Question 1: Palette 1/63

NEET 2026 MCQ

The correct statement with regard to the secondary structure of DNA/RNA is

A

RNA possesses a single strand helix structure and contains thymine as one of the four bases

B

DNA possesses a double strand helix structure and contains thymine as one of the four bases

C

RNA possesses a double strand helix structure and contains uracil as one of the four bases

D

DNA possesses a single strand helix structure and contains uracil as one of the four bases

Question 2: Palette 2/63

NEET 2026 MCQ

The correct statement about peptides and proteins is

A

In $\alpha$-helices, the polypeptide chain is twisted into a left-handed screw (helix) through intramolecular hydrogen bonds

B

Tertiary structure of proteins has two or more polypeptide subunits

C

Only the proteins having a quaternary structure are biologically active

D

In $\beta$-pleated sheet structures, peptide chains are held together by intermolecular hydrogen bonds

Question 3: Palette 3/63

NEET 2026 MCQ

The amino acid that gives a red-blood colour on treating its sodium fusion extract with sodium nitroprusside is

A

serine

B

leucine

C

threonine

D

methionine

Question 4: Palette 4/63

NEET 2026 MCQ

$ \text { Match the vitamins in List I with their sources in List II } $

$ \begin{array}{|l|l|l|l|} \hline & \text { List I } & & \text { List II } \\ \hline \text { A. } & \text { vitamin A } & \text { I. } & \text { meat } \\ \hline \text { B. } & \text { vitamin B }{ }_{12} & \text { II. } & \text { sunflower oil } \\ \hline \text { C. } & \text { vitamin E } & \text { III. } & \text { green leafy vegetables } \\ \hline \text { D } & \text { vitamin K } & \text { IV. } & \text { carrots } \\ \hline \end{array} $

Choose the correct answer from the options given below.

A

A-III, B-I, C-IV, D-II

B

A-II, B-III, C-IV, D-I

C

A-IV, B-I, C-II, D-III

D

A-IV, B-II, C-I, D-III

Question 5: Palette 5/63

NEET 2025 MCQ

Sugar ' $X$ '

A. is found in honey

B. is a keto sugar

C. exists in $\alpha$ and $\beta$-anomeric forms.

D. Is laevorotatory.

' X ' is :

A

Maltose

B

Sucrose

C

D-Glucose

D

D-Fructose

Question 6: Palette 6/63

NEET 2025 MCQ

Match List-I with List-II.

	List - I (Name of Vitamin)		List - II (Deficiency disease)
A	Vitamin $B_{12}$	I	Cheilosis
B	Vitamin $D$	II	Convulsions
C	Vitamin $B_{2}$	III	Rickets
D	Vitamin $B_{5}$	IV	Pernicious anaemia

Choose the correct answer from the options given below:

A

A-II, B-III, C-I, D-IV

B

A-IV, B-III, C-II, D-I

C

A-I, B-III, C-II, D-IV

D

A-IV, B-III, C-I, D-II

Question 7: Palette 7/63

NEET 2024 MCQ

Given below are two statements :

Statement I : Glycogen is similar to amylose in its structure.

Statement II : Glycogen is found in yeast and fungi also.

In the light of the above statements, choose the correct answer from the options given below :

A

Statement I is true but Statement II is false.

B

Statement I is false but Statement II is true.

C

Both Statement I and Statement II are true.

D

Both Statement I and Statement II are false.

Question 8: Palette 8/63

NEET 2024 MCQ

The reagents with which glucose does not react to give the corresponding tests/products are

A. Tollen's reagent

B. Schiff's reagent

C. HCN

D. $\mathrm{NH}_2 \mathrm{OH}$

E. $\mathrm{NaHSO}_3$

Choose the correct options from the given below:

A

B and C

B

A and D

C

B and E

D

E and D

Question 9: Palette 9/63

NEET 2024 MCQ

Fehling's solution 'A' is

A

aqueous copper sulphate

B

alkaline copper sulphate

C

alkaline solution of sodium potassium tartrate (Rochelle's salt)

D

aqueous sodium citrate

Question 10: Palette 10/63

NEET 2023 MCQ

Given below are two statements:

Statement I : A unit formed by the attachment of a base to 1' position of sugar is known as nucleoside

Statement II : When nucleoside is linked to phosphorous acid at 5' position of sugar moiety, we get nucleotide.

In the light of the above statements, choose the correct answer from the options given below:

A

Both Statement I and Statement II are false

B

Statement I is true but Statement II is false

C

Statement I is false but Statement II is true

D

Both Statement I and Statement II are true

Question 11: Palette 11/63

NEET 2022 MCQ

The incorrect statement about denaturation of proteins is :

A

Uncoiling of the helical structure takes place

B

It results due to change of temperature and/or pH

C

It results in loss of biological activity of proteins

D

A protein is formed from amino acids linked by peptide bonds

Question 12: Palette 12/63

NEET 2022 MCQ

The incorrect statement regarding enzymes is

A

Enzymes are biocatalysts.

B

Like chemical catalysts enzymes reduce the activation energy of bio processes.

C

Enzymes are polysaccharides.

D

Enzymes are very specific for a particular reaction and substrate.

Question 13: Palette 13/63

NEET 2020 MCQ

Which of the following is a basic amino acid?

A

Alanine

B

Tyrosine

C

Lysine

D

Serine

Question 14: Palette 14/63

NEET 2020 MCQ

Sucrose on hydrolysis gives :

A

$\alpha $-D-Glucose + $\beta $-D-Glucose

B

$\alpha $-D-Glucose + $\beta $-D-Fructose

C

$\alpha $-D-Fructose + $\beta $-D-Fructose

D

$\alpha $-D-Glucose + $\alpha $-D-Fructose

Question 15: Palette 15/63

NEET 2019 MCQ

The non-essential amino acid among the following is :

A

alanine

B

lysine

C

valine

D

leucine

Question 16: Palette 16/63

NEET 2018 MCQ

The difference between amylose and amylopectin is

A

amylopectin have 1 $ \to $ 4 $\alpha $-linkage and 1 $ \to $ 6 $\alpha $-linkage

B

amylose have 1 $ \to $ 4 $\alpha $-linkage and 1 $ \to $ 6 $\beta $-linkage

C

amylopectin have 1 $ \to $ 4 $\alpha $-linkage and 1 $ \to $ 6 $\beta $-linkage

D

amylose is made up of glucose and galactose

Question 17: Palette 17/63

NEET 2018 MCQ

Which of the following compounds can form a zwitter ion?

A

Aniline

B

Acetanilide

C

Benzoic acid

D

Glycine

Question 18: Palette 18/63

NEET 2017 MCQ

Which of the following statements is not correct?

A

Ovalbumin is a simple food reserve in egg-white.

B

Blood proteins thrombin and fibrinogen are involved in blood clothing.

C

Denaturation makes the proteins more active.

D

Insulin maintains sugar level in the blood of a human body.

Question 19: Palette 19/63

NEET 2016 MCQ

The correct corresponding order of names of four aldoses with configuration given below

respectively, is

A

L-erythrose, L-threose, L-erythrose, D-threose

B

D-threose, D-erythrose, L-threose, L-erythrose

C

L-erythrose, L-threose, D-erythrose, D-threose

D

D-erythrose, D-threose. L-erythrose, L-threose

Question 20: Palette 20/63

NEET 2016 MCQ

The central dogma of molecular genetics states that the genetic information flows from

A

Amino acids $ \to $ Proteins $ \to $ DNA

B

DNA $ \to $ Carbohydrates $ \to $ Proteins

C

DNA $ \to $ RNA $ \to $ Proteins

D

DNA $ \to $ RNA $ \to $ Carbohydrates

Question 21: Palette 21/63

NEET 2016 MCQ

Which one given below is a non-reducing sugar?

A

Glucose

B

Sucrose

C

Maltose

D

Lactose

Question 22: Palette 22/63

NEET 2016 MCQ

The correct statement regarding RNA and DNA, respectively is

A

The sugar component in RNA is a arabinose and the sugar component in DNA is ribose

B

The sugar component in RNA is 2'-deoxyribose and the sugar component in DNA is arabinose

C

the sugar component in RNA is arabinose and the sugar component in DNA is 2'-deoxyibose

D

the sugar component in RNA is ribose and the sugar component in DNA is 2'-deoxyribose.

Question 23: Palette 23/63

NEET 2016 MCQ

In a protein molecule various amino acids are linked together by

A

peptide bond

B

dative bond

C

$\alpha $-glycosidic bond

D

$\beta $-glycosidic bond.

Question 24: Palette 24/63

NEET 2014 MCQ

D(+)-glucose reacts with hydroxyl amine and yields an oxime. The structure of the oxime would be

A

B

C

D

Question 25: Palette 25/63

NEET 2014 MCQ

Which of the following hormones is produced under the condition of stress which simulate glycogenlysis in the liver of human beings?

A

Thyroxin

B

Insulin

C

Adrenaline

D

Estradiol

Question 26: Palette 26/63

NEET 2013 MCQ

In DNA, the linkages between different nitrogenous bases are

A

phosphate linkage

B

H-bonding

C

glycosidic linkage

D

peptide linkage

Question 27: Palette 27/63

NEET 2012 MCQ

Which one of the following sets of monosaccharides forms sucrose?

A

$\alpha $-$D$-galactopyranose
and $\alpha $-$D$ glucopyranose

B

$\alpha $-$D$-glucopyranose
and $\beta $-$D$ fructofuranose

C

$\beta $-$D$-glucopyranose
and $\alpha $-$D$ fructofuranose

D

$\alpha $-$D$-glucopyranose
and $\beta $-$D$ fructopyranose

Question 28: Palette 28/63

NEET 2012 MCQ

Deficiency of vitamin B₁ causes the disease

A

convulsions

B

beri-beri

C

cheilosis

D

sterility

Question 29: Palette 29/63

NEET 2011 MCQ

Which of the following is not a fat soluble vitamin?

A

Vitamin B complex

B

Vitamin D

C

Vitamin E

D

Vitamin A

Question 30: Palette 30/63

NEET 2011 MCQ

Which of the statements about ''Denaturation'' given below are correct?

(1)  Denaturation of proteins causes loss of secondary and tertiary structures of the protein.
(2)  Denaturation leads to the conversion of double strand of DND into single strand.
(3)  Denaturation affects primary structure which gets distorted.

A

(2) and (3)

B

(1) and (3)

C

(1) and (2)

D

(1), (2) and (3)

Question 31: Palette 31/63

NEET 2011 MCQ

Which one of the following statements is not true regarding (+) lactose?

A

On hydrolysis (+) lactose gives equal amount of D(+) glucose and D(+) galactose.

B

(+) Lactose is a $\beta $-glucoside formed by the union of a molecule of D(+) glucose and a molecule of D(+) galactose.

C

(+) Lactose is a reducing sugar and does not exihibit mutarotation.

D

(+) Lactose, C₁₂H₂₂O₁₁ contains 8-OH groups

Question 32: Palette 32/63

NEET 2010 MCQ

Fructose reduces Tollen's reagent due to

A

asymmetric carbons

B

primary alcoholic group

C

secondary alcoholic group

D

enolisation of fructose followed by conversion to aldehyde by base

Question 33: Palette 33/63

NEET 2010 MCQ

Which one of the following does not exhibit the phenomenon of mutaroation?

A

(+) Sucrose

B

(+) Lactose

C

(+) Maltose

D

($-$) Fructose

Question 34: Palette 34/63

NEET 2009 MCQ

Which of the following hormones contains iodine?

A

Testosterone

B

Adrenaline

C

Thyroxine

D

Insulin

Question 35: Palette 35/63

NEET 2009 MCQ

The segment of DNA which acts as the instrumental manual for the synthesis of the protein is

A

ribose

B

gene

C

nucleoside

D

nucleotide

Question 36: Palette 36/63

NEET 2008 MCQ

Which of the following is an amine hormone?

A

Insulin

B

Progesterone

C

Thyroxine

D

Oxypurin

Question 37: Palette 37/63

NEET 2008 MCQ

In DNA, the complimentary bases are

A

adenine and guanine; thymine and cytosine

B

uracil and adenine; cytosine and guanine

C

adenine and thymine; guanine and cytosine

D

adenine and thymine; guanine and uracil.

Question 38: Palette 38/63

NEET 2007 MCQ

Which of the following vitamins is water-soluble?

A

Vitamin E

B

Vitamin K

C

Vitamin A

D

Vitamin B

Question 39: Palette 39/63

NEET 2007 MCQ

RNA and DNA are chiral molecules, their chirality is due to

A

chiral bases

B

chiral phosphate ester units

C

$D$-sugar component

D

$L$-sugar component

Question 40: Palette 40/63

NEET 2006 MCQ

Which one of the following is a peptide hormone?

A

Adrenaline

B

Glucagon

C

Testosterone

D

Thyroxine

Question 41: Palette 41/63

NEET 2006 MCQ

During the process of digestion, the proteins present in food materials are hydrolysed to amino acids. The two enzymes involved in the process-

are respectively

A

invertase and zymase

B

amylase and maltase

C

diastage and lipase

D

pepsin and trypsin

Question 42: Palette 42/63

NEET 2006 MCQ

The human body does not produce

A

enzymes

B

DNA

C

vitamins

D

hormones

Question 43: Palette 43/63

NEET 2005 MCQ

Which functional group participates in disulphide bond formation in proteins?

A

Thioester

B

Thioether

C

Thiol

D

Thiolactone

Question 44: Palette 44/63

NEET 2005 MCQ

The cell membranes are mainly composed of

A

fats

B

proteins

C

phospholipids

D

carbohydrates

Question 45: Palette 45/63

NEET 2004 MCQ

Which of the following structures represents the peptide chain?

A

B

C

D

Question 46: Palette 46/63

NEET 2004 MCQ

The hormone that helps in the conversion of glucose to glycogen is

A

cortisone

B

bile acids

C

adrenaline

D

insulin

Question 47: Palette 47/63

NEET 2004 MCQ

The helical structure of protein is stablised by

A

dipeptide bonds

B

hydrogen bonds

C

ether bonds

D

peptide bonds

Question 48: Palette 48/63

NEET 2004 MCQ

A sequence of how many nucleotides in messenger RNA makes a codon for an amino acid?

A

Three

B

Four

C

One

D

Two

Question 49: Palette 49/63

NEET 2004 MCQ

Number of chiral carbons in $\beta $-$D$-(+) glucose is

A

five

B

six

C

three

D

four

Question 50: Palette 50/63

NEET 2004 MCQ

The correct statement in respect of protein haemoglobin is that it

A

functions as a catalyst for biological reactions

B

maintains blood sugar level

C

acts as an oxygen carrier in the blood

D

forms antibodies and offers resistance to diseases.

Question 51: Palette 51/63

NEET 2003 MCQ

Vitamin B₁₂ contains

A

Fe (II)

B

Co (III)

C

Zn (II)

D

Ca (II)

Question 52: Palette 52/63

NEET 2003 MCQ

Phospholipids are esters of glycerol with

A

three carboxylic acid residues

B

two carboxylic acid residues and one phosphate group

C

one carboxylic acid residue and two phosphate groups

D

three phosphate groups.

Question 53: Palette 53/63

NEET 2003 MCQ

Chargaff's rule states that in an organism

A

amount of adenine (A) is equal to that of thymine (T) and the amount of guanine (G) is equal to that of cytosine (C)

B

amount of adenine (A) is equal to that of guanine (G) and the amount of thymine (T) is equal to that of cytosine (C)

C

amount of adenine (A) is equal to that of cytosine (C) and the amount of thymine (T) is equal to that of guanine (G)

D

amounts of all bases are equal.

Question 54: Palette 54/63

NEET 2003 MCQ

Glycolysis is

A

oxidation of glucose to glutamate

B

conversion of pyruvate to citrate

C

oxidation of glucose to pyruvate

D

conversion of glucose to haem.

Question 55: Palette 55/63

NEET 2002 MCQ

Enzymes are made up of

A

edible proteins

B

proteins with specific structure

C

nitrogen containing carbohydrates

D

carbohydrates.

Question 56: Palette 56/63

NEET 2002 MCQ

Which is not true statement?

A

$\alpha $-carbon of $\alpha $-amino acid is asymmetric.

B

All proteins are found in $L$-form

C

Human body can synthesise all proteins they need.

D

At pH = 7 both amino and carboxylic groups exist in ionised form.

Question 57: Palette 57/63

NEET 2001 MCQ

Which of the following is correct about H-bonding in nucleotide?

A

A $-$ T, G $-$ C

B

A $-$ G, T $-$ C

C

G $-$ T, A $-$ C

D

A $-$ A, T $-$ T

Question 58: Palette 58/63

NEET 2001 MCQ

Which is the correct statement?

A

Starch is a polymer of $\alpha $-glucose.

B

Amylose is a component of cellulose.

C

Proteins are composed of only one type of amino acid.

D

In cyclic structure of fructose, there are four carbons and one oxygen atom.

Question 59: Palette 59/63

NEET 2001 MCQ

Which statement is incorrect about peptide bond?

A

C $-$ N bond length in proteins is longer than usual bond length of N $-$ C bond.

B

Spectroscopic analysis shows planar structure of group.

C

C $-$ N bond length in proteins is smaller than usual bond length of C $-$ N bond.

D

None of the above.

Question 60: Palette 60/63

NEET 2001 MCQ

Which of the following is correct?

A

Cycloheptane is an aromatic compound.

B

Diastase is an enzyme

C

Acetophenone is an ether.

D

All of these.

Question 61: Palette 61/63

NEET 2000 MCQ

Which one is responsible for production of energy in bio-reaction?

A

Thyroxine

B

Adrenaline

C

Oestrogen

D

Progesterone

Question 62: Palette 62/63

NEET 2000 MCQ

Mg is present in

A

chlorophyll

B

haemoglobin

C

vitamin-D

D

vitamin-B

Question 63: Palette 63/63

NEET 2000 MCQ

$\alpha $ -$D$-glucose and $\beta $-$D$-glucose are

A

epimers

B

anomers

C

enantiomers

D

diastereomers