Answer:
amino groups
amino acids
R groups
Explanation:
I think these are right.
Because a polypeptide chain is polymer of amino acids that are linked together so that mean a polypeptide chain is protien.
To see the difference between <span>biped and a quadruped,</span> let's compare the skeletons of the man (biped) and the horse (quadruped):
*The man has the bigger pelvis: he has to bear the weight of the body.*The scapula is smaller.*The bones of the hind leg bigger.*The forearms more mobile.*The man has the spine that attaches under the skull.*And the tail that has completely regressed.
the man has adapted to standing and biped (he walks on 2 feet): his hind legs are reinforced.
