All Free Biology MCQs with Answers

• A. two RNAs
• B. a single R.N.A
• C. D.N.A and R.N.A
• D. D.N.A

Explanation: HIV contains two identical RNAs enclosed within capsid

• A. One million
• B. Two million
• C. Three million
• D. Five million

Explanation: AIDS is a major global health concern, with mortality rates exceeding three million per year worldwide.

• A. gag, pol, rev
• B. gag, pol, vpu
• C. gag, pol, vpr
• D. gag, pol, env

Explanation: Students should learn that gag, pol, env are the 3 non-infective genes of HIV

• A. TD4
• B. T4
• C. C4
• D. CD4

Explanation: HIV (Human Immunodeficiency Virus) primarily targets and infects CD4-positive T cells, which are crucial for coordinating the immune…

• A. gp120
• B. gp 11
• C. p17
• D. Both a and b

Explanation: also known as the matrix protein (MA), forms the matrix of the HIV virus, which surrounds the viral core.

• A. Primary wall _ secondary wall _ middle lamella
• B. Secondary wall _ primary wall _ middle lamella
• C. Primary wall _ middle lamella _ secondary wall
• D. Secondary wall _ middle lamella _ primary wall

Explanation: The correct arrangement of cell wall layers in a plant cell is Secondary wall _ Primary wall _ Middle lamella.

• A. Proteins
• B. Lipids
• C. Lipo protein
• D. Cellulose

Explanation: Lipids → mainly phospholipids, form the bilayer (structural framework).Proteins → embedded or attached, responsible for transport…

• A. Cellulose
• B. pectin
• C. Lignin
• D. Murein

Explanation: The middle lamella is made up of pectin in the form of calcium and magnesium pectates.

• A. Matthias Schleiden
• B. Theodor Schwann
• C. Robert Hooke
• D. Robert Brown

Explanation: The cell theory, a fundamental principle in biology, was proposed by Matthias Schleiden and Theodor Schwann.

• A. Hair
• B. Skin
• C. Bone
• D. Muscle

Explanation: Keratinized epithelium is a stratified squamous epithelium (consisting of flattened squamous cells arranged in layers upon the basal…

• A. Primary cell wall
• B. Secondary cell wall
• C. Middle lamella
• D. Plasma membrane

Explanation: Cellulose is a crucial polysaccharide that forms the structural component of the primary cell wall in plants.

• A. Waldyne
• B. T.H. Margan
• C. Robert Brown
• D. Kohler

Explanation: The correct answer is Robert Brown, who discovered the cell nucleus in 1831 while examining plant cells under a microscope.

• A. Catalase
• B. Lipase
• C. Permease
• D. Arginase

Explanation: The correct answer is Permease, which is a protein carrier in the plasma membrane.

• A. Membrane proteins
• B. Membrane carbohydrates
• C. Membrane glycolipids
• D. Membrane cholesterol

Explanation: Membrane proteins regulate the selective permeability of the plasma membrane, allowing the movement of molecules according to the needs of…

• A. Lupus
• B. Scleroderma
• C. Ankylosing spondylitis
• D. Juvenile dermatomyositis

Explanation: An autoimmune disorder in which stiffness and inflammation of vertebrae occur is called Ankylosis spondylitis.

• A. Quina quina
• B. Lathyrus plant
• C. Calotropis plant
• D. Cinchona plant

Explanation: Fact. Quinine is an alkaloid derived from the bark of the South American cinchona tree.

• A. 100°C
• B. 100°C for 30 min
• C. 71°C for 15 min and 62°C for 32 min
• D. 71°C for 32 min and 62°C for 15 sec

Explanation: Pasteurization is a food processing method where a mild heat treatment is applied to food to kill harmful bacteria (pathogens) and extend…

• A. Parents who gestated and gave birth to Dolly
• B. Parents, who donated egg cell
• C. Parent, who donated somatic cell
• D. Both b and c

Explanation: The correct answer is Option D: Both b and c. Dolly, the cloned sheep, was identical to the sheep whose somatic cell was used for cloning…

• A. 8
• B. 12
• C. 16
• D. 20

Explanation: Primers in PCR are typically designed to be 18-22 bases long. This length allows them to bind specifically to the target DNA sequence…

• A. Gave birth to the dolly
• B. Donated reproductive cells
• C. Donated somatic cell
• D. Both A and B

Explanation: Dolly, the cloned baby sheep, was created using a somatic cell nuclear transfer (SCNT) technique.