1. Characteristics of Living Things:

2. Living things: 4. use energy 5. respond to their environment
1. can reproduce either sexually (2 parents) or 1 parent (asexually)
2. can grow and develop ( not just bigger, also more complex)
3. have similar chemicals – water, carbohydrates, proteins
4. use energy
5. respond to their environment
6. are made of one or more CELLS

4. Where do living things come from?
Other living things!!!
For hundreds of years, it was believed that living things could sometimes come from non-living things:
Ex: mice were created by a pile of straw
Maggots are created by a chunk of rotting meat
This belief was called:
SPONTANEOUS GENERATION

5. Francesco Redi (mid-1600’s) conducted one of the first controlled experiments in order to disprove this theory.

6. OPEN NETTING CLOSED
Jar 1 Jar 2 Jar 3 B E F O R E

7. What did he learn?
The maggots only appeared if they could land on the meat (open jar)
or if they could smell the meat inside (netting).
Living maggots only came from living flies.

8. http://player. discoveryeducation. com/index. cfm

9. Cell theory 1. all known living things are made up of cells.
2. Cells are the basic unit of structure & function
3. all cells come from other living cells

10. Robert Hooke
English Scientist, discovered cells while looking at a thin slice of cork.
He described the cells as tiny boxes or a honeycomb
He thought that cells only existed in plants
and fungi
** named the tiny spaces cell

11. Anton Van Leeuwenhoek 1660’s
Used a handmade microscope to observe pond scum & discovered single-celled organisms **** first to see bacteria
Leeuwenhoek's microscope consisted simply of:
A) a screw for adjusting the height of the object being examined
B) a metal plate serving as the body
C) a skewer to impale the object and rotate it
D) the lens itself, which was spherical

12. Schleiden and Schwann 1830’s
Schleiden: German Botanist, concluded that all plant parts are made of cells
Schwann: German physiologist, who was a close friend of Schleiden, stated that all animal tissues are composed of cells.

13. Rudolf Virchow,1858
German physician, concluded that cells must arise from preexisting cells.

14. The 3 Basic Components of the Cell Theory were now complete:
1. All organisms are composed of one or more cells. (Schleiden & Schwann)( )
2. The cell is the basic unit of life in all living things. (Schleiden & Schwann)( )
3. All cells are produced by the division of preexisting cells. (Virchow)(1858)