The atmosphere is a layer of gases that surround a planet. It may contain small amounts of solid and liquid particles.

In a combustion reaction, fuel is burned and reacts with oxygen to provide energy. Carbon dioxide is released in combustion reactions.

Cellular respiration is a chemical process in cells, which uses glucose as a fuel to provide energy for life processes.

Producers make their own food using a series of chemical reactions called photosynthesis. The reaction includes taking in carbon dioxide from the atmosphere.

Material cycles: the carbon cycle

Biology

Components of an ecosystem

Measuring the size and distribution of populations of organisms

Estimating population size using quadrats: practical

Estimating population size and distribution using transects: practical

Competition and adaptations in ecosystems

The role of microorganisms in decomposition

Factors affecting the rate of decomposition

The effect of temperature on the rate of decomposition by an enzyme: practical

The effect of temperature on the rate of decomposition by an enzyme: data analysis and evaluation

Material cycles: the water cycle

Pupils will learn about biomass transfer including calculating the efficiency of transfers between trophic levels. They will learn about human impacts on the environment, food security and biotechnology to help maintain biodiversity and achieve food security.

Pupils learned about interdependence within ecosystems and how plants and animals are adapted to their environment. Pupils undertook ecological sampling to estimate population sizes and looked at the impact of humans on biodiversity.

This unit explores ecosystem organisation, biotic and abiotic factors, material cycling, and the role of decomposers. It covers methods for identifying species and measuring their distribution. Emphasis is on selecting appropriate techniques, accurate measurements, sampling, and fieldwork practices.

Living organisms and their environments

What is the layer of gas called that surrounds the planet Earth?

Carbon dioxide is made up of two elements, carbon and oxygen. How many carbon atoms and oxygen atoms are in one molecule of carbon dioxide?

What percentage of the air we breathe is carbon dioxide?

It is adding more carbon dioxide to the atmosphere.

It is removing carbon dioxide from the atmosphere.

What is happening as a result of human activities such as deforestation and burning of fossil fuels?

Organisms that break down dead organisms and organic material are called ...

The image shows a part of the carbon cycle. Put the following words in the correct order from a to d.

For some organisms, animal waste and dead organisms are a useful source of ...

Organisms that break down dead organisms and waste materials are called ...

The apple tree in the image is an example of what type of organism?

What are the abiotic factors that can be seen in the image?

Snakes and succulents are two biotic factors in a desert ecosystem. Which two abiotic factors do they rely upon?

Low light intensity affects the growth of forest pine trees.

Moth caterpillars eat the leaves of apple trees.

Water temperature affects its oxygen level.

Eels survive by attaching themselves to trout.

Which of the following shows an **abiotic** factor interacting with a **biotic** factor in the environment?

Starter Quiz

For some organisms, animal waste and dead organisms are a useful source of ...