Final answer:
The hierarchy of life organizes biological complexity from the simple to the most encompassing, beginning with the cell which is the first level considered living.
Step-by-step explanation:
The hierarchy of life is a way to organize the biological world by levels of complexity. The concept is structured around the idea that life starts with small, basic elements and evolves into more complex structures. The first level within this hierarchy that is considered living is the cell. Cells are the basic unit of life, capable of performing all life processes, and they make up all living organisms.
All living organisms share key characteristics: order, sensitivity to the environment, reproduction, adaptation, growth and development, homeostasis, energy processing, and evolution. These characteristics help to define an organism's structure at different levels of organization.
- Oxygen atom - A basic unit of matter.
- Water molecule - Atoms bonded together to form molecules, which are not alive.
- Skin cell - The basic unit of living organisms, where life begins.
- Liver - A collection of tissues arranged into an organ.
- Elephant - An individual organism, a complex structure of cells.
- Wolf pack - A group of organisms of the same species living and interacting together.
- Tropical rainforest - An ecosystem, a community of living organisms with their environment.
- Planet Earth - Encompasses all levels of biological organization, including the biosphere.
These classifications are placed in the hierarchy based on increasing complexity and interconnectivity, where each higher level encompasses the sum of its parts along with added complexities.