Question 1: Define the term 'ecosystem' and explain why it is considered a dynamic system.

Answer: An ecosystem is a community of living organisms interacting with each other and their physical environment within a specific area. It is considered dynamic because it involves constant changes and interactions, such as energy flow, nutrient cycling, and population fluctuations.

Question 2: Describe the main differences between a tropical rainforest and a desert ecosystem in terms of climate, vegetation, and animal adaptation.

Answer: A tropical rainforest has a hot, humid climate with high rainfall, supporting dense, tall vegetation and a diverse range of animal species adapted to moist conditions. In contrast, a desert has low rainfall, high temperatures during the day, and sparse vegetation such as cacti, with animals adapted to conserve water and withstand extreme heat.

Question 3: Explain the role of producers, consumers, and decomposers within an ecosystem.

Answer: Producers, such as plants, create energy through photosynthesis and form the base of the food chain. Consumers, like herbivores and carnivores, feed on other organisms to obtain energy. Decomposers, such as fungi and bacteria, break down dead organic material, recycling nutrients back into the soil.

Question 4: Identify and describe one example of a biome and discuss how its climate influences its ecosystem.

Answer: A savannah is a biome characterized by grasslands with scattered trees, found in regions with a warm climate and seasonal rainfall. The climate influences the ecosystem by supporting grasses and drought-resistant trees, and it determines the types of animals that can survive there, such as elephants and lions.

Question 5: Discuss how human activities can impact ecosystems negatively. Provide two specific examples.

Answer: Human activities can harm ecosystems through deforestation, which destroys habitats and reduces biodiversity, and pollution, which contaminates water and soil, harming plants and animals. For example, logging in rainforests can lead to habitat loss, while oil spills in oceans can devastate marine life.

Question 6: Describe the process of succession in an ecosystem, using a simple example.

Answer: Succession is the natural process of change in the types of species in an ecosystem over time. For example, in primary succession, after a volcanic eruption, bare rock is gradually colonized by mosses and lichens, followed by grasses, shrubs, and eventually trees, leading to a mature forest.

Question 7: Sketch a simple diagram showing the flow of energy through a food chain in a grassland ecosystem. Include at least three different organisms and indicate the direction of energy flow.

Answer: A correct sketch would depict a sequence starting with a grass (producer), an herbivore such as a rabbit (primary consumer), and a carnivore such as a fox (secondary consumer). Arrows should point from the grass to the rabbit and from the rabbit to the fox, illustrating energy transfer.

Question 8: Explain why biodiversity is important for the stability of ecosystems.

Answer: Biodiversity is important because a variety of species ensures resilience against environmental changes, supports ecological functions like pollination and nutrient cycling, and provides resources such as food and medicine for humans.

Question 9: Identify two ways in which climate change can affect ecosystems globally.

Answer: Climate change can lead to rising temperatures, which may cause habitat loss and species extinction. It can also alter rainfall patterns, resulting in droughts or floods that disrupt existing ecosystems.

Question 10: Describe how a coral reef ecosystem is affected by changes in ocean temperature and acidity.

Answer: Increased ocean temperatures cause coral bleaching, where corals lose their symbiotic algae and may die. Higher acidity levels, due to increased carbon dioxide, weaken coral skeletons and hinder their growth, threatening the entire reef ecosystem.