A toxic substance is one which is poisonous to organisms.

An increase in the concentration of a chemical within an organism is called bioaccumulation.

Pesticides are chemicals that are used to control pests (organisms that compete with humans for food supplies).

Bioaccumulation

Science

Pupils will move on to construct and interpret pyramids of number and biomass from food chains data. Pupils will learn about how plants and animals are adapted to survive and the impact of changes to the environment on biodiversity. The importance of biodiversity and the importance of gene banks. How to sample plant and animal populations to aid our understanding and monitoring of populations. 

In Y4 pupils learnt about their local environment and to recognise that environments can change. Pupils also explored examples of human impact (both positive and negative) on environments. Pupils looked at a variety of food chains to identify producers, predators and prey.

Ecosystems

a chemical which kills organisms that might eat or damage a crop

a chemical which kills plants. They are sometimes called weedkillers

Match the words with their correct meanings.

Toxic chemicals can build up in organisms in a food chain. This is known as ...

Look at the food web diagram. Which of the organisms would be killed by a herbicide?

Look at the food web diagram. How many organisms would be killed directly by an insecticide?

Look at the food chain diagram. Which of the organisms is most likely to build up toxic levels of insecticide in their bodies?

Look at the woodland food web. Which of the following organisms is an apex predator?

Look at the woodland food web. Which of the following organisms is a producer?

both the living organisms and non-living parts of an area.

Look at the food chain diagram. What things will happen if the deer die out?

Farmers use chemicals to help them produce enough food for the human population. Having enough food for the human population is called...

Chemicals which kill pests are called ...

Starter Quiz