Biology 2 Notes PDF

Notes Myiasis- fly larvae feeding on living or dead tissue Facultative myiasis – maggots developing in wounds and ulcers; used to clean out necrotic tissue (maggot therapy) Origins of life – Earth’s formation of crust and oceans (4 to 3.5 billion years ago) Minimal properties of life: - Metaboli...

Notes Myiasis- fly larvae feeding on living or dead tissue Facultative myiasis – maggots developing in wounds and ulcers; used to clean out necrotic tissue (maggot therapy) Origins of life – Earth’s formation of crust and oceans (4 to 3.5 billion years ago) Minimal properties of life: - Metabolism - absorb nutrients and expel waste, use energy - Reproduction - growth, duplicate cells - Evolution – reproduction, mutation Where did the first life come from? How did all the necessary parts of a living cell come together? How can non-living matter evolve? 1) Organic molecules are produced prior to cells 2) Nucleotides and amino acids became polymerized to form DNA, RNA and proteins 3) Polymers became enclosed in membranes 4) Polymers enclosed in membranes acquired cellular properties 1) - Spontaneous formation of organic molecules on early earth - several hypotheses on where and howorganic molecules originated origin of organic molecules - Reducing Atmosphere Hypothesis Atmospheric reactions with lightning, solar and cosmic radiation - Extraterrestrial Hypothesis  On meteorites – organic molecules formed in interstellar clouds - Deep Sea Vent Hypothesis Underwater reactions with volcanic vents Miller-Urey 1952’s EXPERIMENT – atmospheric condition and electrical discharge resulting in spontaneous formation Deep-sea Vent – molecules forming in temperature gradient Extraterrestrial Hypothesis – Meteorites producing organic carbon to earth 2) Organic polymers - formation of nucleic acid polymers & polypeptides on clay surfaces 3) Formation of boundaries - formation of a boundary that separated the internal polymers from the environment - protobiont (also called protocells) - seperate external from internal contents - inside the protobiont contained information and had enzyme function; self relpicate - Cells may have evolved from coacervates & liposomes 4) RNA - Rna as the first macromolecule of protobionts - 3 functions – store information, self-replication, enzyme function - Advantages are information storage, metabolism, and cellular functions formation and accumulation of organic molecules polymerization of nucleic acids and proteins formation of protobionts synthesis of cell components by ribozymes synthesis of proteins by DNA, RNA & ribosome 9 replication of DNA Fossils - Sedimentary: rock that is implanted in water and soil and layers overtime / creates fossils - Igneous – crystalized rocks that decays/ allows individual to know the date of rock layers; contains radioactive isotopes which are unstable and decay overtime; measures the amount of given isotopes - Metamorphic – rocks made from pressure and heat that transform Factors that affect completeness of fossil record - Anatomy of organisms - Size - Number - Environment - Time Stromatolites ---> fossilized biofilms Hamelin Pool Australia – new cyanobacteria stromatolites Changes in living organisms are the result of 1) Genetic changes 2) Environmental changes - Climate - Atmosphere - Land - glaciations - Meteoric impacts Archaeans =Bacteria - The First cells were prokaryotic (lack nuclei) - Anaerobic (don't require oxygen) - Heterotrophs - Autotrophs (autotrophic cyanobacteria were preserved) Eukaryotes (cells with nuclei) - Multicellular - Multicellularity - Milestones in life - Bilateral symmetry - Both archaea and bacteria - Endosymbiotic relarionships Phanerozoic Eon = diversification of invertebrates and colonization of land plants and animals Cambrian - Warm and wet; cambrian explosion - Increase in diverse animal species Ordovician - Primitive land plants and arthropods - Climate change caused mass extinction Silurian - Coral reefs; terrestrial plants and animals - Earliest vascular plants Devonian (Age of fish) - Seed plants(gymnosperms) - Tetrapods --> amphibians emerge Carboniferous - Coal deposits - Amniotic eggs - Plants, trees, amphibians, and flying insect Permian - Pangaea (continental drift) - Mamal- like reptiles - Mass extinction Triassic (age of dinosaurs) - Reptiles - True mamals  - Land plants Cretaceous - Flowering plants and angiosperms - dinosaurs extinct but archosaurs survived - KT extincition tion Tertiary (Age of mammals) - Hominoids evolved - Angiosperms (flowering plants) Dominate Quaternary - Periodic ice ages - Homo sapiens evolve 130,000 years ago geological time scale ↓ delineated/separated by formation and extinctions of species (coincide with what?) Archaean = bacteria and Achaea Proterozoic = eukaryotes Phanerozoic: Paleozoic = land colonized Mesozoic = dinosaurs Cenozoic = hominoids Evolution - Heritable change of one or more characteristics of a population from one generation to another Microevolution - Changes in allele frequencies in a population over time Macroevolution - Formation of new species Theory - Hypothesis – a question that is testable - Theory- comprehensive explanation for a large body of information Darwin - Geology – important that the earth was older than 6,000 years - Economics – population is linked to resources - Darwin's trip consisted of collecting life and recording them - Made observations about animals and plants and was strucked by the distinctive traits of island species like birds; Galapagos Island had similar species of birds but different feeding strategies because of their beak - Specialization in feeding - Evolution was based on – variation within a given species – natural selection Evolutionary change (after Darwin) - Fossils – tetrapod – fossil records revealed adpative evolutionary changes in size - Biogeography – the study of geographical distibution of extinct and living species - Convergent evolution – two different species show similar chanracteristics becuase they have similar environments - Artificial selection- procedures to modify traits; choosing desirable phenotypes; Corns (Zea mays) dog breeds - Homology – anatomical homology – similarity due to descent from common ancestor – developmental homology –differ as adults' similarities during embryonic stages – Molecular homology – similarities in cells at the molecular level – DNA sequences of related species tend to be similar; example – p53 protein (prevents cancer) found in a diverse array of species