The structural and functional unit of heredity is the: MCQ with Answer and Explanation

The structural and functional unit of heredity is the:
A. DNA
B. Gene
C. Chromosome
D. Nucleotide
Answer: Option B
Solution (By JKExamLibrary)
A gene is a segment of DNA that codes for a functional product (protein or RNA) and is the basic unit of heredity. It determines traits. Chromosomes are structures containing many genes. DNA is the genetic material, and nucleotides are the building blocks. Genes are passed from parents to offspring.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Biology Questions

Question #1
Which of the following is an antibiotic produced by a bacterium?
A. Cephalosporin
B. Streptomycin
C. Penicillin
D. Griseofulvin

Correct Answer: Option B


Explanation:
Streptomycin is an antibiotic produced by the bacterium Streptomyces griseus. Penicillin and cephalosporins are from fungi (Penicillium and Cephalosporium). Griseofulvin is a fungal antibiotic. Streptomycin is a broad-spectrum aminoglycoside, effective against gram-negative bacteria and Mycobacterium tuberculosis. It inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit.

This question belongs to: Science Biology
Question #2
Consider statements about human nutrition: 1. Carbohydrates provide energy. 2. Proteins build and repair tissues. 3. Fats are harmful and should be avoided. Which are correct?
A. 1, 2 and 3
B. 1 and 3 only
C. 2 and 3 only
D. 1 and 2 only

Correct Answer: Option D


Explanation:
Carbohydrates are the body's primary and most efficient source of energy, broken down into glucose to fuel cellular activities and physical exertion. Proteins are essential macronutrients composed of amino acids, crucial for the growth, maintenance, and repair of body tissues, as well as forming enzymes, hormones, and antibodies. Fats are essential macronutrients; they provide concentrated energy, are vital for cell membrane structure, aid in the absorption of fat-soluble vitamins, and provide essential fatty acids. They should not be entirely avoided. Thus, statements 1 and 2 are correct.

This question belongs to: Science Biology
Question #3
Which hormone is responsible for lowering blood glucose levels by promoting cellular uptake of glucose?
A. Thyroxine
B. Insulin
C. Cortisol
D. Glucagon

Correct Answer: Option B


Explanation:
Insulin is a peptide hormone secreted by the beta cells of the Islets of Langerhans in the pancreas. Its primary function is to lower blood glucose levels (hypoglycemic effect) by promoting the cellular uptake of glucose, particularly in muscle and fat cells, and its conversion to glycogen (glycogenesis) in the liver. Glucagon has the opposite effect.

This question belongs to: Science Biology