Answer:
a.There are three signaling pathway
1- Reception in which molecule binds to receptor
2- Signal transduction in which activation of intracellular pathway and enzyme occur.
3- Cellular response in which specific response of cell occur according to receptor and ligand.
b. Three types of receptors are
1- autocrine
2- paracrine
3- endocrine.
Explanation:
autocrine receptors are signaling pathway in which cell releases its molecule and bind to its own cell receptor example cancer cells while paracrine in which ligand binds to other nearby cell receptor and it is used during development and in endocrine cell target distinct cell and travel through blood stream like hormones functioning.
Answer:
The Nitrogen Returns into the Soil (Nitrogen Cycle)
Explanation:
After a plant dies it's the job of a decomposer to carry along the nitrogen back to the surface so that it may continue to cycle along, until it eventually returns back to the decomposer through the death of another plant. This part of the cycle is small compared to the whole Nitrogen cycle.
I have I pineapple I have a pen...I forgot the rest
The answer is : ingestion and digestion
; propulsion and secretion
; absorption and elimination
Digestive system will receive and digest food to make the molecule smaller. After the molecule become small, it could be absorbed by the body. The waste that couldn't be digested and absorbed will be eliminated as feces. Some of the waste from the body like bilirubin would be dumped through feces too.