The pectoralis major is a big chest muscle otherwise known as your pecs (lol)
and it helps the arms so i would say pushups.
Answer: Option B) Antigens
Blood typing is based on the presence of proteins known as antigens on the outer surface of the red blood cell plasma membrane.
Explanation:
Blood groups A, B, AB, and O are determined based on the antigen-antibody reactions between donor and recipient bloods.
For instance,
- Blood type A has antigen A on its plasma membrane
- Blood type B has antigen B on its plasma membrane
- Blood type AB has both antigen A and antigen B on its plasma membrane
- while blood type O has neither antigen A nor B on its plasma membrane
So, antigens is the answer
C. Genetic variation
Bacteria are very numerous, and random mutation of bacterial DNA generates a wide variety of change, including resistance. It happens through mutation and selection. Not only are they capable of sharing genetic bits of DNA to related and unrealted species they can develop ways to remove the antibiotic before it reaches its intended area via biochemical pumps or enzymes to inactiavte the antibiotic.
