Characteristics of Living Things

When you look at the world around you, how do you categorise or group what you see? One of the broadest groupings is 'living' and 'non-living'. This may sound simple, but it is sometimes difficult to decide whether something is truly alive or not. Here we look at the characteristics of living things – using earthworms as an example.

Further classification

Based on this information, we can confidently categorise earthworms as living things as they carry out all seven life processes.

It is now possible to classify them further into a series of hierarchical categories: kingdom, phylum, class, order, family, genus and species. Classifying living things into these categories is an important way for scientists to show how living things are related to each other. Most scientists classify living things into one of the following six kingdoms.

• Bacteria are single-celled microorganisms that don’t have a nuclear membrane.
• Protozoans are single-celled organisms that are generally much larger than bacteria. They may be autotrophic or heterotrophic.
• Chromists are a diverse group of plant-like organisms and range from very small to very large. They are found in almost all environments.
• Fungi are multicellular and rely on breaking down organic material as they are not able to make their own food.
• Plants are multicellular and autotrophic – they use photosynthesis to produce food using sunlight.
• Animals are multicellular. They are heterotrophic and rely on other organisms for food.