Rapid Revision For School Students

Join Us
Unit 1 - Energy Loss in Food Chains
A predator is usually found at the top of a pyramid of biomass.

Unit 1 - Energy Loss in Food Chains

This GCSE Biology quiz is all about food chains and the loss of both energy and biomass that occurs at each stage - from producers to primary and secondary consumers.

A food chain shows how the organisms in a particular habitat depend on each other as a source of food. At the start of any food chain is a producer which is normally a green plant. It is called a producer because it produces its own energy and food from raw materials it finds in its surroundings. Following on from the producer are the consumers, so called because they must eat something else. The first of these are called primary consumers and they are herbivores as all they eat are plants. Animals that feed on the primary consumers are called secondary consumers whilst tertiary consumers feed on the secondary consumers. Secondary consumers are carnivores or omnivores, as are the tertiary consumers. At the opposite end of a food chain to the producers is the top predator.

Food chains are usually short, rarely containing more than 3 or 4 consumers. This is because there is a loss of both energy and biomass in each stage of the chain. The entire amount of energy and biomass for a food chain is contained in the producers - call that 100%. When this is eaten by the consumers, all of it is passed on. The primary consumer uses some of this energy for respiration in its cells which enables it to stay alive, move etc. The rest becomes part of the biomass of the primary consumer and is passed along the food chain; so less than the original 100% is available to the secondary consumers. This happens at each stage of the food chain and nothing hunts the top predator because it would take more energy than would be gained from eating it.

We can see the loss of biomass and energy by observing the numbers and sizes of organisms in food chains. The biomass of living organisms at each successive stage in a food chain can be represented using pyramids of numbers and/or pyramids of biomass.

Which type of organism is usually found at the top of a pyramid of biomass?
Primary consumer
Predators are always found at the top of the energy pyramid and plants are always at the bottom
Which of the following statements about energy is true?
Energy is only ever created
Energy is only ever destroyed
Energy is only ever converted
Energy is only ever killed
This is the Conservation of Energy principle. All of the original energy of a food chain is still there but some of it has been spread out into the environment and is no longer available to the organisms of the food chain
The producer is usually what type of organism?
A fungus
An animal
A plant
A bacterium
Chlorophyll in plant cells uses the energy from sunlight to convert carbon dioxide and water into glucose. This process, photosynthesis, also releases oxygen into the atmosphere
Which process in green plants traps sunlight energy?
This is done by the chlorophyll
Which of the following statements about algae in a food chain is true?
Algae are always the primary consumer
Algae are always the secondary consumer
Algae are always the producer
Algae are always the predator
Algae are found almost everywhere on Earth and are the producer for many marine and freshwater food chains. It is said that 70% of the oxygen in the atmosphere is produced by algae
What happens to the biomass at each successive stage in a food chain?
It is increased
It remains the same
It is reduced
It is all lost
Not all of the biomass eaten as food remains in the consumer's body. Some is lost through excretion and respiration
Which of the following is not a way in which energy is lost from animals in a food chain?
Movement such as flying or running
Inedible parts of the prey
Urine and faeces
Photosynthesis occurs only in plants
Energy for all food chains comes from what source?
All energy for living things comes from the Sun. Plants trap this energy and use it to make food which provides energy for animals
Energy in which form is lost to the surroundings in a food chain?
Ultimately, all energy conversions result in heat
How is most energy in food chains lost?
Energy in food chains is mainly lost due to death and decay
Energy in food chains is mainly lost due to respiration and excretion
Energy in food chains is mainly lost due to reproduction and breathing
Energy in food chains is mainly lost due to reflection and transmission
The energy and biomass lost from a food chain by death and decay is recycled by the decomposers
You can find more about this topic by visiting BBC Bitesize - Using food and controlling growth

Author:  Donna Maria Davidson

© Copyright 2016-2023 - Education Quizzes
TJS - Web Design Lincolnshire

Valid HTML5

We use cookies to make your experience of our website better.

To comply with the new e-Privacy directive, we need to ask for your consent - I agree - No thanks - Find out more