Question

Assertion: Eukaryotic genome is classified into highly repetitive, moderately repetitive, and single-copy DNA on the basis of reiteration.
Reason: Reassociation kinetics of repetitive DNA is slower than the non-repetitive DNA.

• A. Both the assertion and reason are true and the reason is the correct explanation of the assertion
• B. Both assertion and reason are true but the reason is not the correct explanation of the assertion
• C. Assertion is true but the reason is false
  
• D. Both the assertion and the reason are false
  

Answer 1

The correct option is C Assertion is true but the reason is false


On the basis of reiteration frequency genome is classified into highly repetitive, moderately repetitive, and single/low copy DNA.

Non-repetitive DNA
Those sequences which are present in only one copy number in the haploid genome. Coding sequences are examples of non-repetitive DNA

Repetitive DNA
Those sequences that are present in more than one copy number in the haploid genome. They are of two types:
1. Moderately repetitive DNA:
These are short sequences that are repeated 10-1000 times in the genome. They generally dispersed throughout the genome.
2. Highly repetitive DNA:
These are very short DNA sequences(<100bp) which are organised as long tandem repeats.

The reassociation kinetics of repetitive DNA is faster than the non-repetitive DNA because the complementary sequence of the repetitive DNA is more in the genome as compared to non-repetitive DNA. Thus, repetitive DNA easily finds a complementary sequence as compared to non-repetitive DNA.