231 KiB
231 KiB
G11 Pre-AP Biology
Cell Theory
- All living things made up of one or more cells
- Basic unit of life
- Comes from preexisting cells
Unicellular vs Multicellular
Unicellular cells are made up of one cell, multicellular cells have more.
Cells
- All cells have:
- Cell membrane
- Cytoplasm
- DNA
- Ribosomes
- Cytoskeleton
Eukaryotic vs Prokaryotic Cells
Eukaryotic Cell
Prokaryotic Cell
| Prokaryotic | Eukaryotic |
|---|---|
| Before the nucleus |
True nucleus/true kernal |
| Between 1-10 µm | Between 100-1000µm |
| Circular DNA (found in nucleoid region) | DNA is linear |
| No membrane bound organelles (compartmentalization) | Membrane bound organelles |
| Reproduces through binary fission | Cell division (Mitosis) |
| Exchanges information with other cells through conjugation | Genetic variation through meiosis |
Endosymbiotic theory
Theory that eukaryotic cells evolved from symbiotic theory between 2 or more prokaryotic cells. Larger cell engulfed a smaller cell, engulfed cell (endosymbiont) became an internal part of engulfing cell (host cell). Mitochondria and chloroplast originated from bacteria.
Ancestral prokaryote engulfed aerobic bacterium. Lived symbiotically. Other ancestral prokaryotes engulfed photosynthetic bacterium. Lived symbiotically.
Evidence:
- Mitochondria and chloroplast have a outer and inner membrane, theorized one from new, one from when it was independent.
- M and C have their own DNA.
- M and C can divide on their own independent of host cell.