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Cellular Reproduction

Cellular Reproduction. A Brief History of Genetics Before Mendel Major Discoveries Circa World War I History of Discovery of Cells Evolution and Diversity of Cells Architecture of Cells 1/2.

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Cellular Reproduction

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  1. Cellular Reproduction A Brief History of Genetics Before Mendel Major Discoveries Circa World War I History of Discovery of Cells Evolution and Diversity of Cells Architecture of Cells 1/2

  2. Hippocrates (400 BC): traits are inherited from parents; reproductive products are obtained from all body parts and given to the offspring • Example: Macrocephali: species of humans w/ elongated head; Hippocrates believed they styled their offspring’s head soon after birth • Aristotle (350 BC): differed from Hippocrates due to the inheritance of nails, hair, voice; did not believe it came from reproductive tissue because they were dead cells; based on the fact offspring sometimes resemble grandparents, he believed “reproductive material” was obtained from “nutrient substances” (semen from the father, originates from blood) designed specifically for a part; believed females had something that defined the “form of the embryo” • Both Hippocrates & Aristotle believed trait inheritance was through reproductive material • Al-Jahiz (800s CE): proposed a theory of animal evolution through natural selection (environmental effects) • Abu Alkasem Al Zehrawi (Albucasis) (936 CE): described the genetic disorders in blood, now known as hemophilia • Otto Brunfels (1488-1534): adopted ancient classification of plants, interested in medical advantages of botany, keep records of his plants, considered “link between ancient and modern botany” History of Genetics Before Mendel

  3. Hieronymus Brock (1498-1554): studied German plants, recorded them based on relation, resemblance, & medical use • Leonhart Fuchs (1501-1566): wrote book accurately classifying around 500 plants and their medical uses • Andrea Cesalpino (1524-1603): classified plants based on principles (fruits/seeds) not alphabetically or medical usage; established botany; believed plants were not sexual & divided plants by woody/herbaceous • GaspardBauhin (1560-1624): botanical classification, 6000 species of plants, classified between genus and species, “introduced binomial nomenclature system” • Species of plant receives a name of two terms: 1st is the genus, 2nd is the species • John Ray (1627-1705): classified 18000+ plants in a natural system (reflection of Divine Order); morphology (flowers, seeds…); monocots & dicots (classification of flowers), used term “species” • Joseph Pitton de Tournefort (1656-1708): classification of genera (structure of flower & fruit); didn’t believe in sexual reproduction of plants; used 2 word Latin name for plants; defined genus for future times (own classifications were often wrong) • Carl Linnaeus (1707-1778): defined the princples for natural genera & species of organisms, established a uniform system (binomial nomenclature); presented hierarchical classification (taxonomy) • AugustinSagaret (1763-1851): crossed plants of a particular trait, usually got that same trait (appearance) History of Genetics Before Mendel

  4. 300s BC: Hippocrates-heredity material, throughout body 200s BC: Aristotle- material gained from semen (purified form of blood which mixed w/ the mother's menstrual blood) 800s CE: Al-Jahiz-inheritance of acquired characteristics, environmental factors influence organisms to develop new characteristics to ensure survival, thus transforming into new species." 1700s: increased taxonomy & diversity of plant/animal species, new ideas about heredity 1800s: crossing certain parent plants, particular characteristic, usually led to the appearance of the characteristic in the offspring 1859: Charles Darwin-The Origin of Species, evolution by natural selection; needed genetic inheritance 1866: Gregor Mendel-Experiments in Plant Hybridization, basic theory of genetics 1871: Friedrich Miescher- isolates “nucleic acid” whilst trying to wash the puss off dirty bandages at a local hospital 1879: Walther Flemming- discovers chromosomes using aniline dyes History of Genetics Before Mendel

  5. 1900: August Weismann-proposed inheritance takes place through germ cells 1902: Theodor Boveri (sea urchins) and Walter Sutton (grasshoppers) hereditary material is carried in chromosomes: firstly, all the chromosomes had to be present for proper embryonic development to take place; chromosomes occur in matched pairs of maternal and paternal chromosomes which separate during meiosis 1902: Archibald Garrod-recessive inheritance in humans 1910: Thomas Hunt Morgan- chromosome theory of heredity using the fruit fly; genes are linked in a series on chromosomes, responsible for hereditary traits 1919: Phoebus Levene-identified units of DNA which he calls "nucleotides". (base, a pentose sugar, & a phosphate group); hypothesis DNA structure: chains short & bases repeated 1928: Frederick Griffith- discovers harmless strain of bacteria could be dangerous after being exposed to heat; some kind of substance ("transforming principle") from the heat-killed strain was taken up & incorporated in the harmless strain, making them virulent 1937: William Astbury-X-ray diffraction patterns revealing DNA has a regular structure Major Discoveries Circa WWI

  6. Zymotechnology • Study of fermentation (breakdown of carbohydrates) • Initially focused on beer…WWI, focused on industrial problems • Due to industrial support of war -> massive production • Later called, biotechnology (1919)- “convert raw materials into a useful product” • Possible solutions for food and resource shortages • http://www.lifesciencesfoundation.org/events-item-111.html • http://www.spartacus.schoolnet.co.uk/FWWinventors.htm Major Discoveries Circa WWI

  7. Eugenics: • Refer to the “science of heredity” • Eugenic groups appeared after WWI due to fear of immigration (foreigners) • Race Betterment Foundation • American Eugenic Society (1923) • Promoted fine breeding • Discouraged maintaining people w/ undesirable traits with others • Banned reproducing (if allowed) • Attained some goals- Immigration Act (1924) passed by Congress, limited immigration through quotas, signed by President Coolidge • Behaviorism (1913) & Thomas Hunt Morgan’s genetic work helped reduced focus on eugenics • WWII-German actions on Jew completely disbanded the movement Major Discoveries Circa WWI

  8. Rise in industrialism & mass production • Warfare technology • Wireless telegraphy, radio, telephone (often broken); used runners, mirrors, flashing lights, dogs, aircraft , microphones • Naval Warfare • Germany & Britain • Britain built HMS Dreadnaught, revolutionized ship building • Submarine: caused the US to enter the war (Germany attacked 1917) • Armaments, Supplies • Hand grenades & explosives: trench warfare • Barbed Wire: invented in 1874 to control cattle, was used to fence trenches, troops would get tangled which permitted machine gun usage • Machine guns (replaced Gatling guns), allowed quick, rapid shooting l flame throwers (used by Germany) • Airplanes: invented 11 yrs prior to the war; two alliances would deny the other air advantage – coined Flying Circus • Red Baron: Manfred von Richthofen: pilot, shot down 80 planes • Germany: Zeppelins (bombing raids) • Observation Balloons: crew of 2, observed trenches • Tanks: Allies (1915-16, 1917-used), not as decisive, helped win the Allied summer offensive of 1918 • Poison gas: used by Germany to stop “stalemate of trench warfare,” effects were fatal, wasn’t as utilized after 1916 • Railroads aided in the transport of artillery & troops Major Discoveries Circa WWI

  9. Cell: structural, functional, and biological unit of all organisms • Organisms: all living things • Unicellular: has one cell • Cytology: study of cells • Organelles: small structure inside a cell • Prokaryotic Cells: simplest type of cell, unicellular, most have a cell wall, asexual (reproduce through binary fission) • Eukaryotic Cells: complex type of cell, more organelles than prokaryotes, most are multicellular, undergo a process called differentiation Vocabulary

  10. Democritus (460 BC) • All things are composed of “minute, invisible particles of pure matter” • Hans & Zacharias Jansen (1590) • Created the early version of the compound microscope • Robert Hooke (1665) • Described the composition of cork through a compound microscope: “tiny, hollow, room-like structures,” called them cells (were in actuality cell walls) • Anton van Leeuwenhoek (1670) • Improved lenses (allowed magnification), observed blood, rain, teeth scraping, called some cells “animalcules” (bacteria) CELL THEORY • Matthias Schleiden (1838) • Observed plant parts, discovered they were made of cells • Theodor Schwann (1839) • Observed animal parts, made of cells Important Figures • Rudolph Virchow (1855) • All living cells come from other living cells

  11. Caspar Wolff (1759) • All organs in animal embryos are made of “globules” • Felice Fontana (1781) • Described nucleolus, found in eel’s skin’s slime • Jean Baptiste de Lamarck (1809) • Declared that cellular tissue is the “general matrix of all organization” • Henri Dutrochet (1824) • All organic tissue is globular cells • Pierre Turpin (1826) • Observations on cell division • Franz Meyen (1830) • Cells form independent whole, which then builds itself up • Robert Brown (1831) • Discoveries of occurrence of nuclei • Hugo von Mohl (1839) • Described mitosis in plants • Gregor Mendel • Plant hybrids, genetics Important Figures • Anton Schneider (1873) • Observations of chromosomes during cell division

  12. Discoveries of Hooke, Schleiden, and Virchow helped the formation of the theory • Improvement in microscopy permitted these discoveries • Consists of three parts • Anything living is made up of cells • Chemical reactions inside an organism occur in cells • All cells come from preexisting cells • http://youtu.be/4OpBylwH9DU • http://youtu.be/h85_U9OJFQ0 Cell Theory

  13. 1. All known living things are made up of cells. 2. The cell is structural & functional unit of all living things. 3. All cells come from pre-existing cells by division. (Spontaneous Generation does not occur) 4. Cells contains hereditary information which is passed from cell to cell during cell division. 5. All cells are basically the same in chemical composition. 6. All energy flow (metabolism & biochemistry) of life occurs within cells. Modern Cell Theory

  14. Diversity in molecular compositions • Secondary cells walls, reinforced with lignin-provides durability • Some have pollen tubes that enable their tip growth • Lupin seed cell walls are thicker due to galactan, a storage polysaccharide • Dependent on developmental stage, cell type, and season. • Plants & algae: phylogenetic history, endosymbiotic events; “organisms that have the shared features of photosynthesis and possession of a cell wall do not form a monophyletic group” • Phylogenetic: study of evolutionary development of organism, higher taxonomic groups • Taxonomy: Classification of organisms based on shared feature • Monophyletic: Descended from a single taxon Cell Evolution: Cell Wall

  15. Endosymbiotic Theory: accepted assumption explaining how eukaryotes evolved from prokaryotes • Introduced by Lynn Margulis in the late 1960s • Stated that the main organelles of eukaryotes were initially prokaryotes • Endosymbiosis: organism lives inside another, mutually beneficial • Organelles proposed to have been their own cell include the mitochondria and chloroplast • Both organelles have their own DNA & ribosomes that do “not match” the rest of the cell • Because of this, they can survive & reproduce independently • Chloroplast DNA is alike to cyanobacteria • Mitochondria DNA is alike to typhus bacteria Cell Evolution: Endosymbiotic Theory

  16. Prokaryotes Eukaryotes Animal Plant Bacteria Prokaryotes vs. Eukaryotes

  17. Prokaryotes vs. Eukaryotes

  18. Prokaryote: single celled organism w/ no nucleus, lack internal membranes • Plasma Membrane: around cytoplasm, regulates flow of substances in & out of cell • Cytoplasm: Gel-like substance that is made of mostly water & enzymes, salts, cell components, & organic molecules • Nucleoid Region: area of cytoplasm that contains the single bacterial DNA molecule • Ribosomes: responsible for protein production • Plasmids: Gene carrying, circular DNA structures (not involved in reproduction) • Cell Wall: outer covering, protects, & gives cells their shape • Suface Appendages: • Pili: hair-like structures that attach to other bacterial cells • Fimbriae: shorter pili, help bacteria attach to surface • Flagella: long, whip-like protrusion that aids in cellular locomotion • Cellular Locomotion: http://www.youtube.com/watch?v=Jt1oMaxrp3U • Capsule: outer covering protecting the cells when it is swallowed by other organisms, retains moisture, and helps cell hold on to surfaces & nutrients • http://www.vetmed.vt.edu/education/curriculum/vm8054/Labs/Lab3/Lab3.htm Cell Structures in Prokaryotes

  19. Plasma Membrane: thin, semi-permeable membrane that surrounds cytoplasm of a cell, enclosing its contents • http://www.youtube.com/watch?feature=player_embedded&v=Mv247P8ufCA • Cytoplasm: gel-like substance within the cell containing water, enzymes, salts, organelles • Cell Wall: outer covering of the cell that protects the plant cell and gives it shape • Nucleus: membrane bound structure that contains the cell’s hereditary information • Nucleolus: structure w/in the nucleus, helps in synthesis of ribosomes, RNA • Nucleopore: tiny hole within nuclear membrane that allows nucleic acids and protein to move into & out of the nucleus • Extracellular Matrix: support, adhesion, movement, and cell regulation • Chromatin: chromosomes DNA and protein • Nuclear Envelope: ER, golgiapparaturs, vacuoles, plasma membrane • Ribosome: consist of RNA & protein, responsible for protein assembly • Rough Endoplasmic Reticulum: synthesis & packing of proteins • Smooth Endoplasmic Reticulum: storage of steroids and ions • Golgi Apparatus: responsible for manufacturing, storing, & shipping certain cellular products • Lysosomes: sacs of hydrolytic enzymes that digest cellular macromolecules such as nucleic acids • Vesicles: small, contains proteins, enclosed by phospholipids layers • Centrioles: organize the assembly of microtubules during cell division Cell Structures in Eukaryotes

  20. Mitochondria: power producers and the sites of cellular respiration • Microtubules: hollow rods that function to help support & shape cells • Chloroplasts: sites of photosynthesis in a plant cell, contain chlorophyll (green pigment that absorbs energy from the sunlight) • Central Vacuoles: structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth • Peroxisomes: tiny structures bound by a single membrane that contain oxidative enzymes that produce hydrogen peroxide as a byproduct, help in photorespiration • Centrosomes: contains microtubules, as centrioles, regulator of “cell-cycle” • Cilia & Flagella: protrusions that aid in cellular locomotion • Cytoskeletal Elements: network of fibers in the cytoplasm that helps the cell maintain its shape • Microtubules: hollow rods, help support and shape cell, “routes” along which organelles can move, responsible for chromosome movement in cell division, movement of organelles • Microfilaments/Actin Filaments: solid rods, help in muscle contraction, cell division, maintenance of cell shape • Intermediate Filaments: provide support for microfilaments and microtubules by holding them in position, anchor nucleus, forms nuclear lamina • Endomembrane System: contains different membranes in the cytoplasm, divide the cell into organelles Cell Structures in Eukaryotes

  21. Nucleus: control center & location for genetic information replication (contains DNA), DNA binds to proteins (histones) & form nucleosomes; RNA is obtained from DNA & interpreted • Centrosomes: microtubules are produced, contains centrioles; cell division-centrosome divides & centrioles replicate resulting in 2 centrosomes w/ centrioles, they move to opposite side of nucleus where microtubules become a spindle • Spindle: separates replicated chromosomes into the daughter cells • Microtubules: form spindle fibers, manipulate & separate chromosomes during mitosis • Cell Membrane: closes and splits the cell into two daughter cells (telophase during mitosis) • Cell Wall: splits in half when the daughter cells divide Subcellular Organelles Involved in Cell Reproduction

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