ecology

🌍 Ecology Unit Test – Study Notes

🌎 Earth’s Spheres

Lithosphere: Solid land (rocks, soil, mountains)

Hydrosphere: All water (oceans, rivers, groundwater, ice)

Atmosphere: Layer of gases surrounding Earth

Biosphere: All living organisms on Earth

🌱 Ecosystem

A system made of living (biotic) and nonliving (abiotic) parts interacting

Biotic Factors

Living things (plants, animals, bacteria, fungi)

Abiotic Factors

Nonliving factors (sunlight, water, temperature, soil, air)

👥 Levels of Organization

Population: Same species living in one area

Community: All populations living in an area

Ecosystem: Community + abiotic factors

☀️ Energy Flow from the Sun

Sun → plants → animals

Light energy is transformed into chemical energy by plants and transferred through food chains

🌿 Photosynthesis

What it is: Process plants use to make food using sunlight

Who uses it: Plants, algae, some bacteria

Word equation:

Carbon dioxide + Water + Light → Glucose + Oxygen

🔥 Cellular Respiration

What it is: Process that releases energy from food

Who uses it: All living organisms (plants & animals)

Word equation:

Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP)

🔄 Relationship Between Photosynthesis & Respiration

Products of one are reactants of the other

They form a cycle of energy and matter

🎯 Ecological Niche

The role of an organism in its environment

(what it eats, where it lives, how it survives)

🦌 Consumers

Herbivore: Eats plants

Carnivore: Eats animals

Omnivore: Eats plants and animals

Scavenger: Eats dead organisms

🍽️ Food Chain

A linear path of energy flow (producer → consumers)

🕸️ Food Web

Multiple food chains interconnected

🪜 Trophic Levels

Feeding positions in a food chain

Producer → primary → secondary → tertiary consumers

🔺 Ecological Pyramids

Pyramid of Numbers: Number of organisms

Pyramid of Biomass: Total mass of organisms

Pyramid of Energy: Energy available at each level

⚡ Trophic Efficiency