Populations in Ecosystems - exam practice

Two species of animal are found in the same area of forest and grassland. In the spring and summer they eat the same plant food. However, in the autumn and winter one eats nuts in the forest and the other eats roots on the grassland.

Both species are preyed upon by the same predator. Numbers of root-eating animals are reduced most by this, but they recover faster as they reproduce faster.

What can be concluded about these two species of animals?

1 - they are part of the same community

2 - they are at different trophic levels

3 - they occupy different habitats

4 - they have different niches

Which group could be a population?

What is the ecological definition of the term community?

Termites are insects that build large nests that contain millions of termites of the same species.

These nests are common in tropical savanna, which typically consists of grasses with widely spaced trees. Here, the termites feed on wood and other dead plant material.

Which statement is correct?

A tree carries out photosynthesis and provides organic compounds for other organisms in a forest.

It takes carbon dioxide from the atmosphere and returns oxygen to the atmosphere. It takes water from the soil into its roots and its leaves lose water to the atmosphere. Many other organisms live in the tree.

Which term describes the tree?

Deep sea vents on the ocean floor are surrounded by unusual organisms such as chemosynthetic bacteria and eyeless shrimp.

Which statement(s) about these ecosystems is/are true?

1 - the temperature of the vents influences the organisms that live there

2 - a predatory octopus would affect the balance of these organisms

3 - the number of eyeless shrimp found at each vent is constant

The first stage of primary succession is the pioneer community.

Which of the following statements about a pioneer community are correct?

1 - species produce large numbers of wind-carried seeds or spores

2 - biomass is low

3 - many species are lichens and mosses

Which of the following statements about ecosystems is not true?

A teacher wrote:

“A garden pond is a dynamic environment that is home to a variety of organisms. The temperature of the pond varies depending on the weather and the time of year, and this affects the populations of the species that live there.”

Which term applies to the teacher’s description of the garden pond?

Barnacles are small animals that live on rocky shores. Adult barnacles are fixed to rocks and do not move about. They catch passing food in the water with modified limbs called cirri when the tide comes in.

Chthalamus stellatus is a species of barnacle found around UK shores.

Two students wished to estimate the population size of C. stellatus on a rocky shore near their school.

What could the students use for estimating the C. stellatus population?

1 - an abundance scale, such as ACFOR

2 - quadrat sampling

3 - mark-release-recapture

Ash trees are common throughout the UK. They often grow in dense woodland.

What is an abiotic factor that is likely to affect the growth of young ash trees?