Photosynthesis Worksheet — KS3 — Intermediate
Photosynthesis worksheet for Key Stage 3 / Year 7-9 (Ages 11-14). Intermediate level science practice, aligned to the UK National Curriculum. Print-ready with answer key included.
Exploring Photosynthesis: Understanding the Process
Key Stage 3 / Ages 11-14 / Intermediate Level
Instructions: This worksheet will guide you through the fascinating process of photosynthesis. You will explore the stages of photosynthesis, analyse data related to plant growth, and apply your knowledge through various activities. Ensure you read each question carefully and provide detailed answers where required.
Photosynthesis Equation Completion
Complete the chemical equation for photosynthesis by filling in the missing components. Write the full equation in the box provided.
Fill in the blanks to complete the photosynthesis equation:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6___ + 6___
Stages of Photosynthesis
List and describe the two main stages of photosynthesis. Explain what occurs during each stage and why they are important for the plant.
1. Stage 1:
2. Stage 2:
Photosynthesis Data Analysis
Analyse the data in the table below and answer the questions that follow. Consider how different factors affect the rate of photosynthesis.
| Light Intensity | CO₂ Concentration | Temperature | Rate of Photosynthesis |
| Low | Low | 15°C | Slow |
| High | Low | 25°C | Moderate |
| High | High | 35°C | Fast |
1. Which condition resulted in the fastest rate of photosynthesis?
2. How does light intensity affect the rate of photosynthesis?
3. What might happen if the temperature is too high?
Chlorophyll's Role
Explain the role of chlorophyll in photosynthesis and why it is crucial for the process. Provide examples of how chlorophyll affects plant health.
Describe the role of chlorophyll in photosynthesis.
Photosynthesis Word Search
Find and circle the words related to photosynthesis in the word search. Use the list of words provided to guide you.
| C | C | G | I | F | B | C | A | K | N |
| M | Z | S | V | Y | O | C | S | O | N |
| X | C | B | G | U | I | T | K | N | O |
| F | U | M | E | L | R | V | Y | E | B |
| N | A | Q | A | N | U | S | B | M | R |
| Y | E | E | B | O | E | C | W | C | A |
| V | J | G | L | O | D | R | O | H | C |
| W | A | U | Y | Y | L | P | G | S | Z |
| K | A | A | F | X | E | J | T | Y | E |
| H | G | Y | I | R | O | X | H | B | N |
[ ] PHOTOSYNTHESIS [ ] CHLOROPHYLL [ ] GLUCOSE [ ] OXYGEN [ ] CARBON [ ] ENERGY
Photosynthesis and Environment
Discuss how photosynthesis impacts the environment and contributes to the global carbon cycle. Use specific examples to illustrate your points.
Explain the environmental impact of photosynthesis.
Photosynthesis True or False
Read each statement about photosynthesis and determine whether it is true or false. Write your answer in the box provided.
1. Photosynthesis occurs in the mitochondria.
2. Oxygen is a byproduct of photosynthesis.
3. Photosynthesis requires sunlight.
4. Carbon dioxide is absorbed by plants during photosynthesis.
Photosynthesis Diagram Labelling
Label the parts of the leaf involved in photosynthesis using the diagram provided. Use the labels from the word bank to fill in the blanks.
Word Bank
Activity 1: O₂ ; H₂O
Activity 2: Light-dependent reactions ; Calvin cycle
Activity 3: High light intensity, high CO₂ concentration, 35°C ; Increases rate ; Enzyme denaturation
Activity 4: Chlorophyll absorbs light energy for photosynthesis
Activity 5: Word search puzzle
Activity 6: Balances oxygen and carbon dioxide levels
Activity 7: False ; True ; True ; True
Activity 8: Diagram labelling with correct parts
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