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Besides animals: Plant & bacteria cells Prokaryotes • Prokaryotes: Bacteria – Pro: “Before” + Karyon: “Kernel” i.e. a nucleus • Has DNA, but not wrapped up in a membrane – Often 1 double stranded DNA looped in a coil • Short generation time means lots of chances to change DNA E. Coli for example • 4 million B.P. & 3000 genes – 100xs more than a virus, 0.001x’s that of a eukaryote – Stretched out that’s about a mm in length, 500 times longer than the cell. – Imagine eating a strand of spaghetti 3000 feet long – Also lots of plasmids floating around • About 1 or 2 genes on those • Double grains of rice on each square on a chess board • You have more ancestors than the population of the world • We’re all a little inbred • Cheetahs and limited genetic variation • All genetically similar • Seldom reject donor organs • ~12,500 left in the wild • Leaves little room for chance • If one is vulnerable to a disease, unlikely to be a resistant mutant E. Coli: Binary fission causes them to double every 20 minutes Go from 1 108 over night What does this have to do with me? We lose 2 x 1010 E. Coli every day, but they grow fast. It keeps the sanitary authority busy. Harry Readshaw chairman of ALCOSAN Rapid generations • Binary fission: Asexual, – Offspring are genetically identical to parents • But combine small chance of mutation with large large numbers of offspring and you get a couple mutants every day • Compare to slow-reproducing organisms who don’t get mutants that often. Plant Cells • Like animals – Plasma membrane,Nucleus, Ribosomes,ER,Golgi,Mitochondria,Peroxisomes, microtubules • Unlike animals – Plastids – Chloroplast photosynthesis – Vacuole stores chemicals – Cell Wall maintain shape, protection Cell Wall component: Lignin • Derived from a.a. phenylalanine • One of the most abundant biomolecules on Earth after – Cellulose & Chitin – ~1/4 the mass of dry wood • Effective barrier against invaders • Hydrophobic, plants use it to channel water • Have to remove it before we get paper • Burn it to get smoked flavor Elodea cells Elodea • Genus of plants: “the water weeds” • Native to N. America • Invasive to everywhere else • Can grow unrooted • Good aquarium plant • Good habitat • Ducks & beaver eat it • Iroquois used as a drug • Say that box is 1 mm across • If 6 elodea cells fit across the box how long is 1 elodea cell? • If ~14 elodea cells fit up and down the box about how wide is an elodea cell? You got math in my science! • Assume the cell is as high as it is wide. • Now you have the length, width, & height of an elodea cell. • Figure out the volume: L x W x H