Biology CLEP Prep Practice Exam

What organelle is the site of protein production?

1. Ribosome

2. Nucleus

3. Chloroplast

4. Mitochondria

The correct answer is: Ribosome

Ribosomes are the organelles responsible for protein production in a cell. They are found in both prokaryotic and eukaryotic cells and can be found free-floating in the cytoplasm or attached to the endoplasmic reticulum. Ribosomes use the genetic information from mRNA to synthesize proteins. The nucleus is responsible for housing and protecting the genetic material of the cell, the DNA, and does not directly participate in protein production. Chloroplasts are only found in plant cells and are responsible for photosynthesis, a process that produces glucose, not proteins. Mitochondria are responsible for producing energy for the cell through cellular respiration, not protein production.