CHARACTERISTICS OF LIVING THINGS AIM 3: Develop your foundation for understanding what defines life

What is alive? Organism: a complete living thing. Something that possesses all characteristics of life.

6 characteristics of living things: 1. Reproduction 2. Growth and Development 3. Response to Environment 4. Use Energy 5. Heredity 6. Contain Cell(s)

1. Reproduction Reproduction: an organism must be able to produce offspring and pass along traits Sexual reproduction: two parents involved, offspring are similar to both parents Asexual reproduction: one parent makes identical copies

2. Growth and development Organisms must grow and mature Growth: getting bigger (more mass) Maturation/Development: reaching full functional potential Ex: reproductive abilities, tadpole developing legs

3. Response to environment An organism must be able to respond Not always immediate! Stimulus- anything in the environment that requires an organism to adjust Response- reaction to a stimulus

Movement: Organisms are either sessile or motile

Brainstorm Think of examples of a stimulus and response for the following organisms: 1) humans 2) plants 3) another animal

Response to env. continued… Homeostasis Maintaining a balance between the internal and external environment Examples: Even though external environment changes – organisms want to remain constant

Response to env. continued… Adaptation: a trait that allows an organism to better survive in its environment. Adaptation leads to evolution over time.

4. Use energy All living things need energy to carry out life’s activities Metabolism: all the chemical reactions that happen in an organism. Cellular respiration: process where cells make energy.

Energy continued… Autotrophs: organisms that make their own food Heterotrophs: organisms that consume other organisms

Energy continued… Not all organisms “BREATHE!” but we all must respire Respiration: transport of oxygen from the outside air to the cells within tissues 2 kinds: 1. Anaerobic respiration: WITHOUT oxygen 2. Aerobic: requires oxygen

5.Heredity Heredity: process where genetic information (DNA) is transferred from parent to offspring

6. Made of cells Cells: the basic unit of life. All living things are made up of one or more cells. UNIcellular- organism made up of ONE cell MULTIcellular- organism made up of 2 or more cells