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Biology

Biology. Biology: Exploring Life Biology is the scientific study of life. Biological Hierarchy of Organization:. Life can exist here. http://www.ux1.eiu.edu/~cfruf/images/bio3002/els_le2.jpg. Hierarchy of Life; Organization levels.

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Biology

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  1. Biology Biology: Exploring Life Biology is the scientific study of life

  2. Biological Hierarchy of Organization: Life can exist here http://www.ux1.eiu.edu/~cfruf/images/bio3002/els_le2.jpg

  3. Hierarchy of Life; Organization levels Moleculesare atoms held together by chemical bonds (ex: DNA, protein) Organelles are membrane-bound structures with specific functions for & w/in some cells Cells are the smallest unit of life;separates the environment with a membrane Tissues are layers of cells to perform a specific function Organs are groups of tissues working together to perform a specific function

  4. Hierarchy of Life; Organization levels, cont’d Organ Systems are organs grouped together to perform a function Organism is a living thing within a population Population: the same species living within a specific area Community: many groups of different species within an ecosystem Ecosystem: contains biotic(living) factors &abiotic(nonliving) factors within a specified area/community Biosphere: all ecosystems of the Earth

  5. Hierarchy of Life; Organization levels, cont’d • From most specific to general: Atoms Molecules Organelles Cells Tissues Organs Organ Systems Organism Population Community Ecosystem Biosphere *Blue color denotes living/biotic

  6. Cycle of Nutrients and Energy: http://www.globalchange.umich.edu/globalchange1/current/lectures/kling/ecosystem/zebra2.gif

  7. Organism Interaction, Matter, and Energy • An Ecosystem contains 3 categories of organisms: • Producers (autotrophicorganisms likeplants, algae, and some bacteria): perform photosynthesis (absorb H2O, CO2 & sunlight & convert these to sugar and O2) • Consumers (heterotrophicorganisms like animals): organisms that eat plants and other animals. These take in O2 and release CO2, while releasing waste into the environment. • Decomposers (heterotrophic organisms like bacteria and fungi) that break down wastes and dead/decomposing organisms, while recycling matter into the environment (which the producers use).

  8. Organism Interaction, Matter, and Energy, Cont’d • Ecosystems have 2 major processes: Recycling chemical nutrients and energy flow. • Recycling chemical nutrients: O2, CO2, H2O, etc. go from the air and soil to producers to consumers to decomposers and then back to the air and soil. These are recycled! • Energy Flow:solar energy is absorbed by producers & converted to chemical energy thru photosynthesis. • Chemical energy is passed thru many organisms (consumers: primary to secondary, etc) and then finally to decomposers. • At every pass, some energy is LOST as heat. • Energy flows THROUGH the ecosystem (enters as light; exits as heat).

  9. Cells, the structural & functional unit of life • The cell is the basic unit of life, the lowest level of structure at which the properties of life emerge. These correlate structure = function! • The cell: • Regulates its internal environment (homeostasis) • Takes in & uses energy • Responds to its environment • Develops & maintains a complex organism • Reproduces (give rise to new cells)

  10. Cells, the structural & functional unit of life, Cont’d Characteristics of a Cell: • Enclosed in a membrane (which regulates the flow/regulation of materials in and out of the cell) • Contains DNA (genetic material), cytoplasm, ribosomes 2 types of cells: • Prokaryotic Cell (Kingdoms Archaebacteria and Eubacteria): bacteria; small and simple cells • Eukaryotic Cell (All other Kingdoms): plants, animals, protists, and fungi. • Have organelles (functional compartments with specific functions) • Have anucleus that contains DNA

  11. Prokaryote: Eukaryote: http://www.ichristianschool.com/biology/images/prokaryote.jpg http://faculty.uca.edu/~johnc/eukaryote.jpg

  12. Unity of Life • The continuity of life is based on ALL living things have DNA (genetic material). • Genes (inheritable material) are made up of DNA sequences • DNA is 2 chains coiled together to form adouble helix (structure) • Nucleotides= building blocks; these containnitrogenous bases attached: adenine (A), thymine (T), guanine (G), or cytosine (C). • All forms of life contain the same genetic code; the sequences (order) is different. This results in different genes. http://www.scq.ubc.ca/wp-content/dna.gif

  13. Unity of Life, Cont’d – CHARACTERISTICS OF LIFE: In addition to Genes, all organisms have: • Order (level of organization) • Metabolism (all chemical reactions) • Regulation (a.k.a. homeostasis, or control of the internal environment to sustain life) • Growth(increase in size) • Development (change in form) • Energy processing (ability to use & transform, or transduce, energy) • Response to Environment (both internal & external stimuli) • Reproduction (make more like themselves) • Evolutionary Adaptation (traits that are best suited to the environment that are passed on to the offspring; ie. camouflage, spots, etc)

  14. Diversity of Life – Classification of organisms • A species is the smallest category of organisms (most specific) • share the most common characteristics • can reproduce with each other. • Taxonomy is the branch of Bio which names & classifies organisms according to characteristics and similarities • molecular, genetic, biochemical, morphological, evolutionary phylogenies/histories, etc. This is completed from broadest category to most specific: Domain Kingdom Phylum Class Order Family Genus Species

  15. http://upload.wikimedia.org/wikipedia/commons/9/96/Scientific_classification.pnghttp://upload.wikimedia.org/wikipedia/commons/9/96/Scientific_classification.png http://www.lesley-smitheringale-fine-art.com/wp-content/uploads/2008/05/atlas-moth-scientific-classification.jpg

  16. There are 3 Domains: Domain Bacteria or Eubacteria, Domain Archaea, Domain Eukarya • Domain Bacteria or Eubacteria (have peptidoglycan in their cell walls) • Domain Archaea (live in extreme environments, like hot or salty places, or anaerobic environments) • BOTH Bacteria and Archaea are prokaryotic, are bacteria, are unicellular & microscopic, and are found in Kingdoms Archaebacteria and Eubacteria. • Domain Eukarya • Includeall eukaryotic organisms (have organelles & a nucleus). • Includeprotists (Kingdom Protista). These are uni or multicellular. Ex. Include algae and protozoans • Includeplants (Kingdom Plantae), which have a rigid cell wall and perform photosynthesis. • Include animals (Kingdom Animalia) which lack a cell wall and must consume food • Include fungi (Kingdom Fungi) which are yeast, mushrooms and molds that decompose dead organisms. • Protista, Plantae, and Fungi are generally separated by their modes of nutrition.

  17. Domain Arachaea: Image of Methanococcus jannaschii Domain Bacteria: Electron Micrograph of E. Coli http://www.biology.iupui.edu/biocourses/n100/images/dmethanopyrus.jpg http://www.foxnews.com/images/250204/0_61_bacteria_e_coli.jpg

  18. A Micrograph of Euglena (Protist): http://www.biologyreference.com/images/biol_04_img0381.jpg http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Evolution,%20Speciation,%20Taxonomy/specia12.gif Fungi: Death Cap, Death Angel Mushroom Plant: Palm Tree Animal: Bull Shark http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/bull-shark.jpg http://www.untiredwithloving.org/palm_tree_2.jpg http://www.gencat.cat/especial/bolets/img/toxics/farinera_borda1.gif

  19. Evolution Explains the Unity & Diversity of Life • Darwin wrote On the Origin of Species by Means of Natural Selectionwhich supported the idea of evolution= species alive today are descendants of ancestral species (a.k.a. ‘descent with modification’). • This means descent from a common ancestor. This supports the unity of life. • Darwin’s idea supported the diversity of life (modification as species diverged). http://www.goodschist.com/wp-content/gallery/charles-darwin/Darwin_age29.JPG

  20. Darwin recognized that variations existed within organisms. • These enhance their ability to survive AND reproduce(this is the essence of evolution by means of natural selection). • These successful adaptations are the result of evolution, the process of change over time which has transformed life on Earth.

  21. Evolution Explains the Unity & Diversity of Life, Cont’d • Darwin proposed that evolution occurred throughNatural Selection (NS): • Recognized (observed) that w/in a population,variations exist AND in many cases more organisms were produced than could survive (to produce their own offspring); this was an overproduction of offspring. • From these observations, he suggested that the individuals who were likely to survive AND reproduce were best suited to the environment; they inherited the best traits and would pass these traits on to their offspring. • Overtime, the best suited (or favorable) traits would accumulate within a population. This could eventually lead to a new species.

  22. Evolution Explains the Unity & Diversity of Life, Cont’d • The environment ‘selects’ for individuals w/certain traits meaning there is an unequal reproductive success. This is Natural Selection (NS). • The product of NS = evolutionary adaptation, or the accumulation of favorable traits in a population over time. • NS is an editing processthat works on heritable variations which are exposed to environmental factors that favor reproductive success. • Major alteration of a species could occur from many small changes w/in a population.Darwin proposed that a new species could arise due to these gradual changes over long periods of time.

  23. Scientific Method – terms that have different meanings in Science versus mainstream use: • Sciencemeans “to know.” “Science can neither prove nor disprove the existence of a God or supernatural power- for such questions are outside the bounds of science.” • A hypothesis is a possible (plausible) explanation based on observation (that can be tested). Mainstream use : an “educated guess” Theories in science: • A theoryis a hypothesis that has been tested repeatedly and is generally regarded as true. Examples: Theory of Evolution, Theory of Relativity, Atomic Theory, Cell Theory. Mainstream use: just an “idea”

  24. The Evolution Connection Evolution is the CORE theme in biology. • There are many differences (and similarities) in DNA among individuals, populations, and species; this reflects evolutionary change. • Through the Human Genome Project (HGP), scientists have been able to ID & construct the DNA base sequences of many species. • allowscomparative & functional genomics (the ability toidentify common genes, search for new medical treatments, and more using DNA technology). • DNA differences in humans is used in forensics: this is DNA fingerprinting or DNA profilingand is used to convict or exonerate, determine paternity, or identify remains.

  25. Evolutionary knowledge can help scientists in the understanding: • Vaccinations • HIV drugs • virus evolution • the development of antibiotic-resistant bacteria & pesticide-resistant crops • how to help endangered species

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