Plant Growth (Light and Water) - Teacher Explanation

Welcome to Lesson 3.18 on 'How Light and Water Affect Plant Growth' for Year 3 students, as part of the Plants unit. This lesson aligns with the National Curriculum, which outlines the necessity for pupils to investigate what plants require for life and growth. These essentials include air, light, water, nutrients, and space, and can vary between different plant species. It's important to be mindful of any students with plant allergies, as they will be handling plant matter. After the activities, all pupils should wash their hands thoroughly. The lesson also offers opportunities for cross-curricular learning; students can draw graphs to represent their findings in maths or compose a song about photosynthesis in English.

The teacher demonstration aims to show that plants absorb something from the air, specifically carbon dioxide, which is critical for photosynthesis. This process allows plants to produce glucose and oxygen using carbon dioxide, water, and sunlight. For the demonstration, you'll need broad leaves, such as lily leaves, plastic bottles, cups, straws, and calcium hydroxide to create lime water, which is used to detect carbon dioxide. The experiment involves blowing into the lime water to show the presence of carbon dioxide and then demonstrating how plants remove carbon dioxide from the air. This sets the stage for the pupils' experiments on the effects of light and different liquids on plant growth, using materials like coloured cellophane, foil, plant pots, and various seeds. Pupils will explore how different conditions affect plant growth, engaging in scientific inquiry and analysis.