Question

The colonies of recombination bacteria appear white in contrast to the blue colonies of non-recombinant bacteria because of?

• A. inactivation of glycosidase enzyme in recombinant bacteria
• B. insertional inactivation of alpha galactosidase in recombinant bacteria
• C. insertional inactivation of alpha galactosidase in non-recombinant bacteria
• D. non-recombinant bacteria containing beta galactosidase

Answer 1

The correct option is B

insertional inactivation of alpha galactosidase in recombinant bacteria

The correct option is B

Explanation of the correct option:

1. Recombinant bacteria are detected in cloning experiments using blue-white screening.
2. α-complementation plays a role in determining whether the bacteria is recombinant or not.
3. In case of normal cells, β-galactosidase is active, thus forming blue colonies.
4. In case of recombinant cells, α-complementation does not occur, thus producing no blue colour.
5. Hence, due to the insertional inactivation of alphagalactosidase in recombinant bacteria, the colonies of recombinant bacteria appear white in comparison to the blue colonies of non-recombinant bacteria.

Final answer: The colonies of recombination bacteria appear white in contrast to the blue colonies of non-recombinant bacteria because of insertional inactivation of alpha galactosidase in recombinant bacteria.