Barry is a vegan. his diet does not include foods that contain preformed vitamin a, and he does not take any vitamin a supplements.

How are proteins and nucleic acids related? they both provide energy. they both carry genetic information. the structure of proteins is determined by nucleic acids. the subunits of nucleic acids are also the subunits of proteins.

Why do we perceive objects as retaining their brightness under different lighting levels?

Which kingdom includes some organisms that have no nucleus and can live in an environment with an extremely high salt content