Question

Which bacteria is called the DNA repair champion

• A. Deinococcus radiodurans
• B. Escherichia coli
• C. Bacillus brevis
• D. Streptomyces sp

Hint:

The name "radiodurans" is a clue: it combines "radio" (for radiation) and "durans" (from the Latin for durable or enduring). This bacterium is literally "radiation-enduring."

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The title "DNA repair champion" is given to the bacterium that exhibits the most extraordinary ability to withstand DNA damage, particularly from ionizing radiation, and then efficiently repair that damage.
Step 2: Detailed Explanation:
1. Deinococcus radiodurans: This bacterium is an extremophile, famously listed in the Guinness Book of World Records as "the world's toughest bacterium." It can survive cold, dehydration, vacuum, acid, and, most notably, radiation doses about 3,000 times greater than those that would kill a human. Its extreme radiation resistance is due to a highly efficient set of DNA repair mechanisms and the presence of multiple copies of its genome, which it uses as templates for repair. This makes it the undisputed "DNA repair champion."
2. Escherichia coli: This is a standard model organism in microbiology and has robust DNA repair systems, but they are not nearly as effective as those of *D. radiodurans*.
3. Bacillus brevis: This bacterium is known for producing antibiotics like gramicidin, but not for exceptional DNA repair.
4. Streptomyces sp: This genus of bacteria is a prolific source of antibiotics but is not specifically known for being a DNA repair champion.
Step 3: Final Answer:
*Deinococcus radiodurans* is renowned for its unparalleled ability to repair extensive DNA damage, earning it the nickname "Conan the Bacterium" and the title of DNA repair champion.