Plant cell organisation Flashcards
Plants are made of
stems, roots and leaves. Plants organs work together to make organ systems. These can perform the various tasks that a plant needs to carry out to survive and grow - for example, transporting substances around the plants.
Plants organs are made of tissues . Examples of plant tissues are :
1) Epidermal tissue - this covers the whole plant
2) Palisade mesophyll tissue - this is the part of the leaf where most photosynthesis happens
3) Spongy mesophyll tissue - this is also in the leaf, and contains big air spaces to allow gases to diffuse in and out of cells
4) Xylem and phloem - they transport things like water, mineral ions and food around the plants
5) meristem tissue - this is found at the growing tips of shoots and roots and is able to differentiate into lots of diff types of plant cell, allowing the plant to grow
leaves contain
epidermal, mesophyll, xylem and phloem tissues
Structure of leaves and how they relate to function
1) The epidermal tissue are covered with a waxy cuticle, which helps to reduce water loss by evaporation
2) The upper epidermal is transparent so that light can pass through it to the palisade layer
3) The palisade layer has lots of chloroplast .This means that they’re near the top of the leaf where they can get the most light
4) The xylem and phloem form a network of vascular bundles, which deliver water and other nutrients to the entire leaf and take away the glucose produced by photosynthesis. They also help support the structure.
5) The tissues of the leaves are also adapted for efficient gas exchange. E.g. the lower epidermal if full of stomata (lh) is controlled by guard cells in response to environmental conditions. The airspaces in the spongy mesophyll tissue increases the rate of diffusion of gases.
