Quantitative trait locus

Quantitative trait locus (QTL) is like a map that helps us find the genes responsible for certain traits. Let's imagine we want to know why some people have curly hair and some have straight hair. We can look at their genes and try to see which parts are responsible for the trait, but genes are really complex and it's hard to know which parts do what.

That's where the QTL comes in. Scientists can study many people who have different hair types and look for patterns in their genes. They can then use a computer to find where those patterns are coming from (it's like the computer is drawing a map to show where the genes that cause curly or straight hair are located).

Once they have this map, scientists can test for the presence or absence of the QTL in a population. This means that if you have the gene linked to curly hair in your family, it is likely that your hair will be curly too.

So, in summary, a quantitative trait locus is a map that helps us find the genes responsible for certain traits, and by testing for the presence of these genes, we can predict whether someone will have a trait or not.