Characteristics of Living Things How do we know if something is alive?

Characteristics of Living Things All living things must be able to obtain and use energy. All living things must be able to reproduce. All living things must be able to respond and adapt to their environment. All living things must be able to grow and develop. All living things must be composed of cells (or be a cell).

Classifying Living Things When we study different aspects of living things, we tend to classify them based on their complexity. Place the following in increasing order of complexity: Cell Organ Organ System Organism Tissue

Cell Most basic unit of life.

Tissue Groups of cells clustered together.

Organ Collections of tissue with similar functions.

Organ System Several organs working together to perform a certain function.

Organism You!

Types of Cells