Life Sciences - Term 3 - Week 7

An ecosystem is a community of living organisms interacting with their physical environment. It includes both biotic factors, such as plants and animals, and abiotic factors, like water, soil, and climate. Ecosystems can vary in size and complexity, from a small pond to a vast forest. Each ecosystem functions through a series of interactions among its components, which contribute to the overall health and sustainability of the environment.

Biodiversity refers to the variety of life in a particular habitat or ecosystem. It encompasses the diversity of species, genetic variation within those species, and the variety of ecosystems themselves. High biodiversity is crucial for ecosystem resilience, allowing ecosystems to withstand environmental changes and disturbances. It also provides resources for food, medicine, and ecosystem services such as pollination and nutrient cycling.

A food chain illustrates the linear feeding relationships between organisms, starting with producers like plants, followed by primary consumers (herbivores), secondary consumers (carnivores), and decomposers. For example, in a grassland ecosystem, grass (producer) is eaten by a rabbit (primary consumer), which is then eaten by a fox (secondary consumer). Food webs are more complex, showing how multiple food chains interconnect, highlighting the interdependence of species within an ecosystem.

In groups, students will select a local ecosystem (e.g., a park, river, or forest) and identify its components. They will categorize organisms as producers, consumers, or decomposers and discuss their roles. Each group will present their findings, explaining how these components interact and contribute to the ecosystem's health.

Students will choose a specific ecosystem and conduct research on its biodiversity. They will create a presentation that includes the types of species found, their roles in the ecosystem, and the current threats to biodiversity in that area. The project will emphasize the importance of conservation efforts and how individuals can contribute to protecting biodiversity.

• To decompose organic matter
• To provide energy for consumers
• To compete for resources
• To regulate population sizes

Answer: To provide energy for consumers

Producers, such as plants, convert sunlight into energy through photosynthesis, forming the base of the food chain.

• Grass
• Rabbit
• Fungi
• Eagle

Answer: Fungi

Decomposers like fungi break down dead organic matter, recycling nutrients back into the ecosystem.

Answer: Biodiversity is the variety of life in a particular habitat or ecosystem, including the diversity of species, genetic variation, and ecosystem variety.

Biodiversity is essential for ecosystem resilience and provides numerous benefits to humans and the environment.

• A linear sequence of energy transfer
• A complex network of feeding relationships
• A diagram showing only producers
• A list of all organisms in an ecosystem

Answer: A complex network of feeding relationships

A food web illustrates how various food chains are interconnected, showing the complexity of interactions in an ecosystem.

Answer: Biodiversity contributes to ecosystem stability by allowing ecosystems to adapt to changes and recover from disturbances.

Higher biodiversity means a greater variety of species that can fulfill different roles, enhancing resilience against environmental changes.

• Habitat destruction
• Conservation efforts
• Sustainable practices
• Pollination

Answer: Habitat destruction

Habitat destruction, often due to human activities, is a major threat to biodiversity, leading to species extinction.