Explanation:
DNA has three types of chemical component: phosphate, a sugar called deoxyribose, and four nitrogenous bases—adenine, guanine, cytosine, and thymine. Two of the bases, adenine and guanine, have a double-ring structure characteristic of a type of chemical called a purine.
Nucleic Acids are made up of repeating units called Nucleotides
As newer rock layers form, they overlap with the ones with the pre-existing ones. Therefore, when looking for older rock layers, we would look for the ones that are deeper beneath the surface of the earth. On the other hand, newer rock layers are found at the top. This is also observed in the fact that oil rigs dig very deep into the ground to access the layers that are millions of years old.
Answer:
they contain hymoglobin
Explanation:
the red pigment in blood cells