Name: ______________________________
Date: _____________________
Punnett Squares: Codominance and Incomplete Dominance
What is carried within DNA? ______________________________________________________
How is this information carried? ___________________________________________________
Define gene ___________________________________________________________________
Define allele ___________________________________________________________________
Define genotype ________________________________________________________________
What does it mean if a gene has been expressed? _____________________________________
______________________________________________________________________________
What does unexpressed mean? ___________________________________________________
Define phenotype _______________________________________________________________
Define homozygous: ____________________________________________________________
Define heterozygous: ____________________________________________________________
Complete the table using the information below:
What does it mean if genes are codominant? _________________________________________
What is an example of genes that are codominant? ____________________________________
1. A person with genotype IAIA has blood type ______
2. A person with genotype IAi has blood type ______
3. A person with genotype IBIB has blood type ______
4. A person with genotype IBi has blood type ______
5. A person with genotype ii has blood type ______
6. A person with genotype IAIB has blood type ______
Why is blood type O recessive? ____________________________________________________
Why are blood type A and blood type B codominant? __________________________________
______________________________________________________________________________
IAi (♂) x IAIA (♀)
IAi (♂) x IBi (♀)
IAIA (♂) x IAIB (♀)
IAi (♂) x IBIB (♀)
IBi (♂) x IBi (♀)
ii (♂) x IAIB (♀)
IAIA (♂) x ii (♀)
IAi (♂) x IAIB (♀)
How would you define incomplete dominance? _______________________________________
______________________________________________________________________________
What type of phenotype does incomplete dominance produce? __________________________
1. A species of flowers exhibits incomplete dominance between
the allele for red flowers and the allele for white flowers. If a
plant homozygous for red flowers is crossed with a plant that is
homozygous for white flowers, what percentage of offspring will
have pink flowers? _____________
2. A species of flowers exhibits incomplete dominance between
the allele for red flowers and the allele for white flowers. If
two heterozygous, pink plants are crossed, what percentage of
each color of flower will appear in the offspring?
% red _______
rr (♂) x Rr (♀)
1. What percentage
of offspring will be
pink?
_____________
% pink _______
% white _______
Rr (♂) x Rr (♀)
2. How many
phenotypes would be
seen in the offspring?
_____________
Rr (♂) x rr (♀)
3. What percentage
of offspring will be
white?
_____________
RR (♂) x Rr (♀)
4. What percentage
of offspring will be
red?
_____________