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

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.

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

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

Estimating population size and distribution using transects: practical

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

Physical activity and equipment requiring safe use

A straight line between two points that is used to take measurements and observations is called a {{}}.

How many insects are found on the species being sampled.

Which of the following are abiotic factors that could be measured in a meadow while sampling an organism?

The number of a species that is found within a habitat.

The range of different species found within a habitat.

The geographical area in which a species can be found.

when you randomly put a quadrat on the ground when sampling.

when you throw a quadrat to randomly sample an area with a quadrat.

when you place a quadrat at regular intervals along a transect to sample. 

when you randomly place a quadrat along a transect.

There will be no plants in the shade under the tree.

What might happen to the abundance of plant species along a transect as you leave the shade of a tall Oak tree?

To work out if a species is becoming extinct.

To look at changes in the food chain diagram.

To look at changes in the abundance of a species.

To measure the mean number of species in an area.

Why might scientists want to place quadrats along a transect to observe and measure a species?

Which of the following organisms might you sample using a quadrat?

How many red flowers are there in the quadrat?

Pick the area that looks the best and place the quadrat.

Using a random number generator to get coordinates to place the quadrat.

Throw the quadrat and sample where it lands.

Look for where there are less plants so it is easier to sample.

How might you select random areas to sample using a quadrat?

So that the sample is reliable - it represents the whole area.

When sampling an area using a quadrat, why do you need to make sure that you take as many samples as possible?

A pupil records the number of chickweed plants in 5 quadrats. She records the following observations: 4, 7, 9, 5 and 10 plants. What is the mean number of chickweed plants in each quadrat?

Black medick plants were sampled using a quadrat (1 m²). After 10 samples, 80 black medick plants were counted. The field is 400 m². What is the estimated population of the plant?

Content guidance

Risk assessment required - equipment

Adult supervision required

This lesson will be removed by end of Summer Term 2025.

Estimating population size and distribution using transects: practical

Lesson outcome

Content guidance

This lesson will be removed by end of Summer Term 2025.