Endosymbiotic Theory for the Evolution of Eukaryotic Cells The theory that eukaryotic cells arose from a symbiotic relationship formed when a _____________________________ ________________________________. A mutually beneficial relationship evolved into membrane-bound organelles.

Endo = in Symbiosis= a close relationship between species

Supporting Evidence Mitochondria and chloroplasts ____________ ______________, which is a circular chromosome similar to prokaryotic cell chromosomes. Mitochondria have their own ribosomes which are

similar to prokaryotic ribosomes. Mitochondria and chloroplasts can divide on their

own.

Supporting Evidence Cont. Mitochondria and chloroplasts are surrounded by a __________________________ (as would be a cell engulfed by another cell.) Mitochondria and chloroplasts are the same size as a typical prokaryotic cell.

Video: Endosymbiotic Theory http://w

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Review with your table partner:

Discuss with your partner anything you have already learned about how viruses compare to cells.

Virus Bacterium (Prokaryotic Cell) Eukaryotic Cell

• _______________ ____________ • Protein Coat • Does NOT contain

ribosomes

• DNA (not separated from cell)

• Cell Membrane • Ribosomes • Enzymes

• DNA is in nucleus • Membrane-bound

organelles with enzymes for each task organized

• _____________________________________________

• Can NOT produce ATP (utilize energy)

• Can produce proteins

• Can produce ATP from an energy source

• More efficient • Can be 10-100 x

bigger than a bacterium

Viruses must ____________________________.

http://learn.genetics.utah.edu/content/begin/cells/scale/

Relative Sizes of Cells, Organelles, Viruses, Molecules and Atoms:

Unicellular:

An organism made of only one cell.

Example: Diatom

Multicellular:

An organisms made of many cells.

The average human has approximately 100 trillion cells.

Levels of Organization

Tissue: A group of __________ cells that work together.

Example: Muscle tissue

Organ: A group of __________ types of cells that work together for a specific function.

Example: The heart

Organ System: A group of organs that work together.

Example: The circulatory system