That isn't even a question
Answer: D. It increases the bird's chances of finding a mate.
Explanation:
As the question states, it's beautiful for the mate to see.
Answer:
any of numerous complex proteins that are produced by living cells and catalyze specific biochemical reactions at body temperatures
Answer: False
Explanation: The COMPLEMENT SYSTEM consists of proteins synthesized in the liver. They are activated by inespecific harmful substance (antigen) and begins a cascade of proteins that finally forms an attack complex against bacteria.
The COMPLEMENT is part of the INNATE IMMUNITY, because it is an inherent response, something all humans born with, and it is part of the first defense barrier against any antigen. Part of the innate immunity are too: natural killer cells, neutrophils, monocytes, dendritic cells and macrophages.
On the other hand, the ADAPTATIVE IMMUNITY, is the response that the body develops after being exposed to an antigen before. It is like something that the body recognizes, and then "learns" how to act against it. Part of the adaptative immunity are: lymphocyte T and B, and the antibodies (substances called Immunoglobulins). The immunoglobulins (Ig) are glycoproteins present in the blood.
Normally, people produce about 100 billion white blood cells a day. ... However, an increase in the number of white blood cells is also caused by cancers of the bone marrow (such as leukemia) or by the release of immature or abnormal white blood cells from the bone marrow into the blood.
Overview of White Blood Cell Disorders - The Merck Manuals
https://www.merckmanuals.com/.../blood-disorders/white-blood-cell-disorders/overview-...