Answer :
Let's work through each cross step by step.
1. For the cross between a heterozygous male ([tex]$Ww$[/tex]) and a homozygous recessive female ([tex]$ww$[/tex]):
- The male produces two types of gametes: one carrying the [tex]$W$[/tex] allele and one carrying the [tex]$w$[/tex] allele, each with a probability of 0.5.
- The female can only produce gametes carrying the [tex]$w$[/tex] allele.
Therefore, the possible offspring are:
- If the male’s gamete is [tex]$W$[/tex], the offspring’s genotype will be [tex]$Ww$[/tex] (heterozygous).
- If the male’s gamete is [tex]$w$[/tex], the offspring’s genotype will be [tex]$ww$[/tex] (homozygous recessive).
Since half of the male’s gametes carry [tex]$W$[/tex], the probability of obtaining a heterozygous ([tex]$Ww$[/tex]) offspring is
[tex]$$ 0.5 \text{ or } 50\%. $$[/tex]
2. For the cross between a heterozygous individual ([tex]$Ww$[/tex]) and a homozygous dominant individual ([tex]$WW$[/tex]):
- The heterozygous individual produces gametes: one carrying [tex]$W$[/tex] and one carrying [tex]$w$[/tex], each with a probability of 0.5.
- The homozygous dominant individual can only produce gametes carrying the [tex]$W$[/tex] allele.
Therefore, the possible offspring are:
- If the heterozygous partner produces a [tex]$W$[/tex] gamete, the offspring’s genotype will be [tex]$WW$[/tex] (homozygous dominant).
- If the heterozygous partner produces a [tex]$w$[/tex] gamete, the offspring’s genotype will be [tex]$Ww$[/tex] (heterozygous).
Notice that there is no possibility for a [tex]$ww$[/tex] (homozygous recessive) offspring in this cross. Thus, the probability of having a homozygous recessive offspring is
[tex]$$ 0.0 \text{ or } 0\%. $$[/tex]
To summarize:
- The chance that [tex]$50\%$[/tex] of the offspring will be heterozygous in the first cross.
- The probability that there will be any homozygous recessive offspring in the second cross is [tex]$0\%$[/tex].
1. For the cross between a heterozygous male ([tex]$Ww$[/tex]) and a homozygous recessive female ([tex]$ww$[/tex]):
- The male produces two types of gametes: one carrying the [tex]$W$[/tex] allele and one carrying the [tex]$w$[/tex] allele, each with a probability of 0.5.
- The female can only produce gametes carrying the [tex]$w$[/tex] allele.
Therefore, the possible offspring are:
- If the male’s gamete is [tex]$W$[/tex], the offspring’s genotype will be [tex]$Ww$[/tex] (heterozygous).
- If the male’s gamete is [tex]$w$[/tex], the offspring’s genotype will be [tex]$ww$[/tex] (homozygous recessive).
Since half of the male’s gametes carry [tex]$W$[/tex], the probability of obtaining a heterozygous ([tex]$Ww$[/tex]) offspring is
[tex]$$ 0.5 \text{ or } 50\%. $$[/tex]
2. For the cross between a heterozygous individual ([tex]$Ww$[/tex]) and a homozygous dominant individual ([tex]$WW$[/tex]):
- The heterozygous individual produces gametes: one carrying [tex]$W$[/tex] and one carrying [tex]$w$[/tex], each with a probability of 0.5.
- The homozygous dominant individual can only produce gametes carrying the [tex]$W$[/tex] allele.
Therefore, the possible offspring are:
- If the heterozygous partner produces a [tex]$W$[/tex] gamete, the offspring’s genotype will be [tex]$WW$[/tex] (homozygous dominant).
- If the heterozygous partner produces a [tex]$w$[/tex] gamete, the offspring’s genotype will be [tex]$Ww$[/tex] (heterozygous).
Notice that there is no possibility for a [tex]$ww$[/tex] (homozygous recessive) offspring in this cross. Thus, the probability of having a homozygous recessive offspring is
[tex]$$ 0.0 \text{ or } 0\%. $$[/tex]
To summarize:
- The chance that [tex]$50\%$[/tex] of the offspring will be heterozygous in the first cross.
- The probability that there will be any homozygous recessive offspring in the second cross is [tex]$0\%$[/tex].
