Different cell types are specialized to respond to signals in different ways regardless of the receptor because the intracellular signals produced are interpreted differently in cells specialized for different functions.
Explanation:
Different cells types with the same kind of receptor for signals can induce different phenotypes due to difference in the intracellular responses produced by the cell types because of the difference in functions performed by the cells. For example, acetylcholine binds to similar receptors in different cell types but illicit different response in them. Acetylcholine signals in heart muscle cells cause reduction in the rate and force of contraction of the heart; also acetylcholine cause secretion in the salivary gland cells; also contraction upon introduction into the skeletal muscle cells despite binding to similar receptors in all the cell types mentioned. The response produced are as a result of the different specialized functions performed by those cell types not minding the receptor component and its foreknown action.
It is possible since a receptor can activate different signaling pathways in different cell types
Explanation:
In a cell, a receptor bind to a specific ligand to activate a signaling pathway, while the same receptor may bind either with the same or another ligand in another cell type and thus activate another signaling pathway
The answer for this question would be the second option. Genomic studies cover the analysis of the changes of genome by scanning the markers across complete sets of DNA. Based on these studies, the change in gene sequences happen that resulted to a change in the way that the brain interprets speech in between 4 and 9 million years ago.
