Plant tissues

Cross section of plant

Waxy cuticle, upper epidermis, palisade mesophyll layer, spongy mesophyll layer, xylem and phloem and lower epidermis

Waxy cuticle

Prevents loss of water by evaporation

Transparent to allow light for photosynthesis

Upper epidermis

Protects surface of leaf

Transparent to allow light for photosynthesis

Palisade mesophyll

Contains palisade cells full of chloroplasts that require light energy for photosynthesis

Spongy mesophyll layer

Contains large air pockets for carbon dioxide to diffuse into palisade cells and oxygen to diffuse out

Xylem

Transports water for photosynthesis and mineral ions

Travels in ONE DIRECTION

Phloem

Transports dissolved sugars made by photosynthesis to the rest of the plant (translocation)

Lower epidermis

Contains stomata, protects leaf

Stomata

Tiny pores which allow carbon dioxide to enter the leaf and oxygen to exit it

Found on underside of plant evaporation will be reduced, and reduces exposure to heat and air current

Transpiration

Rate of transpiration

Higher temp = inc in transpiration

Faster under dry conditions when not humid bc evaporation happens quicker when dry

Increases with wind - water vapour constantly moved away

Increases with light intensity = more photosynthesis