bio eco 1 and 2 combined

Ecosystem

All living and non-living things interacting in an area.

Abiotic factors

Non-living components of an ecosystem, like sunlight, rain, temperature, and pH.

Biotic factors

Living components of an ecosystem, such as producers, consumers, and decomposers.

Biotope

A defined area with specific abiotic and biotic factors.

Habitat

A specific part of a biotope where an organism lives and reproduces.

Niche

The role and way of life of an organism, including how it interacts with others.

Population

All individuals of the same species in a particular area.

Community

Different populations living together in the same area.

Symbiosis

A close relationship between species, including mutualism, parasitism, and commensalism.

Predation

When one organism kills and eats another.

Carrying capacity

The largest population size an environment can support.

Producers (autotrophs)

Organisms that make their own food, like plants and some bacteria. Photoautotrophs use sunlight for energy. Chemoautotrophs use chemical reactions for energy.

Consumers (heterotrophs)

organisms that get food from other organisms because they cannot make their own food. They include herbivores (eat plants), carnivores (eat animals), omnivores (eat both plants and animals), and detritivores (consume dead organic matter).

Decomposers (saprotrophs)

Organisms that break down dead plants and animals, recycle nutrients back into the soil or water, and make them available for producers. Examples include fungi, bacteria, and some types of worms.

Cellular respiration

The process of breaking down glucose with oxygen to make ATP (usable energy), releasing carbon dioxide and water; occurs in mitochondria of plants and animals with enzyme help.

Photosynthesis

Process where plants, algae, and some bacteria use sunlight, carbon dioxide, and water to make glucose and oxygen (6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂).

Food chain

A simple path of energy flow showing who eats whom in an ecosystem; always starts with a producer and ends with a top consumer.

Top consumer

The highest predator in a food chain with no natural enemies (e.g., hawk, shark, wolf).

Food web

Many connected food chains that show the full feeding network of an ecosystem; consumers can occupy more than one trophic level.

Role of producers

Capture light energy and make chemical energy (glucose) that supports all other organisms.

Autotrophs vs heterotrophs

Autotrophs make their own food from inorganic sources (photoautotrophs use sunlight, chemoautotrophs use chemicals). Heterotrophs must eat other organisms for energy.

Primary vs secondary consumer

Primary consumers eat producers (herbivores). Secondary consumers eat primary consumers (carnivores or omnivores).

Trophic level

A feeding step in a food chain or web, such as producer, primary consumer, secondary consumer, or top consumer.

Typical top consumers

Large predators like hawks, wolves, or sharks.

Energy transfer

Only about 10% of energy moves from one trophic level to the next; the rest is lost.

Energy loss forms

Heat from metabolism and movement, excretion, faeces, and unconsumed material.

Why food chains are short

Less energy is available at higher levels, so only a few trophic levels can be supported.

Energy flow vs nutrient cycling

Energy enters as sunlight and leaves as heat (one-way). Nutrients are recycled by decomposers and reused by producers.

Ecological pyramids

Three ways to show energy and matter: pyramid of numbers, pyramid of biomass, and pyramid of energy.