BIO 110 Lecture (Chap 1)
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Transcript of BIO 110 Lecture (Chap 1)
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BIOLOGY 110: GENERAL BIOLOGY Lesson 1
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Specific ObjectivesUnderstand the tenants of Biology as a field of scienceKnow the properties of living and non-living thingsUnderstand that there is diversity in living organismsUnderstand the concept of a species and hierarchical classification Describe the highest levels of classification, including the 6 kingdoms and 3 domainsKnow the basic theories of evolution, including Darwins natural selection
Understand the process of scientific investigation and some basic history of scientific thought
Understand and apply scientific methods and study design in research
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What is Science?Science (Latin scientia: meaning "knowledge" or "knowing)the effort to discover, and increase human understanding of how the physical world works.
systematic observation of natural events and conditions in order to discover facts about them and to formulate laws and principles based on these facts.
the organized body of knowledge derived from systematic observations and that can be verified or tested by further investigation.
Many branches or general bodies of knowledge
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What is BiologyGreek: bio= life, logy= study of
The scientific study of life and of living organisms.
Some branches; botany, zoology, and ecology etc.
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Unifying Themes in BiologyOVERVIEWInformation transfer:~ hereditary information is passed from on generation to the next, and it controls the development and life of each cell
Energy for life~ energy from the sun is converted to chemical energy which is used to drive chemical processes within cells
Evolution~ biologys core theme; differential reproductive success ; POPULATIONS CHANGE OVER TIME
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Characteristics of Life
Organisms are organized Grow and developRespond to stimuliCapture and use energy (metabolism)Regulate their internal environmentReproduceEvolve and become adapted
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Characteristics of LifeOrganisms are organized Composed of cellsCell theory: new cells originate only from pre-existing cellsProkaryotic vs. eukaryotic cellsSingle celled vs. multicellular organisms
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Prokaryotes and EukaryotesMonerans (bacteria) have prokaryotic cells. All are unicellular organisms.Protists, Fungi, Plants and Animals have eukaryotic cells. These may be unicellular or multicellular
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Hierarchy of Organization AtomMoleculeCells (single cell organisms)TissuesOrgansOrgan SystemsMulticellular OrganismsLiving Things are ORGANIZED
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Characteristics of Life (continued)Organisms grow and developGrowth- an increase in cell size, cell number or both.
Development- All the changes that take happen during an organisms lifespan
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Characteristics of Life contd3. Organisms respond to stimuli
Living things react to stimuli (physical and chemical changes in their internal and external environments). Responding typically involves some form of movement
Movement may be created by Cilia & Flagella; Bones and Muscles; Expansion of certain cells to orient leaves to sunlight
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Characteristics of Life (continued)4. Organisms capture and use energy
Metabolism- the sum of all the chemical reactions within an organism- Energy producing pathways (eg. photosynthesis)- Energy releasing pathways (eg. cellular respiration)
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Characteristics of Life (continued) 5. Regulate their internal environment via Homeostasis- maintaining a constant internal environment
Regulated by feedback systems- Negative vs. positive feedback systems
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Feedback Regulation: Negativecounteract the stimulus that is disrupting homeostasis
Typically accumulation of an end product of a process slows that process
Example: sugar breakdown generates ATP; excess ATP inhibits an enzyme near the beginning of the pathway
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Feedback Regulation: PositiveWhen the original stimulus enhances the response
An end product speeds up its production
Examples: blood clotting in response to injury; uterine contractions
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Organisms reproduceAsexual reproduction (One gives rise to two or more) Sexual reproduction: (gametes fuse to form a zygote)Characteristics of Life (continued)
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Characteristics of Life (continued)Populations evolve and adaptEvolution- changes in population over time
Adaptations- inherited characteristics that increases an organisms chance of survive in a particular environment
Adaptations may be structural, physiological, and/or behavioural
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Upper Levels of the HierarchyPopulationCommunityEcosystemBiosphere
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Information Transfer Information transfer occurs Within organismsCell to cell chemical signalsNerve cells; Hormones
Between organismsBehaviour; Chemical communication (pheromones)
Among generations
Information encoding the instructions for the sustenance of life is transferred from one generation to the nextDNA is the hereditary molecule
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Classification of organisms by Evolutionary RelationshipMost biologists now recognize six (6) kingdoms
Early biologists only recognized the plant and animal kingdoms
Some biologists split the bacteria into 2 separate kingdomsKingdom Archaebacteria (unique group of organisms recently have split off from the bacterial kingdom)
Kingdom Eubacteria (bacteria)
Kingdom Protista (protozoans and algae, molds)
Kingdom Fungi (mushrooms, molds, and yeasts)
The animals are in kingdom Animalia
Plants belong to kingdom Plantae
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Classification of organisms by Evolutionary RelationshipThe diversity of the world today is extremely vast
Biologists use a binomial system for classifying organisms
Developed by Carolus Linnaeus
Binomial nomenclature describes the genus and species of the organism (genus + specific epithet
Taxonomy (the science of classification) is hierarchical a. Kingdoms- phyla- classes- orders- families- genera- species
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Classification of organisms by Evolutionary Relationship3 Domains have been recently recognized into which the 6 kingdoms have been placedArchaeaBacteriaEukarya
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Classification of organisms by Evolutionary Relationship
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Energy & LifeLife depends on a continuous input of energy from the sun
Energy flows through individual cells and organisms
Cellular respiration produces energy (ATP) for most cells
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Energy & LifeEnergy flows through ecosystems
1. Energy flows from producers to consumers to decomposers
2. Producers manufacture their own food a. Producers (autotrophs) are typically photosynthetic
3. Consumers (heterotrophs) obtain energy by eating producers
4. Decomposers obtain energy from wastes and dead organisms (eg. various bacteria and fungi)
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Energy Flow through Ecosystem
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The Process of Science Biology is studied using the scientific method
Like other sciences it is based on systematic thought processes including both deductive and inductive reasoning
Deductive reasoning works from the more general to the more specific. ("top-down" approach); Theory- hypothesis- observation- confirmation
Inductive reasoning works the other way, moving from specific observations to broader generalizations and theories. ("bottom up" approach); Observation- pattern- tentative-hypothesis- theory
Scientists make careful observations and recognize problems
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The Process of Science
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The Process of Science A hypothesis is a proposed explanation which is testableA prediction is a logical consequence of a hypothesisPredictions can be tested by experimentationScientific experiments include experimental and control groupsScientists draw conclusions from the results of experimentsA well-supported hypothesis may lead to a theoryA theory which is nearly universally accepted is a principle Laws are principles of the greatest importanceScience has ethical dimensions
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