Practise IB Biology HL D4.2 with ecosystem data questions on stability, succession, biomagnification, pollution, keystone species and sustainable resource use.
Outline the features of ecosystems that make them sustainable.
An investigation into food web interactions was conducted in mesocosms in the Mediterranean Sea, off the coast of France. The effects of the addition of soil and fish on bacterial populations were tested.
Suggest advantages of undertaking this experiment in the sea rather than in the laboratory.
The gut of a healthy human contains more than 1000 species of bacteria. Some of these species are shown in the cladogram.
Scientists have found that B. fragilis and B. stercosis are keystone species in the human gut ecosystem.
Define keystone species.
Over time, the populations of different species of bacteria in the human gut can produce a stable climax community.
Suggest how some antibiotics, prescribed for bacterial infections, can disrupt the climax community in the gut.