Name___________________________
Punnett Squares Day 2 Practice
Important Vocabulary Terms:
An ​ allele​ is the gene form for each variation of a trait.
A ​dominant ​trait is one that is always seen. It takes only 1 dominant allele to look dominant. We use capital
letters to represent a dominant allele.
A ​recessive​ trait is one that is covered up by the dominant allele. It takes 2 recessive alleles to look recessive.
We use a lower case letter to represent a recessive allele.
The ​genotype i​ s the gene combination for a trait (represented by two letters) ,
while the​ phenotype​ is what that trait physically looks like.
Heterozygous​ alleles are different (this is also called a ​hybrid​). Remember ​hetero​ means different.
Homozygous​ alleles are the same (this is also called ​pure​). Remember​ homo ​means the same.
1. A green pea plant (Gg) is crossed with a yellow pea plant (gg).
How many of the offspring will be green? ___/4_______________
How many of the offspring will be yellow? ___/4_______________
How many of the offspring will be homozygous? ____/4______________
How many of the offspring will be heterozygous? ____/4______________
2. A tall plant (TT) is crossed with a tall plant (Tt).
How many of the offspring will be tall? __________________
How many of the offspring will be short? __________________
How many of the offspring will be homozygous? __________________
How many of the offspring will be heterozygous? __________________
3. A tall plant (Tt) is crossed with a short plant (tt).
How many of the offspring will be tall? __________________
How many of the offspring will be short? __________________
How many of the offspring will be homozygous? __________________
How many of the offspring will be heterozygous? __________________
4. A red flower (Rr) is crossed with a white flower (rr).
How many of the offspring will have red flowers? __________________
How many of the offspring will have white flowers? __________________
How many of the offspring will be homozygous? __________________
How many of the offspring will be heterozygous? __________________
5. ​A white flower (rr) is crossed with a white flower (rr).
How many of the offspring will have red flowers? __________________
How many of the offspring will have white flowers? __________________
How many of the offspring will be homozygous? __________________
How many of the offspring will be heterozygous? __________________