Student Worksheet—Biology
Strand: Heredity and Evolution
Name___________________________ Date__________________ School_________________
Student—please print this worksheet and complete it as you interact with the tutorial. The
completed worksheet should be turned in to your assigned teacher.
Tutorial: Mendel’s Peas (Punnett Squares)
Directions: Read the dialogue box and follow the directions the animated Gregor Mendel gives
you. Answer the following questions as you proceed through the tutorial.
1. What plant did Mendel use in his studies? _________________________________
2. Plant five pea plants and record their descriptions below (Pea and pod descriptions):
a. _______________________________________
b. _______________________________________
c. _______________________________________
d. _______________________________________
e. _______________________________________
3. How many different pea traits do you see in the five plants? ______________
4. Traits that tend to mask, or hide, the other traits are described as _____________ traits.
5. Those traits that tend to be hidden by dominant traits are called ______________ traits.
Pedigree
6. Using the traits Mendel offers, (flower color, pea shape, etc) determine which traits are
dominant in the pea plants. Circle the correct option for each.
a. Flower color: white or purple
b. Pea shape: round or wrinkled
c. Pea color: green or yellow
d. Pod Shape: constricted or inflated
e. Pod Color: green or yellow
f. Plant size: tall or dwarf
g. Position of flowers: axial or terminal
Directions: When you have completed Mendel’s experiments, go to the following website:
http://library.thinkquest.org/17109/game.htm
7. Fill in the table below for a cross between two homozygous dominant parents (TT x TT).
T
T
T
T
b. What percentage of the offspring will be tall pea plants?
8. Fill in the table below for a cross between two heterozygous parents:
T
t
T
t
b. What percentage of the offspring are tall pea plants (TT or Tt genotype)?
c. What percentage of the offspring are short pea plants (tt genotype only)?
d. What is the ratio among the offspring genotypes (how many of each are present)?
______TT: ________Tt:________tt