I/GCSE Biology - Using plant hormones

In I/GCSE Biology, using plant hormones is important! 👍

You should know:

Two ways to kills weeds

1. Pull out each weed by hand
2. Spray lawn with selective weed killers

• 2,4-D ➡️ similar structure to auxins, has greater effect
• Absorbed by broad-leaved plants – accumulates in stem + root tips ➡️ causes uncontrolled growth
• Plant dies, 2,4-D not absorbed by narrow-leaved plants e.g. grass

Do you remember what agent orange is in I/GCSE Biology?

• Caused leaves to fall off in jungle
• Significant increase of children born with birth defects
• Also causes diseases

• Cutting used to produce large numbers of identical plants
• Part of plant is cut off and stem is dipped in rooting powder
• End of stem then placed in compost
• Roots develop from cut stem
• Rooting powders contain auxins ➡️ stimulate the stem cells to develop into roots

• Gas ethane (ethylene) = plant hormone
• Produced by fruits as they ripen
• Stimulate reactions = convert starch into sugar

References:

1. "weed killer". Image form the internet.
2. "agent orange". Image form the internet.
3. "Rooting powders". Image form the internet.
4. "Plant Hormones Tissues Tropisms Agricultural Botany Biology 20", https://slidetodoc.com/presentation_image_h/279a370cc367465a13bb2d45fe48fd86/image-8.jpg

And we're done with this topic! Well Done!

CLICK HERE TO LEARN MORE ABOUT OUR I/GCSE BIOLOGY COURSES

Drafted by Alyssa (Biology)