Scientists love their little codes. A dominant trait is written with a capital letter. Recessive gets a lowercase one. So, “B” for brown eyes, “b” for blue.
If your genetic code is “BB” or “Bb,” you’ve got brown eyes. The capital B dominates its lowercase buddy. Only “bb” gives you blue.
It’s that simple. No need for a PhD in genetics. Just remember: capital = shouty; lowercase = shy.
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But Wait, It’s Not Always That Obvious
Before you get too cocky, know that life isn’t always so black-and-white. Some traits are incomplete dominant. That’s a fancy way of saying they’re a compromise.
Think of a red flower and a white flower having a pink baby. Neither trait is the total bully. They blend instead. It’s like a genetic hair color that can't decide if it wants to be blonde or brunette.
And then there’s co-dominance. That’s where both traits show up at the same time. Like a cow with black and white splotches. Both genes say, “No, you move!” and neither wins. Drama!
