AIIMS 2005 Zoology Gene Cloning Assertion Reason Question

Explanation of the Question

Assertion: In recombinant DNA technology, human genes are often transferred into bacteria (prokaryotes) or yeast (eukaryotes).

Reason: Both bacteria and yeast multiply very fast to form huge populations which express the desired gene.

Correct Answer: A

Why the Correct Answer is Right

1. Validity of the Assertion:

   • The assertion is true because recombinant DNA technology involves the insertion of human genes into suitable host organisms to produce proteins or other products that can be beneficial for medical and industrial purposes. Bacteria like Escherichia coli and yeast like Saccharomyces cerevisiae are commonly used as hosts due to their well-characterized genetics and ability to be manipulated easily.

2. Validity of the Reason:

   • The reason provided is also true. Both bacteria and yeast have rapid growth rates, which allow them to rapidly increase in population. This characteristic is crucial in recombinant DNA technology as it enables the quick production of the desired gene product in large quantities. The expression of the inserted gene can occur simultaneously as the host cells proliferate, leading to efficient production.

3. Relationship Between Assertion and Reason:

   • The reason correctly explains the assertion. The ability of bacteria and yeast to multiply quickly is a key factor that makes them suitable hosts for gene transfer in recombinant DNA technology. Thus, both statements are true, and the reason justifies the assertion.

Why Other Options are Incorrect

• Option B: If both Assertion & Reason are true but the reason is not the correct explanation of the assertion.

  • This option is incorrect because the reason does provide a valid explanation for why human genes are transferred into these organisms: their rapid multiplication allows for efficient gene expression.

• Option C: If Assertion is true but Reason is false.

  • This option is incorrect because both the assertion and reason are true. The reason is not false; it accurately describes a significant aspect of recombinant DNA technology.

• Option D: If both Assertion and Reason are false statements.

  • This option is incorrect as well since both the assertion and reason are true.

Summary

In summary, both the assertion and the reason are true, with the reason correctly explaining the assertion. Thus, the answer is A. Understanding the rapid growth rates of bacteria and yeast is essential in grasping the principles of recombinant DNA technology and its applications in biotechnology.