Humans and their effects on the environment Quiz

1. Which of the following best defines biodiversity?

• A. The variety of living organisms in an area
• B. The total number of individual organisms in an ecosystem
• C. The number of different species of plants only
• D. The genetic variation within a single species

2. Why is biodiversity important for ecosystem stability?

• A. It increases the amount of sunlight available to plants
• B. It allows ecosystems to better resist damage and recover from disturbances
• C. It reduces the need for water in the ecosystem
• D. It eliminates the need for decomposers

3. A farmer clears a large area of tropical rainforest to create cattle pasture. Which cause of biodiversity reduction does this primarily represent?

• A. Pollution
• B. Climate change
• C. Habitat destruction
• D. Invasive species

4. A nature reserve uses both seed banks and captive breeding programmes to protect endangered species. Evaluate which method is more effective for long-term conservation.

• A. Seed banks are always more effective because they preserve genetic material indefinitely
• B. Captive breeding is always more effective because it produces living organisms immediately
• C. Seed banks are more cost-effective for plant species, whilst captive breeding is necessary for animals; both are valuable as complementary methods
• D. Neither method is effective without international agreements to protect habitats

5. A student uses indicator species to assess water pollution in a river. They find very few mayfly nymphs but many rat-tailed maggots. What does this suggest about the water quality?

• A. The water quality is excellent with high dissolved oxygen levels
• B. The water is polluted with low dissolved oxygen levels, as rat-tailed maggots are indicators of poor conditions
• C. The water contains excessive nitrates causing eutrophication
• D. The water has been contaminated with invasive species