KO: Microorganisms
Subject: Science | Year: 6
Name: _________________________ Class/Set: ____________ Date: ____________
1. Key Knowledge / Core Facts
- Microscopic: Organisms so small they can only be seen using a microscope.
- Classification: Microorganisms are their own kingdom, separate from larger plants and animals.
- Groups: Five main types exist: Bacteria, Viruses, Fungi, Algae, and Protozoa.
- Habitats: Microorganisms live almost everywhere, including in soil, water, air, and inside the human body.
- Growth: Most microorganisms require warmth, moisture, and a food source (nutrients) to multiply.
- Population: One single bacterium can multiply into millions in less than half a day under the right conditions.
2. Key Vocabulary
- Microorganism: A living thing that is too small to see without magnification.
- Pathogen: A harmful microorganism that causes disease or infection.
- Decomposition: The process where fungi and bacteria break down dead matter, recycling nutrients into the soil.
- Fermentation: A chemical process where microorganisms (like yeast) break down sugars into alcohol or acids and CO₂.
- Antibiotic: Medicine (like Penicillin) used to kill harmful bacteria inside the body.
- Vaccination: A treatment that helps the body’s immune system recognise and fight specific pathogens.
3. Helpful Microorganisms
- Yeast: A fungus used in baking; it consumes sugar and breathes out Carbon Dioxide (CO₂), making bread rise.
- Gut Bacteria: Millions of 'friendly' bacteria in the human digestive system help break down food and produce vitamins.
- Food Production: Specific bacteria are used to turn milk into yoghurt and cheese.
- Medicine: Some fungi, such as Penicillium, are used to create life-saving antibiotics.
- Waste Management: Microorganisms are essential in sewage works to break down human waste and clean water.
4. Harmful Microorganisms
- Viruses: The smallest type of microorganism; causes illnesses like the common cold, flu, and chickenpox.
- Bacteria: Can cause infections like food poisoning (Salmonella) or throat infections.
- Fungi (Mould): Grows on food like bread or fruit, making it rot and become unsafe to eat.
- Tooth Decay: Bacteria in the mouth feed on sugar and produce acid, which dissolves tooth enamel.
- Plague: Historically, bacteria caused devastating diseases like the Black Death.
5. Preventing Spread and Growth
- Handwashing: Using soap and water physically removes pathogens from the skin.
- Refrigeration: Storing food at 5°C or below slows down the rate at which bacteria and mould multiply.
- Freezing: Stops the growth of microorganisms entirely, though it does not always kill them.
- Cooking: Heating food to high temperatures (above 70°C) kills most harmful bacteria.
- Antiseptics: Chemicals used on surfaces or skin to destroy microorganisms.
6. Working Scientifically
- Observation: Using magnifying glasses or microscopes to identify different structures in fungi.
- Variables: In a mould growth experiment, the Independent Variable might be the temperature (e.g., fridge vs. cupboard).
- Controlled Variables: To ensure a fair test, keep the type of bread and the amount of moisture the same.
- Safety: Never open a sealed container or bag containing growing mould, as spores can cause respiratory issues.
- Data: Recording the surface area of mould growth over time using a centimetre grid.
⚠ TEACHER’S GUIDANCE
🍎 Pedagogical Overview
- Year Group: Year 6 (KS2).
- Delivery: This Knowledge Organiser (KO) is designed to support the 'Living Things and Their Habitats' unit. It provides the high-density factual 'sticks' needed for retention before moving into experimental work.
- Common Misconceptions:
- "All germs are bad": Students often equate microorganisms only with illness. Emphasise the role of yeast and gut flora to balance this view.
- "Viruses and Bacteria are the same": Clarify that antibiotics only work on bacteria, not viruses.
- Safety Warning: When conducting the 'Mouldy Bread' experiment, ensure all samples are double-bagged and taped shut. Dispose of them without opening to comply with health and safety standards.
💡 Teaching Strategies
- Retrieval Practice: Use the 'Key Vocabulary' section for weekly 'Look, Cover, Write, Check' or low-stakes quizzes.
- Dual Coding: Encourage students to draw simple diagrams of a bacterium, a virus, and a yeast cell next to the 'Groups' bullet point.
- Active Learning: Conduct a 'Glitter Germ' activity to model how easily pathogens spread through touch to support Section 5 (Preventing Spread).