The correct answer is: A. The genes for insulin production are not activated in heart cells.
Explanation:
<u>DNA </u><u>is present in practically every cell in an organism</u>, but not every cell performs the same tasks as the rest. This happens because genes in the DNA <u>code for different types of proteins</u>, from enzymes to transporters, that impact greatly on the <u>function</u> of a cell; and these genes can be activated or inactivated which will directly correlate to the type of cell and the function that it has.
<u>If the cells in the pancreas can produce insulin but the cells in the heart can't it's because the cells in the heart have the genes for insulin production inactivated</u>.
The amount of mitochondria and ribosomes does not directly affect the production of insulin.
The tissue you are referring to here is the xylem, a <u>vascular tissue</u>, whose basic function is to transport water and nutrients from the roots to the rest of the plant.
This is allopatric speciation. The organisms were separated from each other by the containers. The separation caused them to evolve to the point that they were more likely to mate with each other than with a member of another tank.