LEAF STRUCTURE Flashcards
1
Q
Wax cuticle
A
Top layer
Prevents water from evaporating
2
Q
Upper epidermis
A
Thin and transparent to allow light to enter palisade mesophyll layer
3
Q
Palisade mesophyll
A
packed with chloroplasts to absorb more light, maximising photosynthesis
4
Q
Spongy mesophyll
A
Contains air spaces which increase the surface area to volume ratio for diffusion of gases.
5
Q
Lower epidermis
A
Contains guard cells and stomata
6
Q
Guard cell
A
Opens and closes the stomata
- to allow CO2 to diffuse in, O2 to diffuse out
7
Q
Stomata
A
Where gas exchange takes place.
Opens during the day n closes during night
8
Q
Vascular bundle
A
Contains xylem n phloem to transport substances to and from the leaf
9
Q
Xylem
A
Transports water and dissolved minerals
- walls thickened w lignin
- cells are DEAD, allows free passage of water
- No top n bottom wall
- xylem uses transpiration i think
10
Q
Phloem
A
Transports sucrose and amino acids around the plant
- made of LIVING CELLS
- cells are joined end to end n have holes in the end cell walls to flow easily though the translocaition….
