The document introduces the key characteristics that define life, including homeostasis, organization, metabolism, growth, adaptation, response to stimuli, and reproduction. It explains that living things are made of cells that are organized into tissues, organs and organ systems. The key levels of organization in living things are cells, tissues, organs, organ systems and organisms. The document is an introduction to defining the characteristics of life and the levels of organization that make up living things.

1. Introduction to Life

2. What makes something alive?
Life - the condition that distinguishes animals and
plants from inorganic matter.
Living – alive, not dead or lifeless.
Nonliving – inanimate, inactive, not endowed with
life.
These definitions do not tell us what makes
something alive!
So, what are the characteristics of life??

3. Characteristics of Life
1. Homeostasis
2. Organization
3. Metabolism
4. Growth
5. Adaptation
6. Response to stimuli
7. Reproduction

4. Characteristics of Life
● Homeostasis – tendency to maintain a
stable, balanced, internal environment.

5. Characteristics of Life
● Organization – All things are made of one
or more cells.

6. Characteristics of Life
● Metabolism – must transform energy by
converting chemicals & energy into
cellular components.

7. Characteristics of Life
● Growth – Increase in size over time

8. Characteristics of Life
● Adaptation – ability to change over time
in response to the environment.

9. Characteristics of Life
● Response to stimuli – will react to
environmental factors such as heat,
light, and food availability.

10. Characteristics of Life
● Reproduction – ability to produce more
of the same type of organism.

11. Is it living?

12. Is it living?
1. Homeostasis?
2. Organization?
3. Metabolism?
4. Growth?
5. Adaptation?
6. Response to stimuli?
7. Reproduction?

13. Is it living?

14. Is it living?
1. Homeostasis?
2. Organization?
3. Metabolism?
4. Growth?
5. Adaptation?
6. Response to stimuli?
7. Reproduction?

15. Is it living?

16. Is it living?
1. Homeostasis?
2. Organization?
3. Metabolism?
4. Growth?
5. Adaptation?
6. Response to stimuli?
7. Reproduction?

17. Is it living?

18. Is it living?
1. Homeostasis?
2. Organization?
3. Metabolism?
4. Growth?
5. Adaptation?
6. Response to stimuli?
7. Reproduction?

19. Organization
Okay, so now we know how
to tell if something is living
or nonliving…
How is life organized?

21. Cells are the basic building blocks of
living things. They contain organelles
and genetic material.

22. Tissues are groups
of similar cells
organized to work
together.
Examples: epithelial,
muscle, nervous,
and connective.

23. Organs are structures
made up of several
groups of tissues
working together to
perform a specific
function.
Examples: heart,
lungs, brain, skin,
etc.

24. Organ systems are groups of organs
working together to perform a function.
Examples: digestive, cardiovascular,
respiratory, and nervous systems

25. Organisms are living things. Some are
single-celled, others are multicellular.
Frequently they have many organ
systems working together.