* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Leaves and Photosynthesis
Survey
Document related concepts
Extracellular matrix wikipedia , lookup
Cell membrane wikipedia , lookup
Cell nucleus wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell growth wikipedia , lookup
Cell culture wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Cytokinesis wikipedia , lookup
Endomembrane system wikipedia , lookup
Transcript
Leaves and Photosynthesis • What adaptations do leaves have for photosynthesis? Plant cell cell wall cell membrane cytoplasm nucleus vacuole chloroplast Name the structure… Function Structure Controls what goes in and out of the cell. Contains the genetic material. cell membrane Surrounds the cell and gives support. cell wall Contains chlorophyll and absorbs sunlight. Contains cell sap and gives support. Where all the chemical reactions happen. nucleus chloroplasts vacuole cytoplasm Chloroplasts absorb sunlight External: How leaves are adapted for efficient photosynthesis Side vein Apex Mid-rib vein Leaf stalk (petiole) Leaf blade (lamina) Draw this table in your books Feature of leaves Broad, flat leaves Stomata Veins Chloroplasts Waxy layer Thin How it aids photosynthesis How leaves are suited to photosynthesis • Leaves are broad and flat, giving large surface area to absorb as much light as possible. They have ‘holes’ in the leaves to allow carbon dioxide in and oxygen out. These are STOMATA. Stoma Guard cells There are veins in the leaves to transport water and sugar around. Many of the cells are packed with chloroplasts which contain a light trapping pigment- chlorophyll. There is a waxy layer on top to stop water being lost from the leaf. Thin leaves provide a short diffusion distance for carbon dioxide to reach the palisade and mesophyll cells HT: How structure of the leaf is adapted for efficient photosynthesis • Epidermis is transparent; • Palisade layer at the top containing most of the chloroplasts; • Air spaces in the spongy mesophyll allow diffusion between stomata and photosynthesising cells; • Internal surface area / volume ratio very large. Leaf cross section • In pairs examine a slide of FT: Plenary • Use what you now know about leaves and photosynthesis to design an ‘ideal leaf’ that will maximise photosynthesis • Draw and label your leaf to explain how it is adapted to be more efficient (You may want to include the external environment it would be found in e.g. A desert or rainforest) HT: Plenary Questions • Draw this diagram of a Marram grass leaf. Marram grass is found on sand dunes. 1) What does the waxy cuticle do? 2) How does the position of the stomata help this plant? 3) Why are there no stomata on the outer surface of the leaf? 4) Explain the function of the hairs on the inner surface of the leaves? 5) Explain how having sunken stomata will affect gaseous exchange in the plant, and why this would be an advantage to the plant.