A schematic representation of the steps in Polymerase Chain Reaction (PCR) is shown below. Answer the questions that follow:

(a) Name the steps A and D in the PCR.
(b) Identify B. What are they chemically?
(c) What is C? Name its source organism.

Read the following and answer any four questions from (i) to (v) given below:
Gene manipulation is a fast emerging science. It started with development of recombinant DNA molecule. It is named variously as DNA manipulation biotechnology, recombinant DNA technology and genetic engineering. This technology, that mostly involves cutting and pasting of desired DNA fragments, is based on two important discoveries in bacteria, i.e., presence of plasmid in bacteria and restriction endonucleases. Paul Berg was able to introduce a gene of SV-40 into a bacterium. The science of recombinant DNA technology took birth when Cohen and Boyer (1973) were able to introduce a piece of gene containing foreign DNA into plasmid of E.coli.
(i) Biotechnology is also known as

(ii) A bacterial plasmid is a/an

(iii) Father of genetic engineering is

(iv) Which of the following is used by Paul Berg to introduce a gene of SV-40 in a bacterium?

(v) Read the given statements and select the correct option.
Assertion : Biotechnology started with the development of recombinant DNA molecule.
Reason : Biotechnology mostly involves cutting and pasting of desired DNA fragments.

Read the following and answer any four questions from (i) to (v) given below:
The foundations of recombinant DNA (rDNA) were laid by the discovery of restriction enzymes. These enzymes are present in many bacterias where they function as a part of their defense mechanism called the Restriction Modification system (RM system). Molecular basis of this system was explained first by Werner Arber in 1962. The Restriction t-'l0dification system consists of two components:
1. A restriction enzyme (called restriction endonuclease) identifies the introduced foreign DNA and cuts it into pieces.
2.The second component is a modification enzyme (methylase) that adds a methyl group to DNA at specific site to protect it from the restriction enzyme cleavage.
(i) Restriction endonucleases are enzymes present in (i) where they function as a part of (ii) mechanism.

(ii) Which of the following statements regarding modification enzyme is correct?

(iii) Which of the following is a type II restriction enzyme?

(iv) Which of the following is the first discovered restriction endonuclease?

(v) Components of Restriction Modification System include

Read the following and answer any four questions from (i) to(v) given below:
In recombinant DNA technology, the fragments of DNA generated after cutting the DNA by restriction enzymes are separated according to their size or length by gel electrophoresis. Gel electrophoresis is performed in a gel matrix so that molecules of similar electric charges can be separated on the basis of size. Most commonly used matrix in gel electrophoresis is agarose. The fragments are separated under the influence of electric field. The separated DNA fragments can be seen only after staining the DNA with compound known as ethidium bromide (EtBr) followed by exposure to UV radiation as bright orange band.
(i) Gel electrophoresis is used for the separation of

(ii) Most commonly used matrix is (i) which is a (ii) extracted from (iii).

(iii) A DNA molecule was treated with a restriction endonuclease and three fragments of size (i) 426 kb, (ii) 129 kb and (iii) 46 kb were obtained. Identify the order in which these bands will arrange themselves in the gel plate after gel electrophoresis is completed. (Assuming that negative part of electrode is towards the well)

(iv) Which of the following statements regarding gel electrophoresis is incorrect?

(v) The factor that will not affect the rate of DNA migration in gel electrophoresis is

Read the following and answer any four questions from (i) to (v) given below:
The DNA, which is transferred from one organism into another by joining it with the vehicle DNA is called passenger or foreign DNA. Generally three types of passenger DNAs are used. These are complementary DNA (cDNA), synthetic DNA (sDNA) and random DNA. Complementary DNA (cDNA) is synthesized on RNA template (usually mRNA) with the help of reverse transcriptase. Synthetic DNA (sDNA) is synthesized on DNA template or without a template. Random DNA are small fragments formed by breaking a chromosome of an organism in the p.resence of restriction endonucleases.

(i) Reverse transcriptase enzyme was discovered by

(ii) During cDNA formation, what would happen if DNA formed by reverse transcriptase is not treated with the alkali?

(iii) Enzyme that helps in the formation of double stranded cDNA is

(iv) DNA polymerase can be obtained form

(v) DNA synthesised without a template is referred to as