Life Sciences - Term 4 - Week 9

An ecosystem is a community of living organisms interacting with their physical environment. It includes biotic factors such as plants, animals, and microorganisms, as well as abiotic factors like water, soil, and climate. Ecosystems can vary in size and complexity, from a small pond to a vast forest. The interactions among these components create a dynamic system where energy flows and nutrients cycle.

Biodiversity refers to the variety of life forms within a given ecosystem, biome, or on the entire planet. It encompasses the diversity of species, genetic variations, and the variety of ecosystems. High biodiversity contributes to ecosystem resilience, allowing it to withstand environmental changes and disturbances. It also provides essential services such as pollination, nutrient cycling, and climate regulation.

Consider a forest ecosystem. Trees provide shelter and food for various animals, while animals contribute to seed dispersal and pollination. Decomposers like fungi and bacteria break down dead organic matter, returning nutrients to the soil, which supports plant growth. This example illustrates the interconnectedness of species and their roles in maintaining ecosystem health.

In pairs, students will select a local ecosystem (e.g., a park, river, or garden) and identify its biotic and abiotic components. They will create a chart listing these components and describe their interactions. After 15 minutes, each pair will present their findings to the class, highlighting the importance of each component in maintaining the ecosystem's balance.

Students will choose an endangered species and research its role within its ecosystem. They will write a report that includes the species' habitat, its interactions with other organisms, and the impact of its decline on biodiversity. Reports should be at least 500 words and include references to at least three sources. Students will present their findings in the next class.

• Only plants
• Only animals
• Biotic and abiotic factors
• Only microorganisms

Answer: Biotic and abiotic factors

An ecosystem is made up of both living (biotic) and non-living (abiotic) components that interact with each other.

• The number of species in a specific area
• The variety of life forms in a given ecosystem
• The total biomass of an ecosystem
• The number of ecosystems on Earth

Answer: The variety of life forms in a given ecosystem

Biodiversity encompasses the variety of species, genetic diversity, and ecosystem diversity.

Answer: Biodiversity is crucial for ecosystem resilience, providing stability and the ability to recover from disturbances. It also supports ecosystem services like pollination and nutrient cycling.

High biodiversity allows ecosystems to function effectively and adapt to changes, ensuring survival and sustainability.

• Soil composition
• Temperature
• Plants
• Water availability

Answer: Plants

Biotic factors are living components of an ecosystem, while abiotic factors are non-living elements.

• They produce energy through photosynthesis.
• They consume primary producers.
• They break down dead organic matter.
• They compete with herbivores.

Answer: They break down dead organic matter.

Decomposers recycle nutrients back into the ecosystem by breaking down dead organisms.

Answer: The loss of a keystone species can lead to a collapse of the ecosystem, as it may disrupt food webs and lead to overpopulation or extinction of other species.