How does your body obtain amino acids that cannot be made in cells ?

Why do farmer's kill animals in a mean way, don't farmer's have feeling's?

What would happen if you ate the number of calories of someone who is much taller and more active than you are?

Which of the following human diseases is caused by a virus that requires reverse transcriptase to transcribe its genome inside the host cell? a) herpesb) aidsc) smallpoxd) influenza