All Free Biology MCQs with Answers

• A. Fats /cholestrol
• B. ATP
• C. Not known without screening test
• D. Ligase

Explanation: Ligase happens to be an enzyme, catalysing lipids. Since enzymes are proteins, ligase is also a protein.

• A. Acid
• B. Base
• C. Neutral
• D. None of these

Explanation: The following question requires the candidate to have the basic knowledge of the structue of amino acid and it's behavior in…

• A. 25
• B. 20
• C. 19
• D. 15

Explanation: "About 170 types of amino acids have been found to occur in cells and tissues. Of these, about 25 are constituents of proteins.

• A. Primary structure
• B. Tertiary structure
• C. Secondary structure
• D. Quaternary structure

Explanation: The tertiary structure is the overall folding of the polypeptide chain, and it is determined by the interactions between the side chains…

• A. C-N link
• B. C-O link
• C. N-H link
• D. C-H link

Explanation: Correct option A. Since peptide bond is an amide type of covalent chemical bonding formed between the alpha nitrogen of one amino acid and…

• A. 575
• B. 576
• C. 574
• D. 573

Explanation: Correct option: C (fact) (There are 574 amino acids in a haemoglobin molecule).A haemoglobin molecule consists of a total of 574 amino…

• A. Globular
• B. Functional
• C. Fibrous
• D. Both Options A and B are correct

Explanation: Antibodies belong to a group of globular proteins in serum or plasma; they are therefore also known as immunoglobulins.

• A. 250
• B. 200
• C. 20
• D. 170

Explanation: The total number of amino acids that have been found in tissues and cells are 170. 20 types of amino acids make proteins.

• A. Skin
• B. Hair
• C. Nails
• D. Body fat

Explanation: Proteins are not typically present in body fat. Body fat, also known as adipose tissue, is primarily made up of adipocytes (fat cells)…

• A. Acid
• B. Base
• C. Neutral
• D. None of these options are correct

Explanation: Correct option is B. Based on the definition of the acidic medium, in acidic conditions the amino acid acts as a base and accepts a proton…

• A. 1
• B. 3
• C. 2
• D. 4

Explanation: Insulin is a protein made up of two polypeptide chains referred to as the A chain and the B chain.

• A. A protein
• B. Globular protein
• C. Functional protein
• D. Secretive protein

Explanation: If amino acids are formed together by peptide bonds, they form proteins. Amino acids are the building blocks of protein.

• A. Primary structure
• B. Secondary structure
• C. Tertiary structure
• D. Quarternary structure

Explanation: The linear sequence of amino acids within a protein is considered the primary structure of the protein.

• A. Primary structure
• B. Secondary structure
• C. Tertiary structure
• D. Quaternary structure

Explanation: A protein molecule is made up of many amino acid molecules which are attached by peptide bonds.

• A. Thermoreceptor
• B. Photoreceptor
• C. Chemoreceptor
• D. Nocireceptor

Explanation: The pain receptors are nociceptors. They are known to exist in muscle, joints, and skin.

• A. Paccinian's corpuscles
• B. Olfactory receptors
• C. Miessner's corpuscles
• D. Nociceptors

Explanation: Meissner corpuscles consist of a cutaneous nerve ending responsible for transmitting the sensations of fine, discriminative touch and…

• A. Vision
• B. Metabolism
• C. Muscle contraction
• D. Muscle twitch

Explanation: The retina is a thin layer of tissue that lines the back of the eye on the inside. It is located near the optic nerve.

• A. Monosynaptic reflex arc
• B. Disynaptic reflex arc
• C. Polysynaptic reflex arc
• D. Asynaptic reflex arc

Explanation: Monosynaptic reflex arc has only two neurons, i.e. sensory and motor which form one synapse.

• A. Reflex arc
• B. Sensory pathway
• C. Motor pathway
• D. Somatosensory pathway

Explanation: A reflex, is an involuntary and nearly instantaneous movement in response to a stimulus.A reflex arc is a neural pathway that controls a…

• A. Loss of tail of developing humans embryos
• B. Loss of tissues between developing digits
• C. Controlling the number of neurons
• D. None of the these

Explanation: All of the options listed are related to apoptosis, which is a programmed cell death process essential for the development, tissue…