TO DO Label the cross section of the leaf on your worksheet Chloroplast Stoma Lower epidermisAir Spaces Upper epidermisSpongy Mesophyll Cuticle Palisade Mesophyll Guard cells Oxygen Carbon Dioxide

 What does this mean? That they can produce there own energy  Two types of plants Produce seeds eg. Flowering plants Don’t produce seeds eg mosses and ferns  Land plants require??? Water Carbon dioxide Oxygen Sunlight

Shoot system organs above ground: leaves, stems and reproductive organs (flowers and seeds) Root system organs below ground: roots and root hairs

 Plants have specialised cells and tissues for particular roles such as: storage, structure, transport, photosynthesis, respiration, growth and reproduction. Important tissues include 1. Meristematic tissue 2. Dermal tissue including root hairs 3. Ground tissue includes all internal cells except vascular tissue 4. Vascular tissue

 Cells division by mitosis for growth  Found at the root, shoot tips and ring around the inside of stem and branches  Cells differentiate into whatever type of cell/tissue is required.  Allowing Growth in length and width

 is the outer most layer of cells in plant tissues, eg. eipdermis layer Protects the plant body from cuts, invasion by microorganisms and water loss.  Epidermal tissues include: Waxy cuticle on leaves for protection Fine hairs on roots for water absorption

 Internal plant cells (under the epidermal cells) other than the vascular tissue Storage – starch Support Photosynthetic

Transport of substances throughout plant  Two main types: xylem and phloem

 transports water and nutrients from roots to the rest of the plant  in one direction only (roots to leaves)  mature cells are dead and have open ends to conduct water ‘tubular skeletons’

 Transports sugars (sucrose) and other materials from leaves to other parts of the plant  Phloem cells are living  Two types of phloem cells: sieve cells and companion cells Sieve cells  no nucleus  share cytoplasm  pass materials between sieve cells through sieve plates Companion cells  have a nucleus and cell organelles to control each sieve cell

Sucrose enters phloem throughcompanion cell sieve cell diffusion. Water enters phloem from xylem through osmosis

 What are the four different types of tissues found in plants?  What do each do?  Create a table to compare xylem and phloem.

Root system  Anchoring  Uptake of water and nutrients  Fine root hairs increase surface area for more effective uptake

Root pressure  water enters roots by osmosis, dissolved minerals (ions) enter roots by diffusion and active transport  the pressure of osmosis, diffusion and active transport forces water and mineral ions into and up the xylem cells Shoot system  Water moves up through xylem cells, sugars move down through phloem cells  Xylem and phloem cells are found together in vascular bundles  Vascular bundles are arranged differently in each section of the plant

 Continuous upwards movement of water is driven by the evaporation of water from the leaves  The constant loss of water by plants through leaves is called transpiration  The upward movement of water is aided by: Adhesion; attraction between water molecules and the inside walls of xylem vessels Cohesion; forces of attraction between individual water molecules

 The movement of glucose from where it is synthesised (photosynthesis in leaves) to other parts of the plant

Explain the forces that enable water in a xylem vessel to reach the top of a tree?

 Stomata control the movement of carbon dioxide in and water and oxygen out of leaves.  Stomata are tiny pores found mostly in the lower epidermis of leaves  Stoma open when guard cells absorb water and close when they lose water  Stomata open in moist conditions and close in dry conditions, controlling the amount of evaporation

 Through what structure does gas exchange occur in plants?  What is the function of the stomata?  Draw a diagram to show how the stomata open and close  Under what environmental conditions are stomata most likely to be open?  How do stems and roots exchange gases with the environment?

 Deciduous plants: leaves before autumn  Into bark that will peel or drop off  Dead cells to form lignin (woody centre)  Exude resins, fats, waxes or latex