Answer:
They lie flat when we are warm, and rise when we are cold. The hairs trap a layer of air above the skin, which helps to insulate the skin against heat loss. For example, if we become too cold, the hair erector muscles contract.
Explanation:
Answer:
The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies.
Explanation:
Specific immune responses are triggered by antigens. Antigens are usually found on the surface of pathogens and are unique to that particular pathogen. The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies.
The immune system review (article) | Khan Academy
It is poisonous on it's back and is a big species of frogs but not any bigger than a curled up dog.
Answer:
Thermosfere
Explanation:
Temperatures increase in the_Thermosfere __ and troposphere _layers of the atmosphere.
Answer:
similarities
Explanation:
The concept of reproductive isolation relates more toward genetic similarities to distinguish between species. The barriers prevent closely related species living in the same geographical area from interbreeding. They help to keep each species distinct from the others.
