Layering.
Hope this helps (:
-Payshence xoxo
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.
In the small intestine, these cells contain microvilli, which are tiny hair-like projections that increase nutrient absorption. These projections increase the surface area of the small intestine allowing more area for nutrients to be absorbed.
The earliest forms would be plants and other life like that, and current day would be mostly humans and animals and a lot of plants are disappearing
Most likely showing your work would contain self checks, so study guides?
