Growth factors and cytokines both lead to tyrosine phosphorylation through receptors, but they do so through different mechanisms. what is the key difference between the receptors for these two classes of ligands in terms of their tyrosine kinase activity?

The growth factor receptors have a kinase domain while the Cytokines receptors do not contain a kinase domain as part of their structure.

Explanation:

The two are signaling molecules that control cell activities in some manners, such paracrine, endocrine and autocrine manners.

The receptor kinase domain can be specific for substrate sites in which phosphorylation occurs.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

explanation:

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.