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  1. 1. 1 Bio I Biology: Biolife LogyGr.“Logos” = study of Characteristics of life 1. Cellular - Made up of cells 2. Able to Reproduce - The ability to perpetuate 3. Genetic code DNA :Adenine, Guanine, Cytosine, Thymine RNA: Adenine, Guanine, Cytosine, Uracil deoxyribonucleic acid ribonucleic acid DNA – carrier RNA – messenger DNA is self-replicating which is efficient for survival Nucleic acids ~ nucleotides 1. 5C simple sugar 2. N-bases 3. Phosphate PO4  DNA and RNA Central / Molecular Dogma 4.Grow and Develop Grow – increase size and/or number of cells Develop –changes from early stages to the mature stages 5. Metabolism – sum total of all chemical reactions 6. Exhibit to Irritability – respond to environment 7. Undergo homeostasis – can maintain internal balance 8. Adapt and evolve – suited to live in its particular environment Themes that unify Biology 1. Cell Every organism’s basic units of structure and function Two main types: Prokaryotic ( bacteria, archea) Eukaryotic(Protists, plants, fungi, animals) 2. Heritable information The continuity of life depends on the inheritance of biological information in the form of DNA molecules Genetic information is encoded in the nucleotide sequences of DNA 3. Emergent properties The world has a hierarchical organization Emergent properties – the result of interactions among components at the lower level.
  2. 2. 2 4. Regulation Feed back mechanisms regulate biological systems. Unity and diversity Biologists divided life into 3 domains: › Bacteria , Archea , Eukarya Unity  universal genetic code The more related, the more characteristics they share Evolution Darwinian theory of natural selection Adaptation of populations are through differential reproductive success of varying individuals Scientific inquiry The process of science includes observation- based discovery and the testing of explanations through hypothesis based inquiry. Levels of organization 1. Atom 2. Molecule 3. Tissue 4. Organ 5. Organ system 6. Organism 7. Population 8. Community 9. Ecosystems 10. Biome 11. Biosphere Ecology - Study of interaction among organisms in their environment Relationships Biotic – biotic Abiotic – abiotic Abiotic - biotic Biosphere Portions of the planet in which life exists  Atmosphere  Hydrosphere  Lithosphere  Self-contained  Patchy Biomes Group of ecosystems that have the same climate and similar dominant communities Habitat – area where organisms live Niche – role in the area Ecological Niche Each organism has a specific role that contributes to the ecosystem
  3. 3. 3 Ecological succession  the observed process of change in the species structure of an ecological community over time.  The most efficient and most adapted organisms become the most adundant species  Occurs when there are drastic and sudden changes in the environment Pioneer community- the organisms present that are most suited for this environment  Pioneer species Climax community – organisms that are most suited for the present environment after the change  Dominant species Competitive exclusion principle Fundamental rule in ecology stating that no two organisms can occupy the exact niche for an indefinite time Perinial – long life Annual – yearly Biannual – every two years Flow of energy This the factor that controls what kind of organisms live in an ecosystem Determines the max number of organisms in an ecosystem Producers – produces energy storing molecules Consumers – consumes plants and obtains their energy Decomposers – returns organic molecules to the ground Scavengers – consumes carcasses Primary energy source Photosynthetic organisms:plants, algae, bacteria Primary productivity – the rate at which organic material is produced. Primary productivity determines the amount of energy available in the ecosystem Trophic levels Feeding positions in a food chain These are represented in: food chains, food webs, and ecological pyramids. Food chains – sequence of food and energy transfer. Producer consumer  decomposer Food webs – food chains that intersect and link to each other Ecological pyramids: Number pyramid Biomass pyramid Energy pyramid
  4. 4. 4 Population dynamics Referred to as how a number of individuals change over time Important for the conservation of endangered species and management of life Exponential growth is unrealistic Everything has a limit Carrying capacity- population size that the environment can sustain for a long period of time. Important characteristics of a population 1. Geographic distribution / range 2. Population density 3. Population dispersion 4. Uniformity 5. Random clustering Factors that limit population size 1. Natality 2. Mortality 3. Number of individuals entering or leaving an ecosystem Limiting factors Density-dependent › Competition › Predation › Parasitism › Disease Density-independent › Unusual weather › Natural disasters › Season cycles › Human activities Abiotic and biotic factors that limit aquatic biomes  Water chemistry  Temperature  Depth of water o Light penetration o Turbidity o O2 content o Wind action, water current, microbial action  Water pressure  Salinity of aquatic biomes  Biological Oxygen Demand  Eutrophication  Turnover / upwelling  Early theories on Evolution Historical development Carolus Linnaeus– Nested Hierarchies, Order of Nature. Classified humans among primates Plato – idealism / essentialism. Its attributes are essentially determined and made. Aristotle – ScalaNaturae: Organisms arrange in increasing complexity Judeo Christian culture – Creationism “admajoremdeigloriam”natural theology
  5. 5. 5 SystemaNaturae - KPCOFGS Binomial system of Nomenclature Genusspecies Thomas Malthus – ecology of human popuations Jean Baptiste Lamarck – Naturalist  PhilosophieZoologique: Desire to change, use and disuse, passing of acquired traits Georges Cuvier – catastrophism, extinctions Charles Lyell – uniformitarianism James hutton – Graudualism Profound change is the cumulative product of slow but continuous process George Mendell – father of modern genetics  discrete genes are inherited Charles Darwin – naturalist  Theory of natural selection Alfred Russel Wallace – theory of natural selection Modern Theories Francis Crick & James Watson – DNA Understood mutations arrive to evolution Rosalind Frank – x-ray crytallography Structure is correlated with function  Further explanation Malthusian Dilemma Thomas Malthus believed that the human population would eventually grow larger than the ability of the environment to sustain it. Natural vs. Artificial Selection Natural – longer and random Artificial – faster and has goals Types of biomes Desert - Little water, Extreme temperature changes, Hot and Dry, Difficult to adapt Includes: Hot and Dry, Semiarid, Coastal, and Cold deserts Forests - Dominated by trees and plants, Diverse in terms of kinds of species Includes: Tropical, Decidiuous, and Taiga Freshwater - Has water that has a salt level < 1%, A lot of plants and animals, Source of drinking water Includes: Ponds, lakes, Streams, Rivers and Wetlands Grassland - Filled with grasses, Length of grasses depend on amount of rainfall Marine- covers more of the Earth’s surface than any other – about 70%, provides most of the rainwater Tundra - Cold climate, Remains wet because of the cold temp that delays evaporation Finnish: Tunturi- treeless hill