bio 4.1-4.3 study guide

Autotroph

A living thing that can make its own food using sunlight or chemicals; also called a producer.

Primary Producer

Organisms that produce energy-rich compounds used by other organisms; typically autotrophs like plants or algae.

Photosynthesis

Process by which autotrophs use sunlight, carbon dioxide, and water to produce food (glucose) and oxygen.

Chemosynthesis

Process by which some organisms use chemical energy (instead of sunlight) to make food.

Heterotroph

An organism that must consume other organisms for food; also called a consumer.

Consumer

Organisms that eat other organisms for energy; includes herbivores, carnivores, omnivores, and decomposers.

Detritus

Dead organic matter such as fallen leaves or dead animals, which provides food for decomposers.

Food Chain

A series of steps in which organisms transfer energy by eating and being eaten.

Phytoplankton

Microscopic plant-like organisms in aquatic ecosystems that carry out photosynthesis and form the base of many aquatic food chains.

Biosphere

The part of Earth where all life exists, including land, water, and the atmosphere.

Ecology

The scientific study of interactions among organisms and between organisms and their environment.

Species

A group of similar organisms that can breed and produce fertile offspring.

Population

A group of individuals of the same species that live in the same area at the same time.

Community

All the different populations that live together in a defined area.

Ecosystem

All the living (biotic) and nonliving (abiotic) components of an environment and how they interact.

Biotic Factor

A living part of the environment that affects other organisms (e.g., plants, animals, bacteria).

Abiotic Factor

A nonliving part of the environment that affects living organisms (e.g., temperature, water, sunlight).

Atmosphere

The layer of gases surrounding Earth that supports life and weather systems.

Hydrosphere

All the water on Earth, including oceans, lakes, rivers, groundwater, and ice.

Geosphere

The solid parts of the Earth, including rocks, soil, and the Earth's interior.