What are tandem repeats in the human genome?

What are tandem repeats in the human genome?

• A. Regions that never mutate.
• B. Random scattered single nucleotides.
• C. Sequences of letters that are repeated numerous times, which help distinguish one DNA type from another.
• D. Segments that code for repetitive proteins.

Answer: (C)

Tandem repeats are a sequence of nucleotides that is copied in a row, one after another, in the genome. The number of times that short sequence repeats can vary greatly from person to person. That variability at multiple repeat sites creates a distinctive pattern for each individual, which is why these repeats are so powerful for DNA profiling and identifying samples. This describes the correct concept because it captures both the repetitive structure and the crucial point that the copy number differs among individuals, providing the basis for distinguishing DNA samples. Other ideas miss the key feature: some regions do mutate and change in repeat count, random single nucleotides describe SNPs rather than tandem repeats, and while repeats can occur in coding regions, the primary usefulness here lies in the variable repeating copies used for identification, not in coding for repetitive proteins.

Tandem repeats are a sequence of nucleotides that is copied in a row, one after another, in the genome. The number of times that short sequence repeats can vary greatly from person to person. That variability at multiple repeat sites creates a distinctive pattern for each individual, which is why these repeats are so powerful for DNA profiling and identifying samples.

This describes the correct concept because it captures both the repetitive structure and the crucial point that the copy number differs among individuals, providing the basis for distinguishing DNA samples. Other ideas miss the key feature: some regions do mutate and change in repeat count, random single nucleotides describe SNPs rather than tandem repeats, and while repeats can occur in coding regions, the primary usefulness here lies in the variable repeating copies used for identification, not in coding for repetitive proteins.