Question | Answer |
What is the role of phloem? | To transport sugars from leaves around the plant |
What is the role of xylem? | To transport water from roots up the plant |
What is transpiration? | process by which water is pulled up the plant |
Why do plants need water? | for light dependent stage of photosynthesis |
Which factors increase the rate of transpiration? | increased temperature, increased wind, lower humidity |
What strengthens xylem? | rings of lignin |
What cells help phloem survive? | companion cells |
what is the role of waxy cuticle on a leaf? | prevents water loss |
what is the role of epidermis in a leaf? | protection |
what is the role of mesophyll in a leaf? | it is where most of photosynthesis occurs. |
what are two types of mesophyll? | palisade and spongy |
what are stomata? | holes where gas exchange occurs in lower epidermis of leaves |
what are guard cells? | cells that control opening and closing of stomata |
how do stomata open? | water enters the guard cells by osmosis (they become turgid) and stomata opens |
how do stomata close? | water leaves the guard cell by osmosis (they become plasmolysed) and stomata close |
How does transpiration work? | water evaporates through open stomata which draws more water up from roots |
What plant cells absorb water from the soil? | root hair cells |
How are root hair cells adapted to absorbing water? | they have a large surface area. |
what gas enters the leaves through stomata? | carbon dioxide |
Why does carbon dioxide need to enter leaves? | to be used in carbon fixation stage of photosynthesis |
What gas leaves the leaves through stomata? | oxygen |
Where does the oxygen that leaves leaves come from? | it is a byproduct of light dependent reaction in photosynthesis |
Are stomata open during the day or at night? | stomata are open during the day |
Are stomata closed during the day or at night? | stomata are closed during the night |
Why are stomata open during the day? | when there is light plant needs to be able to do gas exchange for photosynthesis |
why are stomata closed during the night? | there is no light so photosynthesis does not occur, stomata are closed to conserve water |