Soru

Zorluk: OrtaExplicit Details

The bacterium *Deinococcus radiodurans* is renowned for its ability to survive extreme doses of ionizing radiation that would be lethal to most other organisms. While radiation shatters the bacterium’s chromosome into hundreds of fragments, *D. radiodurans* can assemble these pieces back into a functional genome within hours. Researchers have determined that this rapid repair is facilitated by the bacterium's ring-like nucleoid structure, which keeps the damaged DNA fragments in close spatial alignment. This structural arrangement prevents the fragments from diffusing away from one another, allowing repair proteins to efficiently rejoin the correct segments in their original order.

According to the text, how does the structure of *Deinococcus radiodurans* support its genome repair process?

  1. A
    By preventing the chromosome from breaking into fragments when exposed to radiation.
  2. B
    By allowing the bacterium to mutate its genes to survive in radioactive environments.
  3. By keeping the broken DNA fragments close together to prevent them from dispersing.Cevap
  4. D
    By producing repair proteins that absorb and neutralize ionizing radiation.

Cevap

By keeping the broken DNA fragments close together to prevent them from dispersing.
The text explicitly states that the bacterium's ring-like nucleoid structure keeps the damaged DNA fragments in close spatial alignment, which prevents them from diffusing (dispersing) away from one another, allowing repair proteins to rejoin them.

Adım Adım Çözüm

1
Locate the portion of the text that describes the structure of the bacterium and how it relates to genome repair.
The text states that the rapid repair is facilitated by the bacterium's ring-like nucleoid structure, which keeps the damaged DNA fragments in close spatial alignment.
This step identifies the exact physical mechanism mentioned in the passage.
2
Determine the explicit effect of this structural arrangement.
The text states that this arrangement prevents the fragments from diffusing away from one another, allowing repair proteins to rejoin them.
This matches the explanation that the structure keeps the fragments close together to prevent them from dispersing.

Anahtar Kavram

Explicit Details
Bu soruyu puanla