| A | B |
|---|
| stomata | the actual opening on the underside of a leaf; used to control the amount of water in a plant. |
| guard cell | one of a pair of cells used to control the size of the stoma |
| transpiration | the process of water exiting from a plant through the stomata of leaves |
| palisade layer | the layer of tightly packed cells underneath the epidermis of a leaf |
| spongy layer | the layer of loosely packed cells above the lower epidermis of a leaf |
| hormone | chemical produced by plants to control growth function |
| tropism | a plant's response to the enviroment |
| phototropism | a plant's response to light |
| gravitropism | a plant's response to gravity |
| photoperiodism | a plant's response to the length of day |
| long-day | plants which bloom when days are long and nights are short |
| short day | plants which bloom when days are short and nights are long |
| day neutral | plants which bloom based on conditions other than day length |
| positive tropism | a response toward a stimulus |
| negative tropism | a response away from a stumulus |
