Name________________________________________________Date__________Block___
Punnett Square Practice
Define Homozygous- _____________________________________________________
Define Heterozygous- _____________________________________________________
Directions: Circle all the heterozygous genotypes & Underline the homozygous genotypes:
BB
bb
Bb
Tt
FF
ff
Ff
GG
Gg
gg
Rr
Qq
NN
MM
Mm
Dd
The trait is freckles:
F= freckles ; f= no freckles
1.) Which trait is dominant? ___________________
How do you know? ___________
_________________________________________________________________________
2.) Which trait is recessive? ___________________ How do you know? ____________
_________________________________________________________________________
3.) List the genotype for a person who is heterozygous for freckles. ________________
4.) List the genotype for a person who is homozygous for freckles. ________________
5.) List the genotype for a person who is homozygous for no freckles. ______________
6.) If the genotype is ff , what would the phenotype be? __________________________
7.) If the genotype is FF, what would the phenotype be? _________________________
8.) If the genotype is Ff, what would the phenotype be? __________________________
9.) Define Purebred- ______________________________________________________
10.) Define Hybrid- ________________________________________________________
Name________________________________________________Date__________Block___
Punnett Square Practice
11.)
Parent 1 is heterozygous for freckles. What is the genotype? ____________
12.)
Parent 2 is homozygous for freckles. What is the genotype? _____________
13.)
Cross the 2 parents from questions 11 and 12 in the Punnett Square.
14.)
15.) Out of the 4 possibilities you created in the Punnett Square answer the following
questions:
a. What percent have a homozygous genotype? __________% or _______out of 4
o List the homozygous genotypes from the Punnett Square. _________________
b. What percent have a heterozygous genotype? __________% or _______out of 4
o List the heterozygous genotypes from the Punnett Square. ________________
c. What percent have freckles as their phenotype? __________% or _______out of 4
d. What percent has no freckles as their phenotype? __________% or _______out of 4
e. What percent would be considered hybrid? __________% or _______out of 4
o List the hybrids: _________________________________________________
f. What percent would be considered purebred? __________% or _______out of 4
o List the purebreds: ________________________________________________