The beta cells of the pancreas produce insulin, a protein-based hormone. which of the following organelles would be found in higher levels in the beta cells?
a. mitochondria
b. rough endoplasmic reticulum
c. microvilli
d. lysosomes

b. Rough Endoplasmic Reticulum (RER)

Explanation:

In order to answer the question, we need to review the functions of various organelles present in cells.

MITOCHONDRIA:

It is commonly known as the power house of the cell. It is responsible for energy generation in the cell in the form of ATP. Such organelles will be present in large amounts in cells responsible for performing tasks requiring large amounts of energy such as muscle cells.

ROUGH ENDOPLASMIC RETICULUM:

Rough Endoplasmic Reticulum (RER) is endoplasmic reticulum studded with ribosomes. Ribosomes are the protein factories of cells. Hence RER is responsible for forming proteins. Therefore, rough endoplasmic reticulum will be present in large amounts in cells responsible for producing substances rich in proteins like beta cells of pancreas.

MICROVILLI:

These are not organelles but rather cytoplasmic projections/protrusions which increase surface area. They will be present in cells responsible for absorption of substances like cells of small intestine.

LYSOSOMES:

These organelles contain digestive enzymes. They are responsible for degradation of food particles, pathogenic organisms and exhausted cell organelles. They are abundant in cells like macrophages which are responsible for consuming pathogens.

From the above discussion, it is clear that

Rough Endoplasmic Reticulum will be present in large amounts in beta cells of pancreas as these cells secrete insulin which is protein-based hormone.