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.
This is false the population density will decrease as the area decreases
Lignin
It is a complex organic polymer that form an important structural materials in the support system of vascular plants and can also be found in some algae. This is an important molecule in the structural composition of cell wall, such as in wood and bark. This also allow woods and barks to have strong, rigid which allows them to no break easily. Lignin can also be found inserted in the cell wall of this plants.
<span>Each of the protein chains are conjugated to a nonprotein heme group.Hemoglobin is
the protein that's made of the four polypeptide chains. Each of these chains contains a heme group. Red blood cells are primary players in the oxygen hauling, and they wouldn't be able to do their job if it the weren't for a special molecule called the heme.</span>
Undisturbed rock formations on mountain tops are basically an indication of the Earth's age. This can be supported by the law of proposition. This law states that the youngest sediments or rock are found at the top of the sequence and the oldest are found at the bottom - given they're undisturbed. So the higher mountain tops or rocks formation are, the more we can say that the Earth is indeed very old.
