Macrophages rid the body of worn-out cells and other debris.
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.
De answer is A!!!!!!!!!!!!!!!!!!!!!!!!!!!!
hope it helps!!!!!!!!!!!!!!!!!
a is right!!!!!!!!!!!!!
Answer:
"The fossil plant Elkinsia polymorpha, a “seed fern” from the Devonian period (about 400 million years ago) is considered the earliest seed plant known to date."
