Question

What organelle would you expect to be most common in the cells of the following structures and why?

a. Liver

b. Muscle

c. Pancreas

d. Testes

e. leaf

Answer 1

Answer -Endoplasmic reticulum.  

The primary function of cells is really to make things, mostly proteins. Using instructions from the same DNA (deoxyribonucleic acid) that carries the genetic code for the entire organism, structures called ribosomes manufacture individual proteins. Some proteins become incorporated into cells, tissues and organs. Others are destined to become enzymes.

In eukaryotes, many of these ribosomes are attached to a "highway-like" membrane-heavy feature called the endoplasmic reticulum. This comes in two types, "smooth" and "rough." The cells of the liver, ovaries and testes have a high density of smooth endoplasmic reticulum (smooth ER, or simply SER), whereas organs that secrete a great deal of protein, such as the pancreas, have cells rich in rough endoplasmic reticulum (rough ER, or simply RER).