Question

Repetitive DNA in humans shows

• A. Low degree of polymorphism
• B. Moderate polymorphism
• C. High degree of polymorphism
• D. No polymorphism

Answer 1

The correct option is C High degree of polymorphism

Repetitive DNA
These are sequences that are present in more than one copy number in the haploid genome. Naturally these sequences are non-coding by nature. Thus mutations in these sequences are carried forward and have very little immediate effect.

They are of two types -
Moderately repetitive DNA: These are short sequences that are repeated 10-1000 times in the genome. They are generally dispersed throughout the genome.

Highly repetitive DNA: These are very short DNA sequences(<100bp) which are organised as long tandem repeats.

These repetitive sequences show a high degree of polymorphism and they are inherited. DNA polymorphisms are the different DNA sequences among individuals, groups, or populations. Polymorphism at the DNA level includes a wide range of variations from single base pair change, many base pairs, and repeated sequences. Polymorphisms can also be much larger in size and involve long stretches of DNA.