The small intestines have microvilli in the lining which help to increase the surface area of the small intestines and help to absorb nutrients.
Thymine and cytosine are classified as "Pyrimidines" and have one ring of carbon and nitrogen atoms for each base.
Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. Both also contain similar membranes, cytosol, and cytoskeletal elements.