Question

whether they are homozygous dominant, or heterozygous, or homozygous recessive for a particular trait.
figure 4
which of the punnett squares below would best describe figure 4?
(a)
(b)
(c)

Explanation:

Step1: Analyze Pedigree

In Figure 4, the parents (white square and white circle) have a affected child (black square). For a recessive trait, affected individuals (homozygous recessive, \( ff \)) have parents who are carriers (heterozygous, \( Ff \)) or have the recessive allele.

Step2: Analyze Punnett Squares

• Option A: Parents are \( Ff \) (top: \( F,f \); side: \( F,f \)). Offspring can be \( FF, Ff, Ff, ff \). This allows for a recessive (\( ff \)) child from heterozygous parents.
• Option B: Parents are \( FF \) (top: \( F,F \); side: \( F,F \)). All offspring are \( FF \), no recessive.
• Option C: Parents are \( Ff \) (top: \( F,f \)) and \( ff \) (side: \( f,f \)). Offspring would be \( Ff, ff, Ff, ff \), but one parent would be affected (black), which doesn't match the pedigree (both parents white, so not affected).

So the pedigree (unaffected parents, affected child) matches a cross of two heterozygotes (\( Ff \times Ff \)), which is Punnett Square A.

Answer:

A. The Punnett Square labeled (A)