Hey future Biologists! Today we're diving into the ABO blood group system, a fantastic example of multiple alleles. Why is it important? Well, if you've ever needed a blood transfusion (or even if you haven't), knowing about blood groups can literally be a lifesaver! 🚑

Multiple Alleles 🧬

• One gene but more than two forms (alleles).
• For example, ABO blood group system has three alleles: IA, IB, and i.

• Genotype: The actual genetic makeup (IAIA, IBIB, IAi, etc.)
• Phenotype: What's observable (blood group A, B, AB, or O)

• You have to match blood groups before transfusions.
• If not, red blood cells can coagulate (clump together), which is a big NO-NO!

🌟 Real-world Example: Imagine you're making a smoothie. If you mix the right ingredients, it's delicious. If not, you'll end up with a chunky mess. The same goes for blood transfusion; the ingredients (blood types) must match!

• IA: Adds something called acetylgalactosamine to the glycoprotein in red blood cells.
• IB: Adds galactose to the glycoprotein.
• i: Does nothing to the glycoprotein, the lazy one in the group!

Superpowers or Weaknesses?

• IA and IB are dominant over i.
• IA and IB are codominant with each other.

🌟 Real-world Example: Think of IA and IB as strong siblings in a tug-of-war game who can easily defeat their little sibling "i." But when IA and IB compete against each other, it's a tie!