Incomplete Dominance - Incomplete dominance is a form of intermediate inheritance in which one allele for a specific trait is not completely dominant over the other allele. This results in a combined phenotype. In Snapdragon Flowers, there are white (W), pink, and red flowers (R). 1. What is the phenotype for the following genotypes:
WW __________________
WR __________________
RR __________________
WW - white flowers
WR - pink flowers
RR - red flowers
Set up the square for each of the crosses listed below:
WW x RR
What percentage of the offspring will be:
- White: __________
- Pink: ___________
- Red: ___________
To determine the outcome of the cross between WW and RR, we need to consider incomplete dominance, where the heterozygous genotype (WR) results in a pink phenotype.
The Punnett square for the cross between WW and RR would look like this:
R R
W WR WR
From this Punnett square, we can determine the phenotype ratios:
- White: 0%
- Pink: 100%
- Red: 0%
Therefore, 100% of the offspring will have a pink phenotype.
WR x WR
What percentage of the offspring will be:
- White: __________ - Pink: ___________ - Red: ___________
To determine the outcome of the cross between WR and WR, we need to consider incomplete dominance, where the heterozygous genotype (WR) results in a pink phenotype.
The Punnett square for the cross between WR and WR would look like this:
W R
W WW WR
R WR RR
From this Punnett square, we can determine the phenotype ratios:
- White: 25%
- Pink: 50%
- Red: 25%
Therefore, 25% of the offspring will have a white phenotype, 50% will have a pink phenotype, and 25% will have a red phenotype.
Co-dominance - the heterozygote displays the phenotypic characteristics of both alleles. In a specific type of chicken, when you combine a white-feathered chicken (W) with a black-feathered chicken (B), you get black feathers with white tips.
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3. What is the phenotype for the following genotypes:
WW ___________________________
WB ____________________________
BB ____________________________
WW - white feathers
WB - black feathers with white tips
BB - black feathers
Set up the square for each of the crosses listed below:
WW x BB
What percentage of the offspring will be:
Color
percentage
- _____________: ___________ - _____________: ___________ - _____________: ___________
To determine the outcome of the cross between WW and BB, we need to consider co-dominance, where the heterozygous genotype (WB) results in black feathers with white tips.
The Punnett square for the cross between WW and BB would look like this:
B B
W WB WB
W WB WB
From this Punnett square, we can determine the phenotype ratios:
- White feathers: 0%
- Black feathers with white tips: 100%
- Black feathers: 0%
Therefore, 100% of the offspring will have black feathers with white tips.
What percentage of the offspring will be:
Color percentage
- _____________: ___________ - _____________: ___________ - _____________: ___________