Multiple Choice Questions
Environmental Science: Biodiversity and Ecosystems
Topic: Biodiversity and Ecosystems
Grade: 11
Question 1:
Which of the following is an example of a keystone species?
A) African elephant
B) Blue whale
C) Honey bee
D) Kangaroo
Answer: C) Honey bee
Explanation: A keystone species is one that has a disproportionately large impact on its environment relative to its abundance. In the case of honey bees, they play a crucial role in pollinating plants, which is essential for the reproduction of many flowering plants. Without honey bees, the ecosystem would suffer a decline in plant diversity and productivity. This is a complex question as it requires understanding the concept of keystone species and their ecological importance.
Example 1 (Simple): If honey bees were to disappear, it would result in a decrease in the number of fruits and vegetables available for human consumption, affecting our food supply.
Example 2 (Complex): In the forests of North America, the keystone species is the gray wolf. The presence of wolves helps regulate the population of herbivores such as deer, preventing overgrazing and allowing vegetation to flourish.
Question 2:
Which of the following is an example of a primary consumer?
A) Hawk
B) Earthworm
C) Lion
D) Snake
Answer: B) Earthworm
Explanation: A primary consumer is an organism that feeds directly on producers (plants). Earthworms are detritivores, which means they consume decaying organic matter in the soil. This makes them an important part of the nutrient cycling process in ecosystems. This question tests the understanding of trophic levels and the role of primary consumers.
Example 1 (Simple): Rabbits are also examples of primary consumers as they eat grass and other plants.
Example 2 (Complex): In aquatic ecosystems, zooplankton such as Daphnia are primary consumers, feeding on algae and other microscopic organisms.
Question 3:
Which of the following is a characteristic of a stable ecosystem?
A) High biodiversity
B) Low species competition
C) Rapid nutrient cycling
D) Limited energy flow
Answer: A) High biodiversity
Explanation: High biodiversity is a characteristic of a stable ecosystem as it indicates a variety of species and genetic diversity. This diversity helps to maintain ecological balance and resilience in the face of disturbances. The more diverse an ecosystem is, the better it can withstand changes and recover from disturbances. This question assesses knowledge of ecosystem stability and the importance of biodiversity.
Example 1 (Simple): A forest with many different tree species is considered more stable than a monoculture plantation.
Example 2 (Complex): Coral reefs are highly biodiverse ecosystems, and their stability is crucial for the survival of numerous marine species. When coral reefs experience bleaching events due to environmental stressors, the loss of biodiversity can have cascading effects on the entire ecosystem.
Question 4:
Which of the following is an example of a natural disturbance in an ecosystem?
A) Logging activities
B) Oil spill
C) Volcanic eruption
D) Construction of a dam
Answer: C) Volcanic eruption
Explanation: A volcanic eruption is a natural disturbance that can have significant impacts on ecosystems. It can release ash, gases, and lava, altering the landscape and affecting the distribution of species. This question tests knowledge of natural disturbances and their effects on ecosystems.
Example 1 (Simple): A wildfire caused by lightning is another example of a natural disturbance.
Example 2 (Complex): The annual flooding of the Amazon River is a natural disturbance that replenishes nutrients in the surrounding floodplain and supports the unique biodiversity of the region.
Question 5:
Which of the following is an example of a pioneer species?
A) Oak tree
B) Moss
C) Blue jay
D) Squirrel
Answer: B) Moss
Explanation: Pioneer species are the first to colonize a barren or disturbed area. Mosses are often the first plants to establish themselves in such environments, as they can tolerate harsh conditions and help create suitable conditions for other plant species to grow. This question requires knowledge of succession and the role of pioneer species in ecosystem development.
Example 1 (Simple): Lichens are also pioneer species, often found growing on rocks or bare soil.
Example 2 (Complex): In the aftermath of a volcanic eruption, the first plants to colonize the barren landscape are usually small, fast-growing species like grasses and herbaceous plants.