Fruit Development & Dispersing Fruits and Seeds

1. Fruit Development & Dispersing Fruits and Seeds How to get around when you’re rooted in the ground

2. Review of prior learning What did you already learn about fruits?

3. Fruit Development When the ovary is fertilized it begins to swell. This is called a FRUIT SET.

4. Fruit Development is driven by hormones • Our old friend Auxin is involved • We also see a new player, the hormone giberellin • If you apply auxin or gibrellin to the ovaries of unfertilized flowers you develop parthenocarpic (seedless) fruits Fruit Development: Hormones

5. Fruits ripen when seeds are ready for dispersal What does it look like when fruit ripens? Changing from green to another color Sweetening Softening

6. Seed Dispersal Plants can’t move around like animals They have to get creative; you can’t just let the offspring grow on top of the parents Seed dispersal is how they move their seeds.

7. Wind Dispersal Some seeds and fruits can be carried on the wind. Maple seeds act like little helicopters Dandelion seeds act like little parachutes These seeds and fruits must be light weight

8. Animal Dispersal Some seeds and fruits hitch a ride with an animal Animals eat seeds and excrete seeds elsewhere Burrs and prickles hold onto animal fur

9. Mechanical Dispersal Some plants want to do it on their own Mechanical Dispersal means the seeds fling themselves away from the plant Examples are “touch me nots” and witch hazel

10. Water Dispersal Some plants set sail Waxy coatings make it possible for some fruits to float on water These plants can discover and inhabit new islands