A keystone species is #1 “A species that is very important to the health of a specific ecosystem”
Answer:B
Explanation:
Agonist-induced desensitization involves phosphorylation of G protein-coupled receptors by two currently recognized classes of serine/threonine protein kinases. Second messenger-dependent kinases, phosphorylating a variety of proteins, mediate a generalized cellular hyporesponsiveness termed heterologous desensitization. G protein-coupled receptor kinases (GRKs) phosphorylate specifically agonist-occupied, or activated, receptors, and thereby initiate receptor-specific, or homologous, desensitization.
They all have the same look, same arrangement of bones:and by different shapes and sizes