Leaves Flashcards
Stomata -
Allows gases to diffuse into and out of the leaf
Waxy layer
Reduces amount of water evaporating
Guard cells
Open and close stomata
Veins
Transport water to cells in leaf
Cells in palisade layer
Main site of photosynthesis
Suggest why stomata may close during hot weather
To prevent water evaporating
How are leaves adapted for photosynthesis
Green - contains chlorophyll absorbs sunlight
Thin - allows gases to diffuse in and out easily
Large surface area- Absorb as much light as possible
Veins - Contain xylem tubes which transport water and phloem tubes which transport glucose
Why is the bottom of the leaf lighter than the top
The bottom contains fewer chloroplasts which means there is less chlorophyll. Most sunlight needs to hit the top so it needs to absorb the most sunlight it can
Why is the top layer waxy
The sun will heat up top. The waxy layer reduces the amount of water evaporating out of this part of the leaf
How do gases diffuse in and out of the leaf
Allows gases to diffuse in and out of the tiny holes in the stomata
Carbon dioxide diffuses in
Oxygen and water vapour diffuses out
Stomata open and close due to guard cells
Open during day close at night
Palisade layer
Cells packed with chloroplasts
Most photosynthesis occurs
Spongy layer
Contains air spaces allowing carbon dioxide to diffuse in and oxygen to diffuse out
