| A | B |
|---|
| stromata | openings between guard cells of a leaf |
| guard cell | one of the cells that surround a stroma and control the opening and closing of the stroma |
| transpiration | the release of water from leaves through stromata |
| palisade layer | the leaf tissue that consists of closely packed, tall thin cells that carry on the majority of the photosynthesis |
| spongy layer | the leaf tissue consisting of loosely packed cells that carry on photosynthesis, has air space between the cells |
| hormone | a chemical produced by living cells and transported to other body tissues where it causes a specific effect |
| tropism | The growth of plants in response to external stimuli such as light, gravity or contact. |
| phototropism | the growth of a plant part in a certain direction in response to light |
| gravitropism | the growth of a plant part in a certain direction in response to gravity |
| photoperiodism | the response of a plant to changes in the length of daylight and night |
