Antibodies, also called immunoglobulins, are proteins manufactured by the body that help fight against foreign substances called antigens. When an antigen enters the body, it stimulates the immune system to produce antibodies. (The immune system is the body's natural defense system.) The antibodies attach, or bind, themselves to the antigen and inactivate it.<span>
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Answer:
The correct answer is D. is a facultative anaerobe
Explanation:
A facultative anaerobe is the organisms that can live in the absence of oxygen but prefer to utilize the oxygen when oxygen is present in the environment.
An anaerobic organism requires more amount of energy sources like carbohydrates because they use the fermentation process to make energy and this process results in the formation of less energy than aerobic respiration.
All the bacteria of family Enterobacteriaceae that live in the intestine are facultative anaerobes. Therefore facultative anaerobe can thrive in both the presence and absence of oxygen so the correct answer is D. is a facultative anaerobe.
<span>Axial Skeleton; the axial skeleton includes the skull and sine while the appendicular skeleton includes the limbs and the bones with which they attach to the axial skeleton.</span>