B4c-Leaves and photosynthesis Flashcards
1
Q
Why arent chloroplasts found in all plant cells?
A
They contain pigments that absorb light energy, so are not found in root cells which are not exposed to light
2
Q
Name parts of a leaf
A
- Cuticle
- upper and lower epidermis
- palisade and spongy mesophyll layer
- stomata and guard cells
- vascular bundle
3
Q
How is a leafs cellular structure adapted for photosynthesis?
A
- epidermis is transparent (light can pass through it to palisade layer)
- palisade layer at top contains most of chloroplasts (get most light)
- air spaces in spongy mesophyll layer allow diffusion between stomata and photosynthesising cells
- internal surface area to volume ratio is very large(large area for gas excchange)
4
Q
Where does water enter?
A
Through root hairs
5
Q
Where does carbon dioxide enter?
A
Through stomata
6
Q
Where does oxygen exit?
A
Through stomata
7
Q
How are leaves adapted for efficient photosynthesis?
A
- broad, large surface area for gases to diffuse
- thin, short distance for gases to diffuse
- contain chlorophyll and other pigments to absorb light from different parts of the spectrum
- network of vascular bundles for support and transport
- guard cells which open and close the stomata
8
Q
How do plants maximise the use of energu from the sun?
A
They contain different pigments which absorb different wavelengths of light
9
Q
What are the four pigments?
A
- chlorophyll a
- chlorophyll b
- carotene
- Xanthophyll
