1. Punnett Square
By Mrs. Henning
NOHS
2012

2. Simple Dominance Dominant Alleles Represent with a capital letter
If the dominant allele is present, it always shows up.
Recessive Alleles
Represented with a lowercase letter
Only shows up if there are NO dominant alleles
Example: Red is dominant to white.
R= Red
r = white
RR = Red
Rr = Red
rr = White

3. Genotypes and Phenotypes
Genotype refers to the alleles present.
Genotypes can be
Homozygous dominant (HH)
Heterozygous (Hh)
Homozygous recessive (hh)
Phenotype refers to the outward appearance of those alleles.
Red hair, brown eyes, white fur, etc.

4. What is it called? BB Bb bb Yy CC Dd TT ee Pp EE Homozygous Dominant
Heterozygous
Heterozygous
Homozygous Dominant
Homozygous Recessive
Homozygous Recessive
Heterozygous
Heterozygous
Homozygous Dominant
Homozygous Dominant

5. What will the genotype and phenotype be?
B = Blue b = White BB Bb bb
Homozygous Dominant
Heterozygous
Homozygous Recessive
Blue
Blue
White

6. What will the phenotype be?
R = Red r = Yellow RR Rr rr
Homozygous Dominant
Heterozygous
Homozygous Recessive
Red
Yellow
Red

7. Dominant Alleles American Curled Cat Curled Ear is Dominant EE or Ee
Normal Ears is Recessive ee

8. If you have a normal eared cat and mated it with a heterozygous American Curled cat, how likely are you to have kittens with curled ears?
E =
Curled Ears
e =
Normal Ears
Normal Ears
Heterozygous
Parent Genotype = ee x Ee

9. e e E E e E e e e e e e Put One Genotype Here And the other one here
Parent Genotype:
Ee x ee
Put One Genotype Here e e E E e E e
And the other one here e e e e e

10. e e E e E e e e Remember: E = Curled Ear e = Normal (straight) Ear
Genotype: Ee ee
Phenotype:
Ee =
ee =
E e
e e E 2 2 e
2 Ee :
2 ee
1 Ee : 1 ee
Curled Ears
Normal (Straight) Ears
2 Curled Ears :
2 Normal Ears
1 Curled Ears :
1 Normal Ears

11. Make sure to answer the question!
If you have a normal eared cat and mated it with a heterozygous American Curled cat, how likely are you to have kittens with curled ears?
E e
e e
How many will have curled ears?
2 out of how many
2 out of 4 = 50% chance

12. Folded Ears are dominant to normal ears
Scottish Fold
F =
Folded Ears
f =
Normal Ears
Folded Ears are dominant to normal ears

13. If you have two heterozygous cats for folded ears, what is the chance of having kittens with normal ears?
F =
Folded Ears
f =
Normal Ears
Heterozygous
Parent Genotype = Ff x Ff

14. F f F F F F f f f F f f Put One Genotype Here And the other one here
Parent Genotypes:
Ff x Ff
Put One Genotype Here F f F F F F f
And the other one here f f F f f

15. F f F F F f f f F f Remember: F = Folded Ear f = Normal (straight) Ear
Genotype: FF Ff ff
F F
F f
f f F 1
Folded Ears 2
Folded Ears
Normal (Straight) Ears 1 f
What is the chance of getting normal ears?
Phenotypic Ratio
3 Folded: 1 Normal
Normal Ears
¼ = 25%

16. Alleles: R r Parent Genotype:
A heterozygous round pea is crossed to a homozygous wrinkled pea. What are the possible phenotypes and genotypes of the offspring?
Alleles: R r Parent Genotype:
= Round
= Wrinkled
Rr x rr