Life Processes in Plants - Class 7 Science (CBSE)
Based on the 2026-27 Class 7 Science syllabus for the NCERT-aligned book Curiosity. Use these notes to understand, observe, explain, and answer in full sentences.
1. Why this chapter matters
Plants are living organisms that make food, exchange gases, transport substances, and respire. Their leaves, roots, stems, and vascular tissues work together.
This chapter is not meant for rote learning. Read every idea with an example, then ask: what can I observe, test, draw, measure, or explain?
2. Core ideas
Photosynthesis
Green plants make food using carbon dioxide, water, sunlight, and chlorophyll. Oxygen is released as a by-product.
Leaves and stomata
Leaves contain chlorophyll and stomata. Stomata allow gas exchange but also cause water loss, so plants regulate them.
Transport in plants
Xylem carries water and minerals upward. Phloem transports prepared food to different parts of the plant.
3. Key points to remember
- Observation: Record what is actually seen, measured, or compared.
- Fair test: Change one factor and keep other factors the same.
- Conclusion: Use evidence to answer the question.
- Scientific vocabulary: Use precise terms from the chapter.
4. Worked examples
Example 1: Why is sunlight needed for photosynthesis?
Light energy drives the process of making glucose from carbon dioxide and water.
Example 2: What does iodine test show in a leaf?
Iodine turns blue-black in the presence of starch, showing food formation.
Example 3: Why do roots matter for photosynthesis?
Roots absorb water and minerals needed by the plant.
Example 4: Do plants respire?
Yes. Plants respire to release energy from food.
5. Activity and observation
Use the iodine test on a destarched leaf exposed to sunlight. A blue-black colour shows starch formation.
Write the activity in this format:
- Aim: What are you trying to find out?
- Materials: What did you use?
- Procedure: What steps did you follow?
- Observation: What did you see or measure?
- Conclusion: What scientific idea does it prove?
6. Common mistakes
- Writing only definitions without examples.
- Drawing diagrams without labels.
- Confusing observation with conclusion.
- Ignoring units in speed, time, distance, temperature, or measurement questions.
- Giving unsafe suggestions for experiments instead of classroom-safe methods.
7. Practice set
- Define the main idea of Life Processes in Plants.
- Write two key terms from this chapter and explain them.
- Describe one activity that proves an idea from this chapter.
- Give one real-life application of photosynthesis.
- Write one difference-based question from this chapter.
- How can you make your answer more scientific?
8. Answer key
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Define the main idea of Life Processes in Plants. Answer: Plants are living organisms that make food, exchange gases, transport substances, and respire. Their leaves, roots, stems, and vascular tissues work together.
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Write two key terms from this chapter and explain them. Answer: photosynthesis and chlorophyll are central terms. Define each with one example from daily life.
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Describe one activity that proves an idea from this chapter. Answer: Use the iodine test on a destarched leaf exposed to sunlight. A blue-black colour shows starch formation.
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Give one real-life application of photosynthesis. Answer: Use the chapter idea to explain a daily event, then name the observation that supports your answer.
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Write one difference-based question from this chapter. Answer: Compare two related ideas, such as Photosynthesis and Leaves and stomata, using meaning and example.
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How can you make your answer more scientific? Answer: Use observation, correct vocabulary, labelled diagrams or tables, and a clear reason.
9. Quick revision
- Main themes: photosynthesis, chlorophyll, stomata, transport, plant respiration.
- Learn definitions with examples.
- Practise one diagram, table, or activity.
- Revise the worked examples.
- Write answers using cause, evidence, and conclusion.
