What Are Some Non-Living Objects That Each Display a Different Characteristic of Living Things?

Structure

• The structure of a living thing must have complexity and organization. The basic building block of all plants and animals is the cell, and cells form tissues that in turn make up the overall organism. Minerals are not alive, but the complex lattice structure of their crystals is similar to that of a cell.

Energy Consumption

• Plants and animals obtain and use energy to survive. Their metabolic processes allow them to transfer chemicals from their environment and process them to acquire energy. Plants do this by photosynthesis, while animals eat and digest food for their energy. In a similar way, an automobile releases energy from gasoline to run its engine and accessories.

Motion

• Living things, even plants that are firmly rooted in the ground, actively move at some time. All kinds of familiar machines move, sometimes autonomously, but they are certainly not alive.

Growth

• Living things grow by chemically transforming material that is unlike themselves and reorganizing it to add to their own structures. Plants use water and carbon dioxide to make cellulose, and animals consume organic matter that they digest to build their cells. In a roughly comparable way, organic sugar crystals in a liquid suspension grow in size and combine in a complex geometric structure.

Reproduction

• All living things are able to reproduce. Single-cell organisms do this by separating and making exact copies of themselves, while more complex plants and animals engage in sexual reproduction. In both cases, they leave offspring behind after they cease to exist. Fire seems to have a number of the characteristics of living things, including its ability to reproduce itself by spawning additional flames.

Responsiveness

• Animals have organs that allow them to detect and respond to environmental changes. Plants also sense and react to changes in their surroundings. Both modify their behavior or characteristics if there are changes in the external conditions that affect them. Viruses are a curious class of objects that have a number of living characteristics, but scientists no longer consider them to be alive. Viruses do, however, change their characteristics when present in a living host to infect it.