* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Guess who’s coming to dinner? “Plant growth comes about through the production of new cells…propagated from the cytoblasts [nuclei] of old cells” Matthias Schleiden “Once when he was dining with Scheliden in 1837, the conversation turned on the nuclei of vegetable cells. Schwann remembered having seen similar structures in the cells of the notochord and instantly realized the importance of connecting the two phenomena.” Theodor Schwann The Cell Theory All organisms are composed of cells Cells are the smallest living unit of living things The Cell Theory All organisms are composed of cells Cells are the smallest living unit of living things “Omnis cellula e cellula.” * (1855)xxx Rudolf Virchow * “All cells arise from cells” The Cell Theory All organisms are composed of cells Cells are the smallest living unit of living things All cells come from cells Spontaneous generation What is a Theory? Important Scientific Theories Cell theory Germ theory of disease Theory of evolution Atomic theory Heliocentric theory of the solar system Universal gravitation Theory of relativity Quantum theory String theory Linnaeus believed every living thing could be classified as a plant or an animal. What do we believe today is the most fundamental division among living things? Tree of Life The Eukaryotic Cell Nucleus • • • • Genetic material (DNA) Chromatin (chromosomes) Nuclear envelope (with pores) Nucleolus The Prokaryotic Cell Archaea First believed to be bacteria Live in Extreme environments Halobacteria Tree of Life A Survey of Cell types Plasma Cell Makes and secretes antibodies. A Survey of Cell types Paramecium Single cell motile organisms A Survey of Cell types Sperm Cell Need large amounts of energy for tail movement A Survey of Cell types Neuron and Neuronal synapse A Survey of Cell types Intestinal epithelium Absorb nutrients from gut. A Survey of Cell types Is this a cell? If so, what kind of cell? What is the arrrow pointing to? Bonus Cell(s)?: What are the green sphere’s? What is their role for the organism they reside in? What do mitochondria and chloroplasts have in common? The Endosymbiosis Theory Similar in size to prokaryotic cells Two membranes Own DNA Own ribosomes, prokaryote-like Divide independently DNA sequence like prokaryotic genes ancestral cell membrane infolding creates nucleus, ER endosymbiosis results in mitochondria endosymbiosis results in chloroplasts ancestral animal cell ancestral plant cell Why are prokaryotes small and eukaryotes large? Which are more successful: prokaryotes or eukaryotes?