Answer:
a. antigen
Explanation:
The Immune system is composed of immune cells that defend the body against foreign substances such as bacteria or virus. Lymphocytes (B and T cells) are one of the main immune cells
Lymphocytes have the ability to recognize and bind to antigens, wich are substances foreign to the body ( i.e bacterial or virus elements) that evokes an immune response.
Answer:
The sympathetic nervous system is involved in preparing the body for stress related activities; the parasympathetic nervous system is associated with returning the body to routine, day-to-day operations. The two systems have complementary functions, operating in tandem to maintain the body's homeostasis.
Hello to answer your question.
A is correct
But more likely forest fires would be the culprit because the trees produce O2
so when the are burnt, it would be like everybody o this earth breathed out at once causing CO2 to be released in to the atmostphere in a big burst
Signed by, Virtuoso Sargedog
Because they have not been distrubed
A situation where friction would be desirable is rubbing your hands together to make them warm in the winter time.