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.
At this point the enzyme is denatured.
<span>Regions of DNA that read the same regardless of the direction are called Palindromes. The sequence of nucleotides is the same whether you start from the 3' end or the 5' end. Palindromes may occur due to chromosomal inversion or due to breakage.</span>
1. D
2. B
Those are your answers hope this helps!!