plants

3. The young plant that develops from the zygote, or fertilized egg, is called the
7. touch, gravity, and light are three important stimuli that that trigger growth in plants
8. fertilized egg is called a
11. is the number of hours of darkness that determines whether or not a plant will flower
12. protects the seeds as they develop
13. keeps the plant from injury when it grows

1. Next is a layer of cells called the
2. plant's response to seasonal changes in the length of night and day is called a
4. carries substances between the plant's roots
5. occurs when a sperm cell unites with an egg cell
6. helps plants survive freezing temperatures and lack of liquid water
9. open and close to control when gases enters and leaves the leaf, and oxygen and water vapor exit
10. is on the plant that has color