Answer:
D
Explanation:
It is the endoplasmic reticulum and the ribosomes of the specialized cells in the pancreas that make insulin. Remember, most human cells make proteins at the protein factory called the ribosome. This ribosome is either free floating in the cytoplasm, or is attached to the endoplasmic reticulum.
The genes for making insulin lie in the DNA of these pancreatic cells. Normally, they should only be turned on inside these particular cells.
When they are turned on, RNA is transcribed and then protein.
That particular protein is insulin.
Remember insulin acts as a hormone.
By the way,the beta cells in the islets of Langerhans make insulin.
