An ecosystem is made up of all the living organisms in a place, interacting with each other and their non-living surroundings.

A group of organisms of the same type in the same place is called a population.

A community is made up of all the organisms that live in the same place.

Biotic factors are the living components of an ecosystem.

Abiotic factors are the non-living components of an ecosystem.

Components of an ecosystem

Combined science

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.

Living organisms and their environments

A classification key is a series of questions about the features of organisms that help us to classify them correctly.

Estimate means to give an approximate value, for example, you can estimate the population of fish in a lake by sampling.

Sampling is a survey of plants and/or animals which provides information about the populations of organisms.

Measuring the size and distribution of populations of organisms

A group of organisms of the same type, in the same place, is called a population.

A quadrat is a square frame which is used to sample populations of plants or slow-moving animals.

Abundance is the number of organisms of a species found within a habitat.

Estimating population size using quadrats: practical

A transect is a straight line across a habitat that is used to make measurements and observations.

The distribution of a species is the geographical area in which a species can be found.

Estimating population size and distribution using transects: practical

Competition is when organisms in a community or population are seeking the same limited resource (e.g. food, mates).

An adaptation is a feature that organisms have to help them live in a particular place.

Physiological adaptations are body processes that help an organism to survive and reproduce.

A microorganism is an organism that can only be seen using a microscope.

Extremophiles are organisms that are able to successfully survive and reproduce in extreme environments (e.g. very hot/very cold).

Competition and adaptations in ecosystems

A decomposer is an organism that feeds on the remains of other living organisms (organic matter).

Decay is the breakdown (or rotting) of organism matter by bacteria, fungi, or other organisms.

Detritus is the remains of living organisms.

An enzyme is a protein that acts as a biological catalyst (a substance that speeds up a reaction).

The role of microorganisms in decomposition

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

Evaporation is the process of changing a substance from a liquid to a gas.

Condensation is the change of state from a gas to a liquid.

Transpiration is the loss of water vapour through the leaves of plants (through stomata).

Precipitation is water that falls from clouds in the form of rain, sleet, snow or hail.

Living organisms and their environments

Choose a lesson (8)

These lessons will be removed by end of Summer Term 2025.