DP Environmental Systems and Societies Questionbank

With reference to Figure 9(a), explain why the realized niche of the mottled sculpin has changed in recent years.

Suggest why the St Lawrence River beluga whale population has not recovered despite being given protected status in 1983.

Calculate the percent decrease in beluga whale numbers from 1920 to 1940.

Using Figure 7, state the St Lawrence beluga whale population in 1920 and 1940.

1920:

1940:

Distinguish between negative and positive feedback using examples from environmental systems.

Identify two possible effects of removing trout on this ecosystem.

Using Figure 1 below, calculate the annual rate of population increase for elephants in Zimbabwe from 1985 to 2005.

Figure 1   Elephant Population: Kenya compared to Zimbabwe, 1973 – 2011

Explain how predation may lead to long-term population decrease or extinction of the prey species.

Explain how predation may lead to stability in a population of the prey species.

Outline the similarities and differences between predation and competition.

Evaluate the possible use of grass carp in controlling the growth of water hyacinth in Inle Lake.

Distinguish between a mutualistic relationship and a parasitic relationship.

Identify one abiotic factor which may affect the population of insects in a forest.

Identify two possible reasons why species B and C were not present in the litter layer when it was resampled six months later.

Oystercatchers and avocets both feed on small animals in the mud of the wetlands. State the most likely relationship between these two species.

Outline the role of limiting factors in S and J population curves.

Define the term species.

Justify whether or not Mesquite should be cleared from the Swakop River Valley.

With reference to the data in Figure 4(b), suggest two conclusions which can be drawn from the camera trap data.

Explain how both positive and negative feedback mechanisms may play a role in producing a typical S population growth curve for a species.

Identify four impacts on an ecosystem that may result from the introduction of an invasive species of herbivore.

With reference to Figure 4(d), suggest the impact on the marine food web if tuna numbers were to decline.

With reference to Figure 10(b), explain the threats to the future existence of a small and sustainable population of wolves as a result of their protection in limited area.

With reference to Figures 9(a) and 9(b), describe one abiotic change and one biotic change in a beaver meadow community undergoing succession.

Identify three reasons why carrying capacity can be difficult to estimate.

Define the term carrying capacity.

Distinguish between the terms niche and habitat with reference to a named species.

Outline how this relationship may be of benefit to the populations of both species.