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

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

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

What is the name of the flammable gas found in biogas?

What is an organism that feeds on waste or dead organic matter called?

They provide animals with the nitrogen they need to be healthy.

They provide plants with the nitrogen that they need to make proteins.

Nitrates are released into the soil by decomposers when they breakdown waste and dead organisms. Why is it important that the nitrates are released into the soil?

Biogas is made during the decomposition of manure or crops (e.g. maize) in anaerobic conditions. What does the term anaerobic refer to?

A natural fertiliser made from plant materials.

A natural fertiliser made from animal waste.

An organism that feeds on the remains of other living organisms.

Match the words with the correct description.

What is the name of the process where living organisms return carbon in their bodies back into the atmosphere?

All the organisms of the same or closely-related species in an area.

The interactions between populations in a habitat.

temperature, humidity, competition for food

altitude, rock type, dissolved oxygen concentration in water

disease, competition for a mate, competition for shelter

Which of the following are examples of only abiotic factors?

Which of these is a behavioural adaptation seen in some animals?

Humans depending upon other organisms for food.

When no organisms in a food web depend upon each other.

When all organisms in a food web depend upon each other.

The process of breaking down material to release nutrients back into the soil.

The process by which microorganisms release carbon dioxide.

The speed at which dead matter is broken down.

The introduction of a new predator to a habitat.

A new disease impacting a population of organisms.

The availability of mineral ions in the soil.

Which of the following is not an example of a biotic factor?

This lesson will soon be taken down.

The role of microorganisms in decomposition

Lesson outcome