College

Select the correct answer from each drop-down menu.

1. If a heterozygous male with the genotype [tex]Ww[/tex] is mated with a homozygous recessive female of genotype [tex]ww[/tex], there is a [tex]\square[/tex] chance that the offspring will be heterozygous.

[tex]
\[
\begin{array}{|c|c|c|}
\hline & W & w \\
\hline w & Ww & ww \\
\hline w & Ww & ww \\
\hline
\end{array}
\]
[/tex]

2. If the heterozygous [tex]Ww[/tex] is crossed with a homozygous dominant [tex]WW[/tex], then the probability of having a homozygous recessive offspring is [tex]\square[/tex].

[tex]
\[
\begin{array}{|c|c|c|}
\hline & W & w \\
\hline W & WW & Ww \\
\hline W & WW & Ww \\
\hline
\end{array}
\]
[/tex]

Answer :

We begin by analyzing each cross separately.

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Cross 1: Heterozygous Male ([tex]$Ww$[/tex]) × Homozygous Recessive Female ([tex]$ww$[/tex])

1. The heterozygous male has genotype [tex]$Ww$[/tex], so his possible gametes are [tex]$W$[/tex] and [tex]$w$[/tex].
2. The homozygous recessive female has genotype [tex]$ww$[/tex], so her only possible gamete is [tex]$w$[/tex].

Setting up the Punnett square:

[tex]$$
\begin{array}{c|cc}
& W & w \\ \hline
w & Ww & ww \\
w & Ww & ww \\
\end{array}
$$[/tex]

3. From the Punnett square, we see that out of the four possible combinations, two are heterozygous ([tex]$Ww$[/tex]).
4. This tells us that [tex]$\dfrac{2}{4} = \dfrac{1}{2}$[/tex] of the offspring, which is 50%, will be heterozygous.

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Cross 2: Heterozygous ([tex]$Ww$[/tex]) × Homozygous Dominant ([tex]$WW$[/tex])

1. The heterozygous individual ([tex]$Ww$[/tex]) produces gametes [tex]$W$[/tex] and [tex]$w$[/tex].
2. The homozygous dominant individual ([tex]$WW$[/tex]) produces only [tex]$W$[/tex] gametes.

Setting up the Punnett square:

[tex]$$
\begin{array}{c|cc}
& W & W \\ \hline
W & WW & WW \\
w & Ww & Ww \\
\end{array}
$$[/tex]

3. All offspring will have at least one dominant [tex]$W$[/tex] allele. There are no offspring with the genotype [tex]$ww$[/tex], which would be homozygous recessive.
4. Thus, 0% of the offspring will be homozygous recessive.

--------------------------------------------------

Final Answers:

- 50% of the offspring from the cross between a heterozygous male ([tex]$Ww$[/tex]) and a homozygous recessive female ([tex]$ww$[/tex]) will be heterozygous.
- 0% of the offspring from the cross between a heterozygous individual ([tex]$Ww$[/tex]) and a homozygous dominant individual ([tex]$WW$[/tex]) will be homozygous recessive.