5.3 Mendelian Genetics
Notes
- Law of segregation: alleles separate into different gametes.
- Law of independent assortment: genes on different chromosomes sort independently.
- $Aa\times Aa$ gives 3:1 phenotypes; $AaBb\times AaBb$ gives 9:3:3:1.
- Probability: multiply for "and," add for "or."
Practice
$Aa\times Aa$: probability of $aa$:
$\displaystyle \frac{1}{2}\cdot\frac{1}{2}$.
$AaBb\times AaBb$: probability of $aabb$:
$\displaystyle \frac{1}{4}\cdot\frac{1}{4}$.
A test cross mates an individual with:
Reveals the unknown genotype.
Ready for more? Take the Unit 5 test.