They are found in the center of the osteon within a long opening called the Haversian canal.
Answer:
older, older
Explanation:
Fossils deeper in the ground are older.
Answer:
C. Nucleotides
Explanation:
Nucleic acids are macromolecules which are polymers of nucleotides. There are two types of nucleic acids namely: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleotides are the building blocks of nucleic acids.
A nucleotide is made up of three components:
- A phosphate group
- A five carbon sugar called pentose sugar. In RNA the sugar is ribose sugar and in DNA the sugar is deoxyribose sugar.
- Nitrogenous bases: There are four different types of bases in DNA: adenine, guanine, cytosine and thymine. In RNA thymine is replaced by uracil. Adenine and guanine are purines whereas cytosine, thymine and uracil are pyrimidines.
Nitrogenous base and sugar together are called nucleoside and when phosphate is also attached then it is called nucleotide.
