Plant Tissues and Organ Systems

Plants, like animals, are organised into cells, tissues, organs and organ systems. For AQA GCSE Biology, you need to understand the key plant tissues (epidermal, palisade mesophyll, spongy mesophyll, xylem, phloem and meristem), how they combine to form plant organs (roots, stems and leaves), and how the leaf in particular is adapted for photosynthesis. This lesson covers all of these areas in detail.

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Plant Organs

The three main organs in a plant are the root, the stem and the leaf. Each has a specific role:

Organ	Main Functions
Root	Absorbs water and mineral ions from the soil; anchors the plant in the ground; stores food (e.g. in carrots, potatoes)
Stem	Supports the plant and holds leaves up towards the light; transports water, minerals and sugars between roots and leaves via xylem and phloem
Leaf	Main site of photosynthesis; also the site of gas exchange and transpiration (water loss)

Other plant organs include flowers (reproduction) and fruits (seed dispersal).

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Plant Tissues

Plants have several specialised tissues. You need to know the following:

Epidermal Tissue