| 1. | DNA contains thymine and ribose, RNA contains uracil and deoxyribose. |
| 2. | DNA contains uracil and ribose, RNA contains thymine and deoxyribose. |
| 3. | DNA contains uracil and deoxyribose, RNA contains thymine and ribose. |
| 4. | DNA contains thymine and deoxyribose, RNA contains uracil and ribose. |
Adenine and guanine are:
1. Substituted purines
2. Substituted pyrimidines
3. Deoxyribonucleosides
4. Ribonucleotides
| Assertion(A): | The B-DNA form of the double helix has a pitch of 36Å and each turn consists of TWELVE base pairs. |
| Reason(R): | At each step of ascent, the strand turns 34°. |
| 1. | Both (A) and (R) are True and (R) correctly explains (A) |
| 2. | Both (A) and (R) are True but (R) does not correctly explain (A) |
| 3. | (A) is True but (R) is False |
| 4. | Both (A) and (R) are False |
| 1. | Nitrogen bases such as adenine, guanine, cytosine, uracil, and thymine contain heterocyclic rings. |
| 2. | When a nitrogen base is attached to a sugar molecule, the compound formed is called a nucleoside. |
| 3. | Nucleotides are formed when a nitrogen base is directly esterified to a phosphate group without sugar involvement. |
| 4. | DNA and RNA are nucleic acids, composed exclusively of nucleotides, and can function as genetic material. |
| Assertion(A): | In the Watson-Crick model of DNA, adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C). |
| Reason(R): | Adenine and thymine form three hydrogen bonds, while guanine and cytosine form two hydrogen bonds. |
| 1. | Both (A) and (R) are True and (R) correctly explains (A) |
| 2. | Both (A) and (R) are True but (R) does not correctly explain (A) |
| 3. | (A) is True but (R) is False |
| 4. | Both (A) and (R) are False |
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
| 1. | 3’-carbon of one sugar of one nucleotide to the 5’-carbon of the sugar of the succeeding nucleotide. |
| 2. | 5’-carbon of one sugar of one nucleotide to the 1’-carbon of the sugar of the succeeding nucleotide. |
| 3. | 3’-carbon of one sugar of one nucleotide to the 2’-carbon of the sugar of the succeeding nucleotide. |
| 4. | 2’-carbon of one sugar of one nucleotide to the 5’-carbon of the sugar of the succeeding nucleotide. |
Adenosine, Guanosine, thymidine, uridine, cytidine are all ________ but adenylic acid, guanylic acid, uridylic acid, cytidylic acid are ______:
| 1. | Nucleotides, nucleosides |
| 2. | Nucleosides, nucleotides |
| 3. | Nucleotides, nucleic acids |
| 4. | Nucleotides, nucleases |