The correct answer to this question would be "B", co-dominance.
Answer:
G-protein-linked receptor
Explanation:
Epinephrine acts via G-protein-linked receptors. The heterotrimeric G proteins located within the cell are activated by G protein-coupled receptors that span the cell membrane. Signaling molecules bind to a domain on the GPCR located outside the cell, and an intracellular GPCR domain then in turn activates a particular G protein.
When organic molecules decompose, energy is released.
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.