The function of ribosome in cells is

1. Analyze the question You are asked for the main function of the ribosome, a small organelle found in all cells.

2. Explain the concept Ribosomes are tiny structures made of ribosomal RNA (rRNA) and protein. They are found:

• free in the cytoplasm, and
• attached to the rough endoplasmic reticulum (which is why it looks "rough").

Their job is translation. They read the message carried by messenger RNA (mRNA) and join amino acids together in the correct order to build polypeptides (proteins). Because of this, they are often called the "protein factories" of the cell.

3. Work through the options

• A. Protein synthesis: Correct. This is the main function of ribosomes.
• B. Starch synthesis: Wrong. Starch is made in plants, in chloroplasts and amyloplasts, not by ribosomes.
• C. Transport of material: Wrong. This is done by the endoplasmic reticulum, the Golgi apparatus (packaging and secretion), and vesicles.
• D. Lipid storage: Wrong. Lipids are stored in lipid droplets, and the smooth ER is involved in lipid synthesis. Ribosomes are not.

4. Answer The correct option is A. protein synthesis.

5. Exam tip Link each organelle to its job:

• Ribosome → Read mRNA and build Proteins
• Mitochondria → Make energy (ATP)
• Golgi → Gift-wrap and send out
• Chloroplast → photosynthesis

Whenever you see "ribosome" in a JAMB question, think "protein."