Final answer:
An object is considered alive if it demonstrates key characteristics such as response to stimuli, growth and development, reproduction, homeostasis, complex chemistry, and a cellular structure.
Step-by-step explanation:
Characteristics of Living Things
To determine whether something is alive, scientists look for certain characteristics that all living things possess. An object must display several traits to be classified as living:
It responds to the environment, evidencing that it can detect and react to stimuli.
It grows and develops, showing changes in size, complexity, or both as it goes through life stages.
It has the ability to reproduce, meaning it can produce offspring to pass on its genetic material.
It maintains homeostasis, which is the regulation of its internal environment to maintain a stable, constant condition.
It exhibits complex chemistry, including metabolic processes.
It is made up of cells, the basic units of life.
In addition to these traits, living organisms exhibit other properties such as order, adaptation, energy processing, and evolution. To assess if something is living, all these characteristics must be considered together.
Investigating a Suspected Living Object
For instance, if one comes across an object resembling a dead twig, which could be a stick insect, observation and tests could reveal whether it's truly a living thing. One could check for movement, even subtle, watch for growth over time, or provide stimuli to see if there's a response. Moreover, examining for cell structures under a microscope could confirm if the subject has cellular composition.