Proteins are formed by ______ different amino acids.

Metabolism is the sum of

When two atoms are held together because their valence electrons are attracted by opposite charges, they are united by

Mis abuelos paternos no ___________ de este país.

Tú ______________________ una bicicleta, ¿verdad?  

Mujer de Guatemala

Calcium homeostasis in adults is maintained mainly by

If bacteria were to invade the Central Nervous System, microglia cells would migrate to the area to engulf and destroy them.

Which one of the following does not have an abundance of collagen fibers?

A shallow, broad, or elongated basin (depression) in a bone is called a(n)