1. Organisms (Characteristics & Needs) Study Pack #2

2. Characteristics of Organisms
Cellular Organization
Contain similar chemicals
Use energy
Grow and develop
Respond to their surroundings
Reproduce

3. Cellular Organization
All organisms are made of small building blocks called cells
Cells are very small – so small you need a microscope to see them

4. Cellular Organization
Organisms may contain one cell or many cells
Unicellular – single-celled organisms like bacteria
Multicellular – composed of many cells each with special jobs

5. Contain Similar Chemicals
The cells of living things contain many chemicals
Water
Carbohydrates for energy
Lipids and proteins for building materials
Nucleic acids for chemical instructions

6. Energy Use Your cells constantly use energy to do certain jobs
For example:
Your eye and brain cells are busy as you read
Your stomach and intestine cells are digesting food
Your blood cells are moving chemicals around your body

7. Growth and Development
Energy is used for an organism to become more complex over time
Organisms use energy to create new cells
Other objects may grow and change over time but they do not become more complex – this is development

8. Response to Surroundings
A change in an organism’s environment that causes it to react is called a stimulus
Stimuli include changes in:
Temperature
Light
Sound
others

9. Response to Surroundings
Stimulus – change in the environment
Response – an action or change in behavior
For example : Consider your response to the stimulus of a loud noise
Non-living things such as rocks do not react to such stimuli

10. Reproduction
To produce offspring similar to the parent
Asexual
Sexual

11. The Needs of Organisms Energy Water Living Space
Stable Internal Conditions

12. Energy Where do you get your energy?
Organisms use food as their energy source
Organisms differ in how they get their energy

13. Energy
For example: Plants capture the sun’s energy and use it along with other materials to make their own food
Autotrophs are organisms that make their own food
auto means “self”
troph means “feeder”
For example: plants

14. Energy Heterotrophs are organism that cannot make their own food
Hetero means “other”
For example: humans
We also get our energy from the sun, but indirectly
We consume autotrophs (plants) or we consumer other heterotrophs that consume autotrophs (cows)

15. Water
Organisms need water to get chemicals from their surrounding, break down foods, grow, move substances around the body, and reproduce
Water makes up 92% of your blood which carries oxygen and food to your cells
Cells also contain water that chemicals are dissolved in

16. Living Space
All organisms need a place to get food and water and find shelter
Sometimes organisms must compete for this space

17. Stable Internal Conditions
Because their outside environments can constantly change, organisms must be able to keep environments inside their bodies constant

18. Stable Internal Conditions
The ability to keep stable internal conditions even though surroundings are constantly changing is called homeostasis
For example, the way your body maintains a certain temperature

19. Let’s see what you know…
True or False
All living things are made up of cells.
A response is a change in an organism’s environment.
Plants are one example of heterotrophs.
All organisms must have water.

20. Homework
Revisit the open response question from yesterday with your new information.