1. These systems are similar because they both have a receptor protein on the outside of the cellular membrane that starts the signal transduction pathway. Also, both use phosphate groups to activate proteins in the pathway.
2. The two are different as G-protein receptor systems use a protein to move the signal along. The tyrosine kinase receptor system uses kinase to give many proteins a phosphate group to activate them. This boosts the signal faster in the tyrosine kinase system over the G-protein.
3. Amplification occurs when one activated protein, signals another two proteins to activate, which those then both activate another two proteins, and so on and so forth, amplifying the signal.
a. I would look for a receptor that can bond with a variety of what can signal it, along with the receptors each having a different variety.
b. Dogs may have may more receptors than humans so they have a higher chance to receive a signal.