Cells: Cell Theory and Prokaryotic and Eukaryotic Cells.ppt

Cell Theory and Prokaryotic and Eukaryotic Cells

1. Cells

2. First, what is a cell?!
•Cells are smallest unit of life.
•Discovered by Robert Hooke in 1665 using
microscope.
•Every thing we know about cells we call
“cell theory”.
–Developed in 1838 by observations of Schleiden and
Schwann

3. Cell Theory says that….
1.All living things are made of one or more
cells.
2. Cells are the basic units of structure and
function in all living things. In other words,
cells are like the building blocks of all living
things.
3. New cells are only made from existing cells.

4. Cells are the basic unit of life
Cells are the smallest thing that have all of the characteristics of life.
•Organization – cells are made up of smaller parts called organelles which are
made up of compounds & atoms
•Energy Use – cells use chemical energy to function
•Growth – cells get bigger in size and develop specialized structures (example:
flagella are tail-like structures used for movement)
•Response/Adaptation – cells react to stimuli in order to maintain homeostasis
(example: skin cells produce a dark pigment for protection in response to sun
exposure)
•Reproduce – cells divide to create more cells
organization
energy
growth
response
reproduction

5. Cells come in all shapes and sizes!

6. All living things are composed of one or more
cells
•Unicellular – organisms that are only 1 cell
(examples: bacteria, protists, and some fungus)
•Multicellular – organisms made up of 2 or more
cells (plants, animals, and most fungus)
bacteria protist
plant animal fungus
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7. All cells come from other cells
•One of the characteristics of life is to
reproduce, which cells do to make more of
themselves.
•Hair cells make more hair cells, skin cells make
more skin cells, bacteria cells make more
bacteria cells, etc.
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8. There are two types of cells:

9. These are two distinct types of cells with
STRUCTURAL differences.
Prokaryotes
Bacteria
Eukaryotes
Animal Plant

11. Traits of Prokaryotes:
(pro-care-ee-ohts)

13. Bacteria can be harmful or helpful

14. Eukaryote Cell
A more complex cell with
a nucleus and many
organelles.

15. Traits of Eukaryotes:
(you-care-ee-othts)
1. They all have a nucleus where the
genetic material of the cell is stored.
2. They have many organelles that work
together doing specific jobs to help the
cell function.

16. More traits of Eukaryotes:
(you-care-ee-othts)
4.They can be just one cell (unicellular) or can make
up more complex multi-cellular organisms.
5.Some have cilia -hair-like structures that protrude
from some eukaryotic cells.
–enables some cells to move through their environment.
–On other cells helps substances across their
surfaces.
•ex. cells of human respiratory.
6. All plants, animals, fungi, and protists are
eukaryotic cells.