Question

Read the passage and answer the following question.

Ribosomes are the smallest cell organelles which can be seen only through an electron microscope. They are found in both prokaryotic as well as eukaryotic cells. Ribosomes are dense, round bodies which occur freely in the cytoplasm and may remain attached to the surface of the endoplasmic reticulum. Chemically, ribosomes are made up of ribonucleoprotein (in eukaryotic cells, the constituent of the ribosome is 40% protein and 60% ribosomal RNA). Ribosomes help in the process of protein synthesis. They are, therefore, called as the protein factories of the cell.

Which of the following is called as "protein factories of the cell"?

• A. Ribosome
• B. Mitochondria
• C. Plastids
• D. Lysosome

Answer 1

Answer: (A)

Ribosome

Ribosomes are found in both, prokaryotes and eukaryotes. The ribosome is the site for protein synthesis. Thus, it is also known as protein factory. They are complexes of proteins and three (prokaryotes) or four (eukaryotes) rRNA molecules called as subunits. The main function of ribosomes is the site of mRNA translation; once the two subunits are joined by the mRNA from the nucleus, the ribosome translates mRNA into a specific sequence of amino acids.