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lesson 3 ch.5
1st period lesson 5 chapter 3
| Term | Definition |
|---|---|
| Tropism | A plants growth response toward or away from a stimulus. |
| Hormone | chemical that affects how the plants grows and develops |
| Photoperiodism | Plants response to seasonal changes in the length of night and day |
| Critical night length | Number of hours of darkness that determines whether or not a plant will flower. |
| Dormancy | A period when an organisms growth or activity stops. |
| 3 stimuli that produce plant responses | Gravity, light and touch |
| example of positive and negative tropism | Stems, leaves and flowers growing toward light is positive, roots that grow away from light are negative tropism. |
| What triggers plant to flower | the amount of darkness a plant receives determines the time of flowering in many plants. |
| Why is dormancy important | It helps plants survive freezing temperatures and the lack of liquid water. |