Invading microorganisms sometimes enter the body and threaten its health. how does the body protect itself from these invaders?

a.
the immune system kills or disables the invading organisms.

b.
the respiratory system removes invaders from the blood.

c.
the immune system collects and stores the invading organisms.

d.
the respiratory system surrounds the invaders with carbon dioxide.

Water changes bacteria in the soil converts this nutrient into a usable form. plants take up the usable nutrient through the soil and assimilate it into proteins, making it part of the plant. an animal eats the plants, and the nutrient becomes part of the animal. when the animal dies, it decomposes, returning the nutrient back to the soil. which cycle is being described? water cycle carbon cycle nitrogen cycle phosphorous cycle