MCQ-6: Organisms and their Environment

The diagram shows part of the nitrogen cycle.

What could be responsible for process X?

Nitrogen in the air cannot be used by plants until it is in the form of nitrates.
Which two processes convert nitrogen from the air into nitrates?

What is shown by the widest block in a pyramid of numbers for a grassland ecosystem?

What is defined as ‘all of the populations of different species in an ecosystem’?

Which pyramid of numbers has more herbivores than producers?

The biomass at each trophic level in an ecosystem is measured. The results are shown in the table.
Which trophic level contains herbivores?

The diagram shows a food web.

What do the arrows represent?

The diagram shows part of the nitrogen cycle.

Which row correctly identifies the bacteria involved in processes W, X, Y and Z?

The graph shows a bacteria population curve.
In which phase on the graph is the number of bacteria dying equal to the number dividing?

The diagram shows a food web.

Which row shows a food chain in this food web?

The diagram shows part of the nitrogen cycle.
Which change is caused by the action of denitrifying bacteria?

The diagram shows a food web in the ocean.

Which two animals are secondary and tertiary consumers?

A student was given data on the change in the number of insects in a population over a period of twelve weeks. The student was asked to name and label each phase.

What is the correct label for phase three?

Which row describes the energy flow into and through a food chain that starts with a plant?

The diagram shows part of the nitrogen cycle.

What is one of the mineral ions?

What is a trophic level?

The diagram shows part of the nitrogen cycle.
At which stage is denitrification occurring?

What could be responsible for the conversion of nitrogen in the atmosphere to nitrates in the soil?

Which statement describes the effect of a disease which kills members of a population?

The diagram shows a pyramid of numbers in a food chain.

What type of organism is the tree shrew?