Roots and Shoots

Seed to STEM
Grade Level: Middle School

Many students have previous experience germinating seeds, but in my experience, few have thought much about
how plants grow in the correct orientation. How do plants send roots into the soil and shoots up to gather light?
This activity is designed for students to propose and design experiments as well as identify the stimulus that
plants rely on to determine which way is up.

In this lab, students will observe ears of corn from F2 plants produced by a dihybrid cross for the traits of kernel color and endosperm composition, which changes the shape of the kernel. The color blue is dominant to yellow, and the starchy nonwrinkled endosperm is dominant to a sugary wrinkled endosperm. Students will hypothesize the genotypes of the parents (F1 generation). First, students will look at each trait independently, then look at the independent assortment or linkage between the two traits. These hypotheses will be used to make predictions that will be analyzed by collecting data and applying a chi-square test.

Pictures from the Lab

Pictures to come.

Quick Resources

  • Print the lab
  • Student Worksheet
  • Answers to Student Worksheet
  • Power Point