Living Things in Ecosystems

Description:

• This chapter helps students understand the concept of ecosystems and how all living and non-living things are interconnected. An ecosystem is a natural system where living organisms (plants, animals, microorganisms) interact with their physical environment (air, water, soil, sunlight).

Components of an Ecosystem:

• Biotic (Living):
• Producers (Autotrophs): Plants, algae—make their own food through photosynthesis.
• Consumers (Heterotrophs): Animals that depend on others for food:
• Herbivores (plant eaters), Carnivores (meat eaters), Omnivores (both), Parasites (depend on host).
• Decomposers: Fungi and bacteria that recycle nutrients from dead matter.
• Abiotic (Non-living): Soil, air, water, temperature, sunlight, minerals.

Types of Ecosystems:

• Natural ecosystems: Forests, deserts, grasslands, ponds, rivers, oceans.
• Artificial ecosystems: Man-made, such as crop fields, gardens, aquariums.

Food Chains and Food Webs:

• Food chain: A direct sequence of who eats whom (e.g., grass → deer → tiger).
• Food web: A network of interconnected food chains, making ecosystems more stable.

Energy Flow in Ecosystems:

• Sunlight is the primary energy source.
• Only 10% of energy is passed from one level to the next (10% Law), limiting food chain length.

Ecological Balance and Human Impact:

• Each organism plays a role; imbalance occurs if species are removed. o Human actions like deforestation, overhunting, pollution, and habitat destruction disturb ecosystems.
• Conservation is essential to preserve biodiversity and maintain ecological balance.

• In short, ecosystems show that all living things depend on each other and their environment. Protecting ecosystems means protecting life itself.