Which of the following is considered as physical and chemical unit of heredity?
Correct answer: (a)
Solution: A gene is a locus (or region) of DNA which is made up of nucleotides and is the molecular unit of heredity. It controls the development and function of all organs and all working systems in the body. Genes are passed from parent to offspring; the combination of these genes affects all aspects of the human body, from eye and hair colour to how well the liver can process toxins.