What are dominant and recessive alleles?

A dominant allele is like the loud kid in class who always gets heard first, and a recessive allele is like the quiet kid who only speaks up when no one else is talking.

Imagine you have a box of crayons. Each crayon represents an allele, half comes from your mom, and half comes from your dad. Now, if you get a red crayon from both parents, your picture will be super red. But if you get a red crayon from one parent and a blue crayon from the other, the dominant red will show up more in your drawing, just like how some traits are more noticeable than others.

What Happens When You Have Both?

Sometimes, you might get two different colors: say, red from mom and blue from dad. The dominant one (red) shows up as the main color in your picture, while the recessive one (blue) stays hidden, but it's still there!

What If You Get Two of the Same?

If you get two blues or two reds, both colors will show up fully. That’s like when a kid has two quiet friends, they can finally be heard too!

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Examples

A brown-eyed parent and a blue-eyed parent have a child with brown eyes because the brown eye allele is dominant.
Like a loudspeaker in a quiet room, dominant alleles often overshadow recessive ones.
If both parents pass on a recessive allele for curly hair, the child will have curly hair.

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Categories: Biology · alleles· genetics· inheritance