Bio punnet squares and pedigrees

Simple (Mendelian) Inheritance

One allele is dominant, the other is recessive

Codominance

Both alleles show up fully at the same time

Incomplete Dominance

Traits blend together

Multiple Alleles

More than 2 allele options exist for a gene

Sex-Linked Inheritance

Gene is on a sex chromosome

Dihybrid Inheritance

Tracks 2 traits at once

Dominant

At least one parent ALWAYS has to have the disorder in the pedigree if the trait is passed

Recessive

Neither parent has to have the disorder for the trait to be passed on in the pedigree.

Sex Linked/X-linked traits

Men with affected mothers will always get the trait (mom gives you your X chromosome);Affected men will have daughters that are always carriers

Autosomal Traits

About even men and women affected in large populations; Affected mothers do not have all affected sons.

Autosomal Dominant

only 1 copy needed (shows up every generation)

Autosomal Recessive

need 2 copies (can skip generations)

X-Linked Inheritance

• Males (XY) are hit harder
  → only one X, so no backup copy 😬

• 👧 Females (XX) usually need 2 copies to show it

• 🚫 Fathers cannot pass X-linked traits to sons
  (they give sons a Y chromosome)

• 👩 Moms can pass it to both sons and daughters