1. Characteristics of Living Things

2. How do you know if something is alive?
All living things…
Are made up of units called cells
Reproduce
Are based on a universal genetic code
Grow and develop
Obtain and use materials and energy
Respond to the environment
Maintain a stable internal environment
As a group, living things change over time

3. What is a cell?
A collection of living matter enclosed by a barrier that separates the cell from its surrounding.
Cells are the smallest units of an organism that can be considered alive.
Unicellular = one cell
Multi-cellular = many cells

4. Reproduction Producing new organisms
Sexual reproduction= cells from 2 different parents unite to produce the first cell of the new organism.
Asexual reproduction= the new organism has a single parent

5. Based on a Genetic code
Offspring resemble their parents because they inherited traits from their parents.
The directions for inheritance are carried on DNA.
This genetic code determines the inherited traits of every organism on earth.

6. Growth and Development
All organisms grow during at least part of their lives
Single celled organisms simply grow in size
Multi-cellular organisms grow by development.

7. Need for materials and energy
Organisms use energy and materials to grow and stay alive
Metabolism = the combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes

8. Response to the environment
Organisms detect and respond to stimuli from their environment.
Stimulus = a signal to which an organism responds

9. Maintaining internal balance
Even though conditions in the external environment vary, most organism must keep internal conditions fairly constant to survive
Homeostasis = maintaining internal stability.

10. Evolution A group of organisms will change over time
As the environment changes a group of organism will change to adapt through the passing of traits from one generation to the next generation