Answer:
Receptors are highly specific and only have high affinity for those ligands for whom they are specific.
Explanation:
Receptors are proteins that receive a stimulus or bind a ligand and mediate effects via receptor effector system.
Receptors are macromolecules that are highly specific.
The affinity between the ligand and the receptors is determind by the disassociation constant Kd.
The receptors produce maximun effect when an appropriate specific stimulus is present.
Different recptors types are present for different ligands.
For example, muscrinic receptors are specific for acetycholine and adrenergic receptors are specific for adrenaline/nor adrenaline.
It is important to know the specificity so that the body remains in a state of balance.
1. One reason is extinctions happen because of some kind of change in the environment where a life form lives. While some species can adapt to the changes, others die, and if enough die, the species becomes extinct. These are some of the biggest factors in the extinctions of particular species. 2. Contaminants in the environment, such as pesticides.
It's not.
If the plants are growing under the ice and the ice is floating above it on the surface of the water and the ice blocks the light from getting to the plant.