NEETZoologyBiotechnology - Principles and Processes
Read the following statements regarding the methods of introducing recombinant DNA into host cells: (A) In micro-injection, recombinant DNA is directly injected into the nucleus of an animal cell. (B) Biolistics or gene gun method uses high-velocity micro-particles of gold or tungsten coated with DNA and is suitable for plant cells. (C) Bacterial cells are made competent to take up DNA by treating them with a specifi
Options
- AOne
- BTwo
- CFour
- DThree
Correct answer
D. Three
Step-by-step solution
Statements (A), (B), and (D) are correct descriptions of gene transfer methods as per NCERT. Statement (C) is incorrect because bacterial cells are made competent by treating them with a specific concentration of a divalent cation, such as calcium, which increases the efficiency with which DNA enters the bacterium through pores in its cell wall. Monovalent cations like sodium are not used for this purpose. Therefore, exactly three statements are correct. Answer: Three