Question

shelley, one of gary’s cousins, has a beautiful hot pink shell that is a result of incomplete dominance. the gene for a red shell is represented with an r, while w is used the gene for a white shell. a snail with both of those genes (rw) has a pink shell. use this information to answer the questions.

1. if a snail with a red shell were crossed with one with a white shell, what color shell would the children have? create a punnett square to help you. explain.

1. sherry, who is a pink - shelled snail, would like to have kids with red shells. what type of snail would she need to marry in order for the best chance for kids with red shells? explain your answer.

Explanation:

Step1: Define parental genotypes

Red shell snail: $RR$, White shell snail: $WW$

Step2: Set up Punnett Square

	$R$	$R$
$W$	$RW$	$RW$

Step3: Interpret offspring genotypes

All offspring have $RW$ genotype. Per incomplete dominance, $RW$ = pink shell.

Step4: Analyze Sherry's genotype

Sherry (pink shell) = $RW$. To get red-shelled ($RR$) offspring, mate with $RR$ (red shell) snail.

Step5: Punnett Square for Sherry × red snail

	$R$	$W$
$R$	$RR$	$RW$

Step6: Calculate offspring probability

50% chance of $RR$ (red shell), highest possible odds.

Answer:

1. All of the offspring snails will have pink shells. The Punnett square shows every offspring inherits one $R$ allele from the red-shelled parent and one $W$ allele from the white-shelled parent, resulting in the $RW$ genotype which produces a pink shell due to incomplete dominance.
2. Sherry needs to marry a red-shelled (genotype $RR$) snail. When a $RW$ (pink) snail mates with an $RR$ (red) snail, 50% of the offspring will have the $RR$ genotype (red shell), which is the highest possible chance of getting red-shelled offspring. Mating with a white or pink snail would result in 0% or 25% red-shelled offspring respectively.