Biological Hierarchy & Characteristics of Life Vocabulary Flashcards

24 vocabulary flashcards covering the levels of biological hierarchy and the five key characteristics that define life.

Biological Hierarchy

A system for organizing living things from the smallest chemical units up to the entire biosphere.

Atoms & Molecules

The tiniest chemical building blocks that compose all matter, including living organisms.

Cells

The basic, smallest units of life; made of atoms and molecules and contain DNA.

Tissues

Groups of similar cells working together to perform a specific function.

Organs

Structures composed of different tissues that carry out specialized jobs.

Organ Systems

Groups of organs that cooperate to perform major bodily functions.

Organism

A complete individual living thing, such as an animal, plant, or microbe.

Population

All individuals of the same species living in a particular area.

Community

Different populations of organisms living and interacting in the same place.

Ecosystem

A community of organisms plus the non-living environment with which they interact.

Biome

A large geographic region characterized by a specific climate and dominant life forms (e.g., desert, forest).

Biosphere

All regions of Earth that support life; the sum of all biomes.

Cellular Composition

The requirement that all living things are made of one or more organized cells.

Reproduction

The biological process by which living organisms produce offspring and pass on DNA.

Response and Adaptation

The ability of organisms to react to stimuli and adjust over time to survive and maintain homeostasis.

Metabolism

All chemical processes that obtain and use energy to sustain life.

Evolution

Long-term genetic change in populations, often driven by mutations, leading to adaptation.

Homeostasis

The maintenance of stable internal conditions despite external environmental changes.

Autotroph

An organism that makes its own food, typically through photosynthesis.

Heterotroph

An organism that must consume other organisms to obtain energy.

Unicellular Organism

A living thing composed of a single cell (e.g., bacteria).

Multicellular Organism

A living thing composed of many specialized cells (e.g., humans, plants).

DNA

Deoxyribonucleic acid; the molecule that carries genetic instructions for life.

Mutation

A random change in DNA that can introduce genetic variation and drive evolution.