The answer is A: Mass extinction.
"Abrupt disappearance of many land and marine species" = extinction of many species.
The Law of Superposition.
The Law of Superposition states that each layer is younger than the one beneath it.
Answer:
Answer is D - cAMP.
Explanation:
cAMP is a small molecule that functions as an intracellular signaling molecule - a second messenger. The first messenger would be the thing that activated the GPCR (e.g. a hormone). The GPCR is a signal transducer (converts extracellular signal to intracellular signal). Once activated, the GPCR activates adenylate cyclase which can be called a signal effector - it is an enzyme that produces cAMP.
The side of a mountain range that faces the wind often receives more moisture then the downwind of the same range
