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.
Approximately one billion oxygen molecules. that is because there are about 250 million molecules of haemoglobin in each cell, and each haemoglobin molecule binds to 4 oxygen molecules
Answer:
B.
Explanation:
the sun is solar power which gives you natural energy
The difference between active and passive cellular transport is that active transport requires energy for the ions and molecules to move across the cell membrane whereas passive cellular transport does not an energy input.