BIOL 206 Lecture Notes - Lecture 5: Spindle Apparatus, Golgi Apparatus, Endoplasmic Reticulum
Document Summary
Multicellular eukaryotes are united by common cellular features: flexible cell surface. Allows for sufficient surface area:volume ratio as size increased. Not unique to eukaryotes: complex and extensive cytoskeleton: Intracellular movement: nuclear envelope and endomembrane system. Plasma membrane: digestive vacuoles for intracellular digestion aka lysosomes in animal cells, organelle(s) acquired via endosymbiosis. Plants are sessile organisms, whereas animals are motile. Phylogeny of land plants: land plants evolved ~500 million years ago, as descendants of multicellular green algae that colonized land. Evolutionary innovations in land plants: adaptations to a terrestrial environment. Size matters when competing for resources: plant vascular tissues: Transition to non-motile sperm cells & new forms of pollen dispersal. Enable a large, branching body: however, this collection of energy nutrients also allowed other organisms to colonize the terrestrial environment. Phylogeny of animals: fungi, choanoflagellates and animals probably share a common ancestor.
