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

Biology

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 carbon cycle

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

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.

A population is a group of organisms of the same species living in the same place.

Sampling is a method of surveying plants and/or animals to provide information about the populations of organisms.

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

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

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.

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

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).

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

Decay is the breakdown (or rotting) of organic 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).

A protein which acts as a biological catalyst. This speeds up a reaction without being used up.

The rate is how quickly something takes place. The rate of a reaction is a measure of how much change occurs per unit of time.

The part of an enzyme where the substrate binds.

A measure of how acidic or alkaline a solution is.

The point at which a reaction is complete, often indicated by a change in colour of an indicator.

A precise, measurable and testable statement based on observations about how something works.

A permanent change in the shape of an enzyme which stops it from working.

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.

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

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