We're studying genetics in bio but I have a question. Why do I have blonde hair but my parents don't

My mothers side is all red head, and my dads side is like burnetts. My dad is said to be blonde but was more brunette. And my 2 older sisters are brunette. One was blonde like me (all natural) and then it turned dark brunette BUT i didn't i'm the only blondie...HOW?

Hair color is almost certainly a polygenetic trait. That means that there is not one gene that controls the trait. In addition, it appears that there are many alleles (versions) of each gene. That means that a blond is not a blond is not a blond. Hair color is determined by the amount of two pigments; brown-black eumelanin predominates in black and brown hair and red-yellow pheomelanin in red hair. Blond hair contains low levels of both pigments. Depending on the exact code of the gene for eumelanin, it can produce variations in color. In addition, hair color doesn't remain steady throughout ones life. There are changes that occur in the follicles that are under the control of various regulatory hormones.

Clearly in your case, your mother had at least one red allele and your dad had at least one brown allele. Their other alleles could have low pigment (blond) alleles. That makes red, brown and blond on the list of possibles.

The allele for blonde hair is recessive to the dominant brown hair allele. In other words, someone can have brown/black hair and still be a carrier of the unexpressed blonde or red allele. Your parents must each be heterozygous carriers. I hope that made sense.

It happens. My friend is blonde out of a family of red heads. It just deals with the arrangement of chromosomes, and your hair might turn a darker color over time.

Betsy nailed it perfectly.

Good question. Both blonde and red hair are recessive genes so I'd be asking some questions....

Some one was blond like you.
Ask your biology teacher about traits of hair color.

u have the recessive mutant gene, that has given u blond hair and blue eyes....