1631. Melting temperature of DNA is increased by :

A. A and T content
B. G and C content *
C. Sugar content
D. Phosphate content

1632. The four nitrogen atoms for the de novo synthesis of purine nucleus are provided by :

A. Aspartate, Aspartate, Glutamine and Glycine
B. Aspartate, Aspartate, Glutamine and Glycine
C. Aspartate, Aspartate, Glutamine and Glycine
D. Aspartate, Glutamine, Glutamine and Glycine *

1633. Which of the following is the most likely mechanism fo sickle cell anaemia mutation ?

A. Crossing over
B. Tow base insertion
C. Single base insertion
D. Single base subsititution *

1634. Alopurinol is competitive inhibitor of :

A. Xanthine oxidase *
B. Para Amino benzoic acid (PABA)
C. Folic acid
D. None of these

1635. Which one of the following is initiating condon ?

A. AUG *

1636. Alopurinol inhibits uric acid formation by inhibiting the enzyme :

A. Adenosine deaminase
B. Purine nucleotide phosphorylase
C. Guanase
D. Xanthine oxidase *

1637. The number of condons for serine is :

A. One
B. Two
C. Three
D. Six *

1638. Direction of DNA synthesis is :

A. 5′-3′ direction *
B. 3′-s’ direction
C. 5′-2′ direction
D. None of the above

1639. The number of termination condons is :

A. 1
B. 2
C. 3 *
D. 4

1640. Synthesis of RNA from DNA template is known as :

A. Replication
B. Translation
C. Transcription
D. Mutation