How many types of nitrogenous bases are present in nucleic acid

1. 4
2. 3
3. 5
4. 6

How many of the following are purines?

Adenine, Uracil, Cytosine, thymine, Cysteine, threonine, Tryptophan, Guanine, Thymine

(1)5

(2)4

(3)2

(4)3

How many of the following are pyrimidines?

Adenine, Uracil, Cytosine, Cysteine, threonine, Trytophan, Guanine, Thymine

1. 5

2. 4

3. 2

4. 3

Which of the following is true about sugar of RNA

(1)Ribose sugar is present

(2)2’deoxyribose sugar is present

(3)5C sugar is present

(4)All is true except (B)

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 bond between the phosphate and hydroxyl group of sugar  is an

(1)ether bond

(2)ester bond

(3)glycosidic bond

(4)amide bond

How many phosphodiester bonds are present in 5’ATTTTTGG 3’ sequence of nucleotides

1. 7
2. 9
3. 8
4. 6

The DNA exists as _________helix which runs ________

(1)double, parallel

(2)double, antiparallel

(3)single, perpendicular

(4)single, parallel

The backbone of the DNA is formed by

In DNA strands, there are ____ H- bonds b/w A and T and ____H-bonds b/w G and C respectivley

(1)2,3

(2)3,2

(3)2,2

(4)3,3