Evidence for How Plants Grow: teacher key

How Plants Grow, grade 12 edition, written for 12th grade and up. The experiments, measurements and open trade-offs behind how a seed becomes a plant, from willow weights to fungus networks.

Read the book. Print this page for the key.

Questions and answers

1. What is typically the main force that moves water up in a plant?
   • Root pressure
   • Transpiration (answer)
   • Pollen
2. Why is cross-pollination preferable to self-pollination?
   • It produces more genetic diversity (answer)
   • It needs no petals
   • It makes seeds float
3. What can be inferred from Ingen-Housz's results about a plant in a sealed dark chamber?
   • It makes extra oxygen
   • It uses up oxygen, like a mouse or a candle (answer)
   • It stops using water
4. What is true of the trade between trees and fungi?
   • It is always even
   • Fungi give sugars to trees
   • Some species may draw more than they give (answer)
5. What does the word transpire describe?
   • A plant losing water vapor (answer)
   • A seed taking in water
   • A root finding soil

Words

• endosperm: seed food store
• transpiration: plant water loss
• gravitropism: growing with gravity
• phytoplankton: tiny ocean plants