IT’S A GREEN WORLD Who planted that there?

Starter Would a plant survive if it had a mutation of: Leaves with only a red pigment Leaves like footballs Leaves with no stomata

Who planted that there? Learning outcomes Success criteria Describe the entry and exit points of materials required for photosynthesis. Explain how leaves are adapted for efficient photosynthesis. Be able to design different types of leaves, demonstrating their adaptations for particular environmental conditions

Photosynthesis - Brainpop.swf

Photosynthesis: word equation light energy carbon dioxide water glucose oxygen chlorophyll light energy chlorophyll carbon dioxide oxygen Students to copy word equation glucose water

Photosynthesis Carbon dioxide enters and oxygen leaves the leaf through small pores on the underside of the leaf – stomata. Water enter the plant through the root hairs. Glucose is stored by the plant as starch

Testing leaves for starch – procedure This four-stage virtual experiment demonstrates how iodine can be used to test for starch. It could be used as a precursor to running the practical in the lab, or as a revision exercise. Suitable prompts include: Stage 1: Why is the leaf placed in boiling water? Stage 2: What does the warm alcohol do to the leaf? Stage 3: Why is the leaf placed in warm water? Stage 4: What colour change occurs if starch is present?

Leaves: maximizing photosynthesis Leaves are the most efficient solar panels on Earth! Why can they be called this? Light energy is absorbed by the chlorophyll in leaves and used to carry out photosynthesis. Leaves come in all shapes and sizes but what features do they have in common to maximize photosynthesis?

Structure of a leaf How are leaves designed to maximize photosynthesis? Leaves are wide and flat to create a large surface area and to absorb as much light as possible. Leaves are thin so gases can reach cells easily. Leaves contain lots of chloroplasts which contain the green pigment chlorophyll. Students to take notes Leaves have holes, called stomata, on their underside through which gases move in and out. Leaves have lots of veins to carry water to the cells and carry glucose away.

Autumn leaves Leaves on deciduous trees change colour in autumn because the trees absorb the green pigment from the chloroplasts. Because leaves are specially adapted to carry out photosynthesis many cannot survive winter frosts and drop off the trees.

Although leaves do the same basic job, they also have to adapt to their environment and balance a range of needs.

Designing leaves Label them with explanations. withstand strong winds live in fast-flowing rivers live in a shady environment live in a hot dry environment Label them with explanations. Construct a palisade cell out of plasticine

Plenary

Who planted that there? Learning outcomes Success criteria Describe the entry and exit points of materials required for photosynthesis. Explain how leaves are adapted for efficient photosynthesis. Be able to design different types of leaves, demonstrating their adaptations for particular environmental conditions