Cell Notes

1 Pages 328 Words

Section 2-1 Review


1. What observations were used to develop the cell theory?
• German botanist, Schleiden – cells compose not only the stems and roots but every part of a plant
• German zoologist, Schwann - made same claim about animals
• German physician, Virchow – observed that cells come only from other cells

2. What function do organelles serve?
• Eukaryotic cells possess organelles
• Their small, specific membrane-bound internal compartments, that carry out specific functions in the cell.

3. Explain why cells must be small.
• 2 limits that affect how efficiently cells work and that govern cell size.
• One is related to the exchange between the inside and the outside of the cell.
- All info and materials entering or leaving the cell must pass through
“doors” in the cell membrane. The efficiency of this exchange depends on the ratio of the cell’s surface area to its volume.
- Large cells have far less membrane surface per unit of volume with which
to supply materials to the cells interior and to rid it of wastes.
• The other reason is that as the cell size increases, it takes longer for information and materials to reach their destination.
• SMALL CELLS ARE MORE EFFICIENT THAN LARGER CELLS.

4. Explain prokaryotes and eukaryotes.
• Prokaryotic cells are single-celled organisms that lack internal membrane-bound compartments.
• Eukaryotic cells are complex cells that have a nucleus and organelles,
• Bacteria is the only prokaryote, all other living cells are eukaryotes.
• Many biologists think that eukaryotes evolved from prokaryotes.

5. The three parts of the cell theory
• All living things are composed of one or more cells.
• In organisms, cells are the basic units of structure and function.
• Cells are produced only from existing cells....