From the beginning of Biology, scientists have wrestled with the idea “What makes something alive?”
There’s still a little disagreement on how these characteristics are listed, but generally, living things…
- are composed of cells.
- Cells are the basic building block of all living things. Whether plant, animal, fungus, or bacterium, all living things have some type of cellular structure. Many organisms contain multiple cells that work together.
- show internal organization.
- The parts and structures of a living thing aren’t just randomly thrown together. They are organized and often layered into tissues and body systems.
- use energy.
- Plants and other producers use energy from the sun while animals and other heterotrophs have to eat to gain energy, but all organisms require energy to accomplish the functions they need to survive.
- respond to the environment.
- When you hear a noise, you turn towards it. Likewise, all living things respond to stimuli or changes in the world around them.
- grow.
- Some adult organisms look very similar to their newborn bodies. Others, like insects and frogs, go through elaborate stages of metamorphosis to form their adult bodies.
- reproduce.
- The ability to pass traits to offspring is essential for a group of organisms to continue to survive.
- adapt to their environment.
- Groups of organisms are able to adapt and change based on changes in their environment. If these changes are passed down to offspring, the group of organisms may evolve over time.
