Something is considered alive if it exhibits several key characteristics shared by all living organisms. These include:
- Organization : Living things are made of cells, which are specialized parts performing specific functions
- Metabolism : They consume energy and use it for growth, repair, and other activities
- Homeostasis : The ability to maintain a stable internal environment despite external changes, such as regulating body temperature
- Growth and Development : Living things grow and undergo developmental changes over time
- Reproduction : They can produce offspring, passing on genetic information to the next generation
- Response to Stimuli : Living organisms respond to changes in their environment
- Evolution : Populations of living organisms can change over generations through evolution
These criteria help distinguish living things from nonliving things. However, there are exceptions and debates, such as whether viruses are alive since they reproduce only inside host cells and lack cellular structure
. In summary, life is characterized by a combination of cellular organization, energy use, homeostasis, growth, reproduction, response to environment, and evolutionary capability
