Nucleic acids also typically contain phosphorous, and nitrogen plays an important structural role in nucleic and proteins. The proteins, being made up a diverse set of amino acids, have, in addition to carbon, hydrogen, oxygen, and nitrogen, the elements sulfur and selenium.
Jawless fish. The class Agnatha is a class made up of jawless fish. It excludes all vertebrates with jaws.
It's the crystal <span>quartz.</span>