Which of the following is a characteristic of living organisms?

Reproduction and growth are fundamental characteristics of living organisms. This ability to reproduce ensures the continuation of a species, while growth is a vital process in which organisms increase in size and complexity over time. Living organisms have specific biological processes that allow them to develop from a single cell into more complex forms, adapting and evolving in response to their environments. This characteristic distinguishes them from non-living things and highlights the dynamic nature of life.

The other options do not accurately encompass the essential characteristics of all living organisms. For example, while some organisms are made of tissues, not all, such as unicellular organisms, share this trait. The idea of spontaneous generation is a discredited theory; living organisms arise from pre-existing life, not randomly. Furthermore, the notion that organisms can only live in water excludes many terrestrial organisms and thus does not apply universally. Therefore, reproduction and growth are key traits that define the essence of all living beings.