Life Sciences - Term 3 - Week 1

An ecosystem is a community of living organisms interacting with their physical environment. It includes biotic factors, such as plants, animals, and microorganisms, and abiotic factors, such as water, soil, and climate. Ecosystems can vary in size and complexity, from a small pond to a vast forest. Each organism plays a specific role, contributing to the overall health and functionality of the ecosystem.

Biodiversity refers to the variety of life forms within a given ecosystem. It is crucial for ecosystem resilience, providing stability and the ability to recover from disturbances. High biodiversity ensures that ecosystems can withstand environmental changes and continue to provide essential services, such as clean air, water, and food. Loss of biodiversity can lead to ecosystem collapse and reduced quality of life for all organisms, including humans.

Consider a forest ecosystem. It consists of various trees, shrubs, animals, fungi, and microorganisms. Each species has a role, such as producers (plants), consumers (herbivores and carnivores), and decomposers (fungi and bacteria). If a key species, like a top predator, is removed, it can lead to overpopulation of herbivores, which may result in overgrazing and ultimately harm the plant life, demonstrating the interconnectedness of species within the ecosystem.

Students will work in groups to identify a local ecosystem, such as a park or a riverbank. They will list the biotic and abiotic components they observe, discuss the roles of different organisms, and consider how human activities, such as pollution or urban development, might affect this ecosystem. Each group will present their findings to the class, highlighting the importance of maintaining biodiversity.

Students will choose an endangered species and research its habitat, role in the ecosystem, and the factors contributing to its decline. They will prepare a report that includes information on conservation efforts and propose solutions to protect the species. This project will help students understand the direct impact of biodiversity loss and the importance of conservation.

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

Answer: To provide energy for consumers

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

• Increased ecosystem stability
• Greater resilience to environmental changes
• Higher risk of ecosystem collapse
• Improved air quality

Answer: Higher risk of ecosystem collapse

Reduced biodiversity weakens ecosystem resilience, making it more vulnerable to disturbances and collapse.

Answer: Biodiversity is the variety of different species of plants, animals, and microorganisms in a particular ecosystem.

Biodiversity encompasses the range of life forms and their interactions within an ecosystem.

• Plants
• Animals
• Soil
• Bacteria

Answer: Soil

Abiotic factors are non-living components of an ecosystem, such as soil, water, and climate.

Answer: Pollution and deforestation.

Both pollution and deforestation can lead to habitat loss and degradation, threatening various species.

• A species that is the most abundant in an ecosystem
• A species that has a disproportionately large impact on its environment
• A species that is at the top of the food chain
• A species that is endangered

Answer: A species that has a disproportionately large impact on its environment

Keystone species play a critical role in maintaining the structure of an ecosystem, and their removal can lead to significant changes.