DNA replication generally proceeds in a 

• 5 $\to$3 direction

• 3 $\to$5 direction

• 3 $\to$3 direction

• 5 $\to$5 direction

DNA polymerase enzyme is required for synthesis of

• DNA from RNA

• RNA from DNA

• DNA from DNA

• RNA from RNA

Which type of DNA is found in bacteria

• Helical DNA

• Membrane bound DNA

• Straight DNA

• Circular free DNA

The chemical knifes of DNA are

• polymerases

• ligases

• endonucleases

• amylases

Refer to the given figure and select the correct option regarding its parts labelled as A, B and C.

• A-Histone octamer, C-DNA

• B-H₁ histone, C-Histone octamer

• A-H₁ histone, B-DNA

• A-Histone octamer, C-H₁ histone

Match the triplet codons listed in column I with their amino acids mentioned in column II and select the correct option from the given codes.
          Column I             Column II
        A. GGG                    (i) Proline
        B. UUU                    (ii) Glycine
        C. CCC                    (iii) Arginine
        D. AAA                    (iv) Phenylalanine
                                      (v) Lysine

• A-(v), B-(iii), C-(i), D-(ii)

• A-(v), B-(iii), C-(i), D-(iv)

• A-(ii), B-(iv), C-(i), D-(v)

• A-(i), B-(ii), C-(iii),D-(iv)

Radio-tracer technique shows that DNA is in

• single-helix stage

• double-helix stage

• multi-helix stage

• none of these

Assertion: The honeybee queen copulates only once in her life time.

Reason: The honeybee queen can lay fertilised as well as unfertilised eggs.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

309.

In a 3.2 Kbp long piece of DNA, 820 adenine bases were found. What would be the number of cytosine bases?

• 780

• 1560

• 740

• 1480

Some of the steps of DNA fingerprinting are given below. Identify their correct sequence from the options given.

A. Electrophoresis of DNA fragments
B. Hybridisation with DNA probe
C. Digestion of DNA by restriction endonucleases
D. Autoradiography
E. Blotting of DNA fragmentsto nitrocellulose membrane

• C - A - B - E - D

• C - A - E - B - D

• A - E - C - B - D

• A - C - E - D - B