Ecosystems and interdependence

In a nutshell

Organisms depend on other organisms for survival. Plants capture energy from the sun and use this to make their own food. Animals need energy so they eat plants that have this stored energy from the sun. Plants are dependent on insects as insects are necessary to pollinate crops so fruits can grow.

Ecosystems

Definition

An ecosystem is all the living things in one area and their environment.

Organisms in an ecosystem rely on one another to survive, this is known as interdependence.

Plants and energy

The Sun provides almost all the energy on Earth. Plants use this energy to make glucose in a process called photosynthesis. This glucose can then be used by the plants to build molecules that help them grow.

Example

Plants use food to build proteins that become part of their cells.

These molecules store the Sun's energy. This energy is then passed onto animals when they eat the plants. It then gets passed on again when animals are eaten by other animals.

Note: Animals do not carry out photosynthesis so they get their energy by eating plants and other animals.

Science; Interactions and interdependencies; KS3 Year 7; Ecosystems and interdependence — 1. Shows the direction of energy transfer.

Gas exchange

During respiration, plants and animals take in oxygen and give out carbon dioxide. During photosynthesis, plants give out oxygen and take in carbon dioxide. Without plants, there would not be enough oxygen for respiration and too much carbon dioxide in the air.

Plants depend on insects

Some plants depend on insects to reproduce. Crops such as corn are grown for food and these crops need insects to pollinate them. If these crops are not pollinated, they will not be able to make the fruit and seeds that we eat. This is why insects are needed to pollinate crops and provide us with food.