Ragweed antigens bind ragweed and then bind mast cells which release histamine
<span>Allergies develop because of a Th2 response against the allergen. </span>
Answer:
This is a picture of an aminoacid chain
Explanation:
In an amino acid chain all amino acids ( for example GLY, VAL, or ARG) are linked by peptide bonds. Long chains, also called polymers, of amino acids are called proteins. The enlarged photo is an example of a structure of an amino acid. They have an amine (-NH2) and carboxyl (-COOH) functional group, along with a side chain (R group), specific to each amino acid.
Answer:
Veins
1l carry blood from tissue of the body to the heart
2) are usually found closer beneath the skin
3) are less muscular then arteries
4) collapse if blood flow stops
arteries
1) carry blood back away from the heart to the tissue of the body.
2) found deeper within the body
3) are more muscular then veins
4) would generally remain open even if blood stops because of it's muscular structure.
Natural selection is species survival and reproduction due to differences in some traits that give them an advantage over others