Living things and classification
What all living things do, sorting living things into groups by their features, and using keys to identify them.
📌 Key points
- All living things carry out seven life processes: movement, respiration, sensitivity, growth, reproduction, excretion and nutrition (MRS GREN).
- Scientists classify (sort) living things into groups by their features, e.g. plants, animals, fungi and microorganisms.
- Vertebrates have a backbone. The five groups are fish, amphibians, reptiles, birds and mammals.
- Invertebrates have no backbone, e.g. insects, spiders, worms, snails and jellyfish.
- Mammals have hair or fur and feed their young on milk. Birds have feathers and lay eggs with hard shells.
- Reptiles have dry, scaly skin. Amphibians have moist skin and lay their eggs in water. Fish have scales and breathe with gills.
- Insects have 6 legs and 3 body parts. Spiders have 8 legs and 2 body parts.
- A key uses questions about features to help you identify a living thing.
- Microorganisms are living things too small to see without a microscope. Some are helpful (yeast makes bread rise) and some cause disease.
📖 Key words
- Classify
- To sort things into groups by their features.
- Vertebrate
- An animal with a backbone.
- Invertebrate
- An animal without a backbone.
- Key
- A set of questions used to identify a living thing.
- Species
- A group of very similar living things that can breed together.
- Microorganism
- A living thing too small to see without a microscope, such as bacteria.
- Respiration
- The process in living cells that releases energy from food.
✏️ Worked example
An animal has no backbone, 8 legs and 2 body parts. Use the key to identify its group.
1. Does it have a backbone? Yes: vertebrate. No: go to 2.
2. Does it have 6 legs? Yes: insect. No: go to 3.
3. Does it have 8 legs? Yes: spider. No: other invertebrate.
- Question 1: it has no backbone, so go to question 2.
- Question 2: it does not have 6 legs, so go to question 3.
- Question 3: it has 8 legs, so it is a spider.
- Answer: it is a spider, which is an invertebrate.
Follow a key one question at a time, and only use the feature that each question asks about.
Test yourself8 questions from a bank of 22. A new mix every time.
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