Which of the following is the site of protein synthesis?
Nucleus
Ribosome
Mitochondria
Endoplasmic reticulum
Ribosomes are the site of protein synthesis in cells. They are small, complex structures composed of RNA and protein that bind to mRNA and use it as a template to synthesize proteins. Hence option 2 is the correct answer.
Option(1) Nucleus is the hereditary centre and it is not the site of protein synthesis. Hence option 1 is incorrect.
Option(3) Mitochondria is the power house of the cell and it is not the site of protein synthesis. Hence option 3 is incorrect.
Option(4) Smooth endoplamic reticulum is concerned with lipid synthesis and rough lodges ribosomes in which protein synthesis occurs and it is not directly involved in protein synthesis. Hence option 4 is incorrect.