Phagocytosis and the inflammatory response. Macrophages are a cornerstone of the innate immune system. ... Recent work indicates that Toll-like receptors play a key role in reading a "bar code" on invading microorganisms and in eliciting a specific immune respone.
(C) earth's outer iron core
this is because iron is magnetic and therefore forms a strong magnetic field
Answer: synthesis of DNA from an RNA template
Insects, and some other invertebrates, exchange oxygen and carbon dioxide between their tissues and the air by a system of air-filled tubes called tracheae. Tracheae open to the outside through small holes called spiracles.