Plants Flashcards
1
Q
What layers are there in a leaf? Give them in order.
A
Waxy cuticle, upper epidermis, pallisade mesophyll, spongy mesophyll, lower epidermis
2
Q
Waxy cuticle
A
- thin layer on the top of the leaf
- waterproof to protect the leaf
3
Q
Upper epidermis
A
- transparent to allow light to pass through
4
Q
Pallisade mesophyll
A
- has lots of chloroplasts —> lots of photosynthesis
- vacuole pushes the chloroplasts to the edges of the cells
5
Q
Spongy mesophyll
A
- air spaces for gas exchange
6
Q
Lower epidermis
A
- stomata: holes in which gases diffuse in and out of (CO2 in, O2 out)
- guard cells: open and close the stomata to prevent transpiration (water loss)
7
Q
What is the job of the xylem?
A
The xylem transports water from the roots to the leaf.
8
Q
What is the job of the phloem?
A
The phloem transports sugar e.g. sucrose around the plant.
9
Q
Features of the xylem
A
- end of cell walls are removed so that water can pass through
- water moves as a continuous column and a suction force pulls it up the stem
- cells are dead (more space for water as there are no mitochondria, cytoplasm)
- lignin: provide strength to withstand water pressure
10
Q
What is the name of the transport process that happens in the xylem?
A
Transpiration stream
11
Q
Features of the phloem
A
- holes between the cells (sieve plates) allow sugars to pass from one cell to another
- has a companion cell whcih provides ATP to load sugars into the phloem
- cells are living
12
Q
What is the name of the transport process that happens in the phloem?
A
Translocation
13
Q
The xylem and phloem are …………… found in groups called ……………….. ……………
A
tissues, vascular bundles
