Nucleic Acids

Q.

What do you mean by recombination?

Q.

When does copying of DNA occur?

Q. Where are nucleic acids found?

1. Viruses only
2. Bacteria only
3. Mammals only
4. All forms of life

Q. Which of the following base pairings is/are possible?

1. Purine-Purine
2. Pyrimidine-Pyrimidine
3. Purine-pyrimidine
4. All of these

Q. How are the two strands of DNA positioned with respect to each other in the double helix?

1. They run parallel to each other.
2. They run antiparallel to each other.
3. They are perpendicular to each other.
4. They intersect each other at an angle.

Q.

Which one of the following is a wrong statement?

1. Anabaena and Nostoc are capable of fixing nitrogen in the free-living state also

2. Root nodule forming nitrogen fixers live as aerobes under free-living conditions

3. Phosphorus is not a constituent of nucleic acids

4. Nitrosomonas and Nitrobacter are chemoautotrophs

Q. How are the two strands of DNA positioned with respect to each other in the double helix?

1. They run parallel to each other.
2. They run antiparallel to each other.
3. They are perpendicular to each other.
4. They intersect each other at an angle.