All Free Biology MCQs with Answers

• A. One sub unit
• B. Two sub units
• C. Three sub units
• D. Four sub units

Explanation: Nucleotide consists of pentose sugar, nitrogenous base and phosphoric acid.

• A. Maurice Wilkins
• B. Erwin Chargaff
• C. Watson and Crick
• D. Rosalind and Franklin

Explanation: Erwin Chargaff was an Austrian-American biochemist. He is best known for his research on the composition of DNA and the discovery of…

• A. Liver
• B. Spleen
• C. W.B.C.
• D. Skin cells

Explanation: The liver is located in the upper right portion of the abdomen, beneath the diaphragm. It is the largest internal organ in the body.

• A. One
• B. Two
• C. Three
• D. No one

Explanation: Dipeptides have only one peptide linkage between them formed by the removal of water

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Amino acids have an amino group (-NH2) and a carboxyl group (-COOH) attached to the same carbon atom, also known as alpha carbon.

• A. Maltose
• B. Glycine
• C. Cellulose
• D. Cellbiose

Explanation: Glycine is an amino acid, which is one of the building blocks of proteins.

• A. α -1-4 linkages
• B. Both α -1-4 and α 1-6 linkages
• C. α -16 linkages
• D. All of the above

Explanation: In amylose, glucose units are linked by α -1-4 linkages.

• A. Glycogen is analogous to starch
• B. It is a structural polysaccharide
• C. It is non reducing sugar
• D. It gives red colour with iodine solution

Explanation: Glycogen is a structural polysaccharide.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Cellulose resembles with amylase starch in such a way that it has un-branched structure, but it has B-1, 4-glycosidic linkages between…

• A. Cellulose
• B. Glycogen
• C. Waxes
• D. Amino acids

Explanation: Cotton is primarily composed of cellulose, a complex carbohydrate or polysaccharide that forms the structural component of plant cell…

• A. Carbon, water, and oxygen
• B. Carbon, sulfur, and hydrogen
• C. Carbon, calcium, and hydrogen
• D. Carbon, hydrogen, and oxygen

Explanation: Carbohydrates are organic molecules composed of three elements: carbon (C), hydrogen (H), and oxygen (O).

• A. F. Sanger
• B. George Beadle
• C. Edward Tatum
• D. Vernon Ingram

Explanation: The correct answer is Ingram. Vernon Ingram's pioneering work in the 1950s showed that sickle cell anaemia is caused by a single amino…

• A. Egg
• B. Fishes
• C. Pulses
• D. Milk

Explanation: The correct answer is C, as pulses are vegetative sources of protein. Pulses, such as beans, lentils, and chickpeas, are especially rich…

• A. Histidine
• B. Lactic acid
• C. Alanine
• D. Glycine

Explanation: The correct answer is lactic acid. Lactic acid is not an amino acid; it is an organic compound that plays a role in various metabolic…

• A. Lipid
• B. Protein
• C. Carbohydrate
• D. Both A and B

Explanation: Sterols, such as cholesterol, are a subgroup of lipids, characterized by their multiple-ring structure.

• A. Insoluble in water and soluble in fat solvents
• B. High energy content
• C. Structural component of the cell membrane
• D. All of these

Explanation: The correct answer is "Option: D: All of these." Lipids are diverse molecules that share several key properties: they are insoluble in…

• A. Ether
• B. Water
• C. Alcohol
• D. All solvents

Explanation: Lipids are primarily nonpolar molecules, which makes them soluble in nonpolar solvents, such as ether.

• A. 2 glycerol, 2 fatty acids & 1 phosphoric acid
• B. 2 glycerol, 1 fatty acids & 1 phosphoric acid
• C. 1 glycerol, 2 fatty acids & 1 phosphoric acid
• D. 2 glycerol, 1 fatty acids & 2 phosphoric acid

Explanation: Phosphatidic acid is a fundamental structure in the formation of phospholipids, which are essential components of cell membranes.

• A. Hydrophilic
• B. Hydrophobic
• C. Neutral
• D. Amphipathic

Explanation: Lipids are insoluble in water because they are hydrophobic. Hydrophobic substances do not interact well with polar water molecules.

• A. Sugarcane
• B. Milk
• C. Almonds
• D. None

Explanation: Sucrose is a disaccharide composed of glucose and fructose. It is most abundantly found in sugarcane and sugar beet, from which it is…