New
New
Year 7

Bioaccumulation

I can describe how toxic materials can accumulate and affect organisms in a food chain.

New
New
Year 7

Bioaccumulation

I can describe how toxic materials can accumulate and affect organisms in a food chain.

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Lesson details

Key learning points

  1. Some toxic substances are persistent (they stay in the environment and do not break down).
  2. If consumed, persistent toxic substances can be passed up the food chain.
  3. The bioaccumulation of toxic substances can cause damage to organisms, particularly top predators.
  4. The use of pesticides in farming can cause bioaccumulation.

Keywords

  • Toxic - A toxic substance is one which is poisonous to organisms.

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

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

Common misconception

Pupils do often not understand that pesticides can build up within a food chain.

The lesson covers examples of how pesticides can be absorbed into producers and passed along food chains as organisms eat food.

There are a number of videos available that can be used to show how extensively pesticides were used in the UK in the 1950s, and the impact that this had on organisms. Material can be used to discuss the pros and cons of the use of pesticides.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Lesson video

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6 Questions

Q1.
Look at the woodland food web. Which of the following organisms is an apex predator?
An image in a quiz
Chiff chaff
Vole
Blue tit
Correct answer: Stoat
Q2.
Look at the woodland food web. Which of the following organisms is a producer?
An image in a quiz
Blue tit
Aphid
Lady bird
Correct answer: Bramble
Q3.
An ecosystem includes...
only the living organisms in an area.
only the non-living parts of an area.
Correct answer: both the living organisms and non-living parts of an area.
Q4.
Look at the food chain diagram. What things will happen if the deer die out?
An image in a quiz
The tigers will start to eat the grass
The population of grass will decrease
Correct answer: The population of grass will increase
Correct answer: The population of tigers will decrease
Q5.
Farmers use chemicals to help them produce enough food for the human population. Having enough food for the human population is called...
Correct answer: food security.
a food bank.
food shortage.
a food hamper.
Q6.
Chemicals which kill pests are called ...
Correct Answer: pesticides, pesticide

6 Questions

Q1.
What does the hazard symbol mean?
An image in a quiz
Corrosive
Correct answer: Toxic
Hazardous
Corrosive
Irritant
Q2.
Match the words with their correct meanings.
Correct Answer:Pesticide,a chemical which kills organisms that might eat or damage a crop

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

Correct Answer:Herbicide,a chemical which kills plants. They are sometimes called weedkillers

a chemical which kills plants. They are sometimes called weedkillers

Correct Answer:Insecticide,a chemical which kills insects

a chemical which kills insects

Correct Answer:Fungicide,a chemical which kills moulds

a chemical which kills moulds

Q3.
Toxic chemicals can build up in organisms in a food chain. This is known as ...
Correct answer: bioaccumulation
excretion
pollution
magnification
Q4.
Look at the food web diagram. Which of the organisms would be killed by a herbicide?
An image in a quiz
Vole
Moth larva
Correct answer: Bramble
Ladybird
Q5.
Look at the food web diagram. How many organisms would be killed directly by an insecticide?
An image in a quiz
1
2
Correct answer: 3
4
5
Q6.
Look at the food chain diagram. Which of the organisms is most likely to build up toxic levels of insecticide in their bodies?
An image in a quiz
Organism A
Organism B
Organism C
Correct answer: Organism D
Q6 UYSEG