Question 1: Describe the main features of a tropical rainforest ecosystem, including the climate, flora, and fauna.

Answer: A tropical rainforest ecosystem features a hot and humid climate with high rainfall throughout the year. The vegetation is dense with tall trees forming a canopy, supporting a diverse range of plant species. The fauna includes numerous insects, birds, mammals, and reptiles adapted to the dense environment.

Question 2: Explain how climate influences the distribution of savannah and desert ecosystems in Africa.

Answer: Climate influences these ecosystems primarily through variations in rainfall and temperature. Savannas receive seasonal rainfall allowing grasses and scattered trees to grow, supporting herbivores and predators. Deserts have very low, unreliable rainfall and high temperatures, leading to sparse vegetation and specialized animals adapted to dry conditions.

Question 3: Compare the soil types typically found in a temperate deciduous forest and a tundra ecosystem.

Answer: Temperate deciduous forests usually have rich, fertile soils with high organic content due to leaf litter decomposition. Tundra soils are often frozen or very poor in nutrients, with a permafrost layer that limits drainage and plant growth.

Question 4: Explain the process of ecological succession in a pond ecosystem following a period of drying out.

Answer: After a pond dries out, pioneer species like algae and aquatic plants colonize the area. Over time, sedimentation and plant growth lead to the formation of marshland. As conditions stabilize, shrubs and trees may begin to grow, eventually leading to a terrestrial ecosystem if succession continues.

Question 5: Draw a simple diagram of a food chain in a grassland ecosystem, including at least four levels.

Answer: A correct sketch would show: (1) grass as the producer, (2) a herbivore such as a rabbit or insect as the primary consumer, (3) a small carnivore like a fox or bird as the secondary consumer, and (4) a top predator such as a hawk or larger carnivore. Arrows indicate energy flow from producers to consumers.

Question 6: Identify and explain two adaptations that animals in a desert ecosystem might have to survive extreme heat and scarce water.

Answer: Animals may have adaptations such as nocturnal behavior to avoid daytime heat, and physical features like long ears or specialized kidneys to conserve water.

Question 7: Describe the role of keystone species in maintaining the balance of a coral reef ecosystem.

Answer: Keystone species, such as certain sea stars or herbivorous fish, help control the population of other species, preventing overgrazing and maintaining biodiversity. Their presence ensures the stability and health of the entire coral reef.

Question 8: Explain how human activities, such as deforestation or pollution, can disrupt ecosystems. Provide specific examples.

Answer: Human activities like deforestation remove critical habitats, leading to loss of biodiversity and disrupted food webs. Pollution, such as chemical runoff into rivers, can harm aquatic life, cause algal blooms, and degrade water quality, affecting the entire ecosystem.

Question 9: Sketch a diagram showing the different layers of a forest ecosystem and label the main components of each layer.

Answer: A correct sketch would include the emergent layer, canopy, understory, and forest floor. Labels should identify features such as tall trees in the emergent and canopy layers, shrubs and smaller plants in the understory, and decomposing matter on the forest floor.

Question 10: Discuss the impact of climate change on polar ecosystems, focusing on ice melting and species adaptation.

Answer: Climate change causes polar ice to melt, reducing habitat for species like polar bears and seals. This affects their ability to find food and reproduce. Some species may adapt by migrating or changing their behaviors, but rapid environmental changes threaten their survival.