What Characteristic of Short Tandem Repeats (STRs)makes Them Useful for DNA

Question

What characteristic of short tandem repeats (STRs)makes them useful for DNA fingerprinting?
A)The number of repeats varies widely from person to person or animal to animal.
B)The sequence of DNA that is repeated varies significantly from individual to individual.
C)The sequence variation is acted upon differently by natural selection in different environments.
D)Every racial and ethnic group has inherited different short tandem repeats.
E)Each STR can be correlated with a specific disease.

Accepted Answer

Short tandem repeats (STRs) are characterized by variable numbers of repeating units (usually 2 to 6 base pairs long) that occur in non-coding regions of the genome. The number of repeats varies widely among individuals, making them useful for DNA fingerprinting. This variability is due to the fact that STRs are highly polymorphic, meaning they exhibit high levels of genetic variation within and between populations. By comparing the number of repeats at specific STR loci between two or more DNA samples, it is possible to distinguish between individuals and assess their genetic relatedness.