Question

Read the following statements:

(i) Primers used in PCR are small chemically synthesized oligosaccharides
(ii) E. coli is closely related to Salmonella
(iii) There are 3 basic steps in genetically modifying an organism
(iv) The techniques of the genetic engineering overcome the limitation of traditional hybridisation procedures

In these statements how many are correct?

• A. 4
• B. 3
• C. 1
• D. 2

Answer 1

The correct option is A 4

i, ii, iii and iv all are correct statements.
Primers used in PCR are small chemically synthesized oligonucleotides.
E.coli is closely related to Salmonella as both are the bacteria and they live inside the intestine of humans. Salmonella is evolved from E.coli millions of years ago.
There are three basic steps in genetically modifying an organism :
(i) Identification of DNA with desirable genes.
(ii) Introduction of the identified DNA into the host.
(iii) Maintenance of introduced DNA in the host and transfer of the DNA to its progeny.
Genetic engineering can overcome all these drawbacks because use of recombinant DNA technology, gene cloning and gene transfer allow us to isolate and introduce only desirable genes.

Therefore, all the given statements are correct.