4.1 Species, Communities, Ecosystems & Energy Flow

This is a simple food web found in an ocean ecosystem.

Identify an example of an organism from the food web which obtains food using the method of nutrition named in the table.

Identify an organism (or a group of organisms), not shown in the ocean food web, which feeds on all trophic levels of the food chain.

Each of the three sentences about ecosystems contains one error.

• In a functioning ecosystem, organisms are constantly recycled.
• Detritivores obtain inorganic nutrients from the abiotic environment and convert them to organic molecules during photosynthesis.
• Decomposition is fundamental in ensuring that ecosystems remain unsustainable over long periods of time.

Place a (✓) or (X) in the correct columns for each of the factors listed in the table below:

Abiotic factors can be controlled in order to study the response of a naturally occurring ecosystem using the set up below.

What is the name given to the set up shown in the image which allows the study of ecosystems?

[1 mark]

• A transparent container
• A lid to seal the container
• Minimal primary consumers and no secondary consumers

[3 marks]

A mesocosm was set up to study the effect of increasing global temperatures on the biomass of aquatic autotrophs and heterotrophs.

The graph shows the data collected.

When a consumer eats another organism, it converts chemical energy into other forms of energy, such as heat energy. This is represented in the energy transfer diagram below.

A blackbird ate snails containing 1150 kJ of energy. Only 10% of this energy was transferred to the blackbird.

The diagram shows the movement of energy through a food web.

One mark is available for clarity of communication throughout this question.