Plant Cell Oganisation

Plat tissues:

1) Epidermal tissues- covers the whole plant.

2) Palisade mesophyll tissue- where most of the photosynthesis happens.

3) Songy mesophyll tissue- contains big air spaces to allow gases to diffuse in and out of cells.

4) Xylem and phloem- transports water and food (sugar) around the plant.

5) Meristem tissue- found in the growing tips of shoots and is able to differentiate to allow the plant to grow.

Structures and their function in a leaf:

• Epidermal tissue is covered in a waxy cuticle which reduces water loss be evaporation.
• Upper epidermis is transparent so light can pass through into the palsade layer.
• Palisade layer contains lots of chloroplasts (contain chlorophyll which slows down light so it can be used in photosynthesis) and is at the top of the leaf to get the most light.
• Xylem and Phloem form a vascular network which deliver water and other neutrients, and takes away glucose produced by photosynthesis. They also help support the structure of the leaf.
• The tissues on the leaf are adapted for gas exchange:
• the lower epidermis is full of stomata (little holes) which let CO diffuse directly into the leaf. Guard cells either side if a stomata control the opening and closing in response to enviromental conditions.
• the air spaces in the spongy mesophyll increase the rate of diffusion by providing room for water molecules to move. 

Phloem tubes transport food:

Made of elongated living cells with small pores in the end walls to allow cell sap to flow through. Transports food mainly dissolved…