1. What’s Life? 1

2. Where Does Life Come From?
We already learned that life doesn’t just “appear” out of thin air!
Spontaneous Generation
Remember Francesco Redi???
What was his experiment???
A controlled experiment with meat and maggots!

3. Redi's Hypothesis
Redi made a prediction that keeping flies away from meat would prevent the appearance of maggots
To test this hypothesis, he set up an experiment: 3

4. But, what does it even MEAN to be ALIVE????
So?
He set up a controlled experiment to prove that life comes from life...
(That's important! You'll need to know that later!)
But, what does it even MEAN to be ALIVE???? 4

5. Is It Alive? How do we know when something is alive?
The world is made up of many different things.
Some things, like plants and animals, are
living.
Biotic
Other things, like cars and rocks are
non-living.
Abiotic
Living things are called *organisms* 5

6. Again… How do we know something is ALIVE?
What’s the difference between ALIVE and DEAD and NON-LIVING?

7. It's ALIVE!!!!
it's alive! 7

8. Living or Non-living? STRANGER-C
You know plants and animals are living things.
How do you know this?
All living things (YES, ALL LIVING THINGS) have certain characteristics in common.
We will remember them by remembering THIS phrase:
STRANGER-C 8

9. S T R A N G E R C Synthesis Transport Respiration Adapt/Respond
There are 9 characteristics (processes) of life:
Synthesis
Transport
Respiration
Adapt/Respond
Nutrition
Growth/Genetics
Excretion
Reproduction
Cells What's Life? 9

10. Synthesis Synthesis means to make / build something more complex
Think Legos ! 10

11. Transport Transport means movement
Transportation is the process by which substances enter and leave our cells and become distributed within the cells
Think of water getting from the roots of a tree all the way to the leaves at the top of the branches
Or blood circulating through your body 11

12. Respiration (Not Breathing!)
Cell Respiration the process of changing energy stored in food into a chemical energy (ATP) which cells can use
Two types:
Aerobic – Uses oxygen
Anaerobic – Does not use oxygen
AKA: FERMENTATION 12

13. Adapt/Respond
All living things need to adapt and respond to their environment if they are to survive
Adapting means changing to be better able to survive
Responding means reacting to changes in the environment
Stimulus = any factor (signal) that causes a change/response - it’s a change in the environment which causes a reaction
Doorbell
Phone Ringing
Response = a reaction to a change caused by a stimulus
Goosebumps
Sweat
Know these 2! 13

14. Nutrition
Nutrition means taking in nutrients needed to make energy and survive
Ingest means to take in food
Think of you munching on a Big Mac
Digest means breaking down large “stuff” (complex materials) into smaller/simpler forms
That Big Mac doesn't go sloshing around beneath your skin, smearing ooey-gooey yummy-ness all over your muscles and bones, does it???? 14

15. Growth & Genetics Growth means to increase in size and/or number
Even though we appear to stop growing… we always need new cells to repair/replace old ones!
Genes are necessary for this to happen!
Your GENES are made up of DNA that contains the instructions for the cell (and we'll learn TONS about that later on!)
Genetics is the science of heredity
Heredity means how genes are passed from one generation to another 15

16. Excretion Excretion means to get rid of cellular waste
It’s NOT Poop!
Excretion means to get rid of cellular waste
You excrete in many ways:
Pee-ing (Yup.... I said it!)
Sweat
Ever wonder why the underarm area of your favorite white tee-shirt ends up stained and yellowed???
Breathing
What happens when you breathe on a mirror??? 16

17. Reproduction Reproduction means making more of your own kind
Aka Offspring
Two types:
Asexual – one parent produces offspring which are identical to the parent
Sexual – two parents are required to produce offspring and the organism they produce is not identical to either parent
This is the ONLY life-characteristic that is NOT required for that particular organism to stay alive.... 17

18. CELLS Cells are the building blocks of EVERY living organism
The basic unit of structure and function of all living things
EVERY single cell is actually alive and....
Can exist on it’s own → unicellular
Or work with other cells to make a different organism - → multicellular 18

19. ALL living things NEED certain things to survive:
Needs of Living Things
ALL living things NEED certain things to survive:
ENERGY – The primary source of energy is the SUN
FOOD & WATER – ~70% of your body is water!
AIR – Air is made of the gases which plants and animals need to survive
LIVING SPACE – Living things need a place to get food, water and energy
PROPER TEMPERATURE –The internal temperature must remain in a certain range…. 19

20. Important Words to Know !!!!!
Metabolism = ALL the chemical reactions occurring within an organism
Homeostasis = “Steady State”. Maintaining a stable internal environment (even when the external environment changes!)
- What’s your body temperature???
* Do you think it changes (inside) if it’s super cold outside??? Super hot??? 20