree. For example, the simple one below which describes the different evolutionary relationships between the great apes. The genus Pongo includes orangutans, Pan includes chimpanzees and bonobos, and Homo includes humans, while Gorilla is self-evident.
Explanation:
The modern theory of chemical evolution is based on the assumption that on a primitive earth a mixture of simple chemicals assembled into more complex molecular systems, from which, eventually came the first functioning cell(s).
The most true answer from these choices is:
Methyl groups most often added to guanine-cytosine base pairs because they are held by three hydrogen bonds, and this decreases the probability of gene expression.