introduction to cells - biology for life · introduction to cells . the cell theory –all...
TRANSCRIPT
The cell theory
– The cell is the basic unit of life • Even unicellular organisms carry out all
the functions of life
Evidence for the Cell Theory
Read this short summary of evidence for the
cell theory.
Organization is basically similar in all cells
• All cells have a cell membrane which is a selective barrier – Lets some materials in /
out of the cell
– Prevents other materials from coming in / out
Organization is basically similar in all cells
– Internally, all cells contain • Cytoplasm
• Ribosomes
• A region that contains DNA
There are two main types of cells: Prokaryotic Bacteria Archaea
Eukaryotic Protist Plants Fungi Animals
Bacteria have prokaryotic cells:
• No true nucleus
• Unicellular
• 2 types: – Eubacteria (true
bacteria)
– Archaea bacteria
Eukaryotic cells contain organelles
• An organelle is a discrete structure within a cell that has a specific function
• Organelles are covered by their own membrane.
Cells work together in organisms that contain more than one cell
• A tissue is an integrated group of cells that
have a common structure and function.
TISSUE
Each level of biological organization
exhibits emergent properties (click link)
Ex.
Capillaries
transport
blood (property not
exhibited by
individual
endothelial
cells).
The cells of a multicellular organism differentiate to carry out specialized functions by only expressing some of their genes.
Cells in multicellular organisms differentiate (click link to read what this means!)