SOLUTION: Pedigree worksheet key - Studypool - Free Printable

Let’s look at each pedigree chart one by one and figure out what kind of inheritance pattern is shown.

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First Pedigree (top, with red shapes):

- The trait appears in every generation — that suggests it’s dominant, because recessive traits often skip generations.
- Affected individuals have at least one affected parent — again, supports dominant inheritance.
- Both males and females are affected — so it’s not sex-linked (like X-linked).
- Look at individual I-1 (affected male) and I-2 (unaffected female). They have both affected and unaffected children. That fits autosomal dominant: if the father is heterozygous (Aa), he can pass either A or a to kids.
- Also, when two unaffected people (like II-4 and II-5) have kids, all their kids are unaffected — which makes sense for dominant: if you don’t have the allele, you can’t pass it on.
→ So this is likely autosomal dominant.

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Second Pedigree (middle, mostly blank except bottom right):

- Only a few people are affected — and they appear in the same generation, but their parents are unaffected.
- Specifically, look at the bottom: two unaffected parents (III-? and III-?) have an affected son and daughter.
→ This is classic recessive inheritance: parents are carriers (heterozygous), and child gets two copies of the mutant allele.
- Also, affected individuals are both male and female → not sex-linked.
→ So this is autosomal recessive.

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Third Pedigree (bottom, blue shapes + half-filled circles):

- Half-filled symbols usually mean “carrier” — common in recessive disorders.
- But here, we see affected individuals (fully filled) appearing in multiple generations, and sometimes from unaffected parents? Wait — let’s check:
- Generation I: affected male (blue square) marries unaffected female → some kids are carriers (half-filled), none fully affected? Actually, no — in generation II, there are no fully affected, only carriers and normals.
- Then in generation III: two carriers marry → produce affected offspring (fully blue squares/circles).
- Also, note: affected males and females exist → not X-linked recessive (which would affect mostly males).
- And carriers are shown — which is typical for recessive conditions.
→ So this is also autosomal recessive.

Wait — but hold on! In generation IV, we see affected individuals born to parents where one is affected and one is carrier? Or normal? Let’s trace:

Actually, looking closely:
In generation III, there’s a mating between a carrier female (half-circle) and an affected male (full square) → they have affected and carrier children. That still fits autosomal recessive: if mom is Aa, dad is aa → kids can be Aa or aa.

Also, in another branch: two carriers (both half-symbols) have affected kids — yes, 25% chance.

So yes — third pedigree is autosomal recessive.

But wait — why are there so many carriers shown? Because it’s probably illustrating how recessive traits can hide in carriers and then show up later.

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Now, let’s double-check:

Pedigree 1: Dominant — affects every generation, affected kids have affected parents, no skipping.

Pedigree 2: Recessive — skips generations, unaffected parents have affected kids.

Pedigree 3: Recessive — carriers shown, affected kids come from carrier parents or carrier + affected.

All three follow Mendelian patterns.

Final conclusion:

Top: Autosomal Dominant
Middle: Autosomal Recessive
Bottom: Autosomal Recessive

But the question might be asking to identify the mode for each — since no specific question was written, based on standard homework, we assume we’re to label each pedigree’s inheritance pattern.

Final Answer:
Top pedigree: Autosomal Dominant
Middle pedigree: Autosomal Recessive
Bottom pedigree: Autosomal Recessive