nucleic acids. certain proteins. cell membranes. certain carbohydrates.
Answer:
Reptiles
Explanation:
Vertebrate paleontology covers everything from the tiny, fish-like creatures, to the salamander-like ancestors of all land vertebrates, to dinosaurs, mammals, flying and swimming reptiles, etc.
Hope this helped
The answer is immune system
Answer:Specialized cells perform specialized functions in multicellular organisms. Groups of specialized cells cooperate to form a tissue, such as a muscle.
Explanation:
The statement which best explains why carbon is present in so many kinds of molecules is because <u>it can form four covalent bonds.
<em /></u>It isn't rare on Earth, so A is incorrect. It has valence electrons, so C is incorrect. It cannot become an ion, so D is incorrect.<u>
</u>
