A. Trees regain their leaves
Answer:
A producer. For example in a common food chain, grass->grasshopper->mouse->snake->eagle. The grasshopper eats grass which is a producer so if there aren't anymore insects like grasshoppers, then the grass grows more.
A bold eagle if your trying to be funny lol
Characteristics should be in the blank
Answer and explanation:
Antibodies are structures made of four polypeptides, <em><u>two light (L) chains and two heavy (H) chains that join together and form a molecule shaped like a "Y"</u></em>. This structure is possible thanks to the <u>disulfide bonds</u> that bind light chains and heavy chains together. While the stem of the Y is constant and doesn't change ("<em>constant region</em>"), the tips of the Y, composed of 110-130 amino acids and called "<em>the variable region</em>", vary greatly among the different antibodies and are responsible for the high specificity of these molecules.
<u>This is why we could say that the primary structure of this protein is given by disulfide bridges that twist the antibody and allow it to bind to a protein from the flu virus.</u>