These numbers are comparable to a small shuttle colony. For this activity, yields and growing times can be based upon the germination information listed in books or on the backs of packages of seeds. Naturally, the estimates published on seed packages are based upon the Earth's growing conditions. Students should already be familiar with the concept of gravity. Roots also stabilize the plant, and keep it from bring blown or washed away on Earth.
Leaves grow out of the stem.
Students integrate and apply their knowledge of hydroponic systems and the effect of gravity on plant growth by designing a hydroponic system for use in space. They communicate their ideas verbally and in labeled drawings. A little bit about the difference between science and technology. For more science background on hydroponics and microgravity, please read the Teacher Background sections in the activities in No Soil and in Geo Seeds.