The number of cyclic rings present in purines and pyrimidines are

1. 2,1 respectively

2. 1,2 respectively

3. 2,2 respectively

4. 1,1 respectively

The amino acids which are synthesised by our body are known as

1.Essential amino acids

2.Non-essential amino acids

3.optical amino acids

4.Both 1 and 3

The body meets the demand of essential amino acids through

1.Food

2.body synthesised  on its own

3.Both A and B

4.None of these

Which of the following is not the function of protein

1.Act as hormones

2.act as enzymes

3.act as genetic material

4.fight against infections

In proteins, amino acids are linked by  a type of

1.Acetyl bond

2.Amide bond

3.Ester bond

4.Glycosidic bond

The formation of amide bond shows which type of reaction

1.Substitution reaction

2.Elimination reaction

3.Addition reaction

4.Rearrangement reaction

In polysaccharides the individual monosaccharides are linked by

1.Phosphodiester bond

2.Amide bond

3.Ester bond

4.Glycosidic bond

The DNA exists as _________helix which runs ________

1.double, parallel

2.double, antiparallel

3.single, perpendicular

4.single, parallel

Both the strands of the DNA are joined by

1.Disulphide bond

2.Hydrogen bonds

3.Glycosidic bonds

4.phosphodiester bonds

Which of the following is the pitch of B-DNA

1.34Angstrom

2.34 nanometre

3.34 picometre

4.34 femtometre