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Scientific Method

Scientific Method

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Scientific Method

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  1. Scientific Method Name the problem or question Form an educated guess (hypothesis) and make predictions Test your hypothesis by doing an experiment. Check and interpret (analyze) your results Report your results.

  2. Scientific Method • Constant – does not change in an experiment; stays the same through all trials • Control – “standard for comparison;” not tested • Independent variable – factor that is being tested; what the experiment (“I”) is testing • Dependent variable – result of the experiment; what happens because of the test

  3. Characteristics of Life • Made of cells • Reproduce • Grow and Develop • Use energy • Respond to stimuli • Maintain Homeostasis • Genetic Code

  4. Organic Molecules • Lipids: Fats, Oils, Steroids • Smallest unit - Fatty Acid & glycerol • Test: Brown Paper Bag Test • Proteins: Enzymes, Insulation, Help fight disease • Look for Nitrogen in the chemical formula or structure! • Smallest unit - Amino Acids & peptide bonds • Carbohydrates: Starches and Sugars (GLUCOSE) • Main Source of Energy • Smallest unit - monosaccaride • Test: Iodine • Nucleic Acids: DNA & RNA, Genetic / Hereditary Info. • Smallest unit - Nucleotide (sugar, phosphate, nitrogenous bases)

  5. Ecology Terms • Habitat- Place that an organism occupies for shelter. Includes abiotic and biotic factors. • Niche: Role organism plays within an ecosystem. Community Interactions • Competition: organism competes for resources • Predation: situation where one organism captures and feeds on another • Symbiosis: relationship where one organism lives in close association with another.

  6. Symbiotic Relationships • Mutualism- Both species benefit (Flower & Bee) • Commensalism- One species benefits and the other is neither hurt nor harmed. (Coral and Clown Fish) • Parasitism- One species benefits and the other is harmed. (Tick and Dog)

  7. Ecology Terms • Population= Same species, same area • Community= Different species, same area • Ecosystem= All Biotic and Abiotic parts • Producer, Plant, Autotroph= make own food, photosynthesis • Consumer, Heterotroph= consume other things to get energy. • Herbivore: only plants • Carnivore: only meat • Omnivore: plants and meat • Scavenger: eat dead material • Decomposer / Bacteria or fungi: Breakdown dead organic material and return nutrients to the soil

  8. Energy Pyramids • Shows the flow of energy within an ecosystem!! 10 energy units 10% C3 owl 100 energy units 10% HEAT C2 snake 1 000 energy units 10% C1 cricket 10 000 energy units Producers grass Greatest number of organisms, energy and biomass (amount of living substance) is found at bottom of pyramid!

  9. Behavior • Behavior: Way that an organism reacts to changes in its internal and external environment. • Stimulus: anything that makes an organism respond. EX: Light, Smell • Response: A single specific reaction to a stimulus. EX: Reflex • Innate Behaviors: Inherited behaviors

  10. Innate Behaviors • Migration: movement due to seasonal changes. • Hibernation: Response to cold to conserve energy • Estivation: Response to heat • Circadian Rhythm: 24-Hour Routine (day-night) • Territoriality: Animal defends territory / Reduces Conflict; uses resources efficiently; controls size of population  pheromones • Aggressive behavior: Intimidate another animal of same species to determine dominance hierarchy.

  11. Types of Learning • Habituation: Reduction in a previously displayed response  habit. Ex: Horses stop reacting to traffic! • Conditioning: learned behavior in response to a reward or punishment  training. Ex: Pavlov's Dog • Trial and Error: learning which involves practice. • Insight Learning: Learning from experience  problem solving. • Imprinting: Animal forms a social attachment to another object at a specific time. Ducks/Birds!!

  12. Cell Theory All living things are composed of cells. Cells are the basic unit of life. New cells come from old cells.

  13. Levels of Cellar Organization Cells Tissues Organs Organ System • Cells- basic unit of living things • Tissues- a group of similar cells that perform a particular function. • Organs- groups of tissues that work together to perform a task. • Organ System- a group of organs that work together to perform a specific function.

  14. Prokaryotes Smaller and Simpler No Nucleus / Nucleoid Bacteria Eukaryotes Larger and Complex Contain more Organelles Nucleus Plants, Animals, Fungi, and Protists Two types of cells

  15. Animal cell do not have a cell wall or chloroplast. Plant cells have a cell wall and chloroplast Plant and Animal Cells

  16. Cell Organelles • Nucleus: Brain of cell (DNA) • Cytoplasm: Houses all the cells organelles • Ribosome: Protein Synthesis • Vacuole: Storage • Chloroplast: Site for Photosynthesis • Mitochondria: Site for aerobic respiration (ATP) • Cell Wall: Extra support & protection, cellulose. • Cell Membrane: allows some things in and others out.

  17. Cell Membrane/Plasma Membrane • Phospholipid bilayer (two layers of phospholipids) • circular phosphates - hydrophillic (like water) • fatty acid tails (lipids) - hydrophobic (don’t like water) • Transport proteins allow movement of materials in and out by active and passive transport. • Cholesterol – keeps lipids from sticking

  18. Homeostasis • Homeostasis- balance between internal and external environment of cell. Factors Affecting Homeostasis • Temperature • pH Level • Salt Concentrations

  19. Passive Does not require ATP Move from high concentration to low concentration. Osmosis (WATER) Diffusion (MOLECULES) Active Requires ATP Move from low concentration to high concentration. Facilitated Diffusion Types of Transport

  20. Cellular Movement (OSMOSIS) • WATER FOLLOWS THE SMALLER #!! • DISTILLED WATER IS ALWAYS 100%! Steps to solve problems • If problem only contains water just follow the rule that water follows the smaller #! • If solute is given subtract the number from 100 to get the amount of water. • Once you have the amount of water for the inside and out, follow step one.

  21. What is an Enzyme? • Proteins that catalyze (speed) chemical reactions within a cell. • LOCK AND KEY (Specific for substrate) Factors affecting enzyme activity • pH • Temperature

  22. Enzyme Activity

  23. Cell Communication Cells communicate to maintain Homeostasis!! • Hormonal Communication - chemical message that travels through the bloodstream to a target cell or target organ. • Neuron Communication - method that allows organisms to detect and respond to stimuli.

  24. PARTS OF A NEURON • Axon - sends message • Dendrite- receives message

  25. Aerobic Requires Oxygen Mitochondria Provides Cell with ATP Anaerobic No Oxygen Required Fermentation Bacteria 2 Types of Fermentation Alcoholic: Alcohol / Yeast Lactic acid: Muscle Soreness Respiration


  27. Respiration in Humans = diffusion in Lungs Oxygen goes into the lung Carbon Dioxide leaves the lung O2 CO2


  29. DNA • Deoxyribonucleic Acid • Double Helical Structure (Watson and Crick) • Deoxyribose Sugar • Determine Traits • Found in Nucleus • Hydrogen Bond holds bases together. • Covalent Bonds hold phosphates and sugars. • Bases: GCAT • G=C • A=T

  30. Hydrogen Bond Holds bases! Covalent Bond holds sugar and phosphate!

  31. DNA Replication • USE BASES GCAT • TAKES PLACE IN THE NUCLEUS Steps • DNA polymerase separates the original strand of DNA. (unzips) • Replication begins on both strands of DNA following the rules of base pairing.

  32. RNA • RNA is Ribonucleic Acid • Ribose Sugar • Single Stranded • Bases: GCAU • G=C • A=U • Protein Synthesis

  33. Three types of RNA

  34. Protein Synthesis • Process whereby DNA encodes for the production of amino acids and proteins. • Process is divided into two parts: • Transcription: Nucleus • Translation: Ribosome • 20 Amino Acids held by peptide bonds. • 64 combinations for Codons • Codons: 3 letter base sequence that codes for one amino acid. EX: AUG

  35. TRANSCRIPTION • Nucleus • Base U is used instead of T. • mRNA is created. TRANSLATION • Ribosome • Amino acids are brought to mRNA strand by tRNA. • Amino acids are held together by peptide bondsprotein.

  36. Mitosis • Results in Diploid (2n) cells = 46 chromosomes. • daughter cell is identical to parent cell • Interphase is the longest of the phase  DNA replication and other preparation for cell division. • Body Cells (SOMATIC) 4 Stages: PMAT • Prophase • Metaphase • Anaphase • Telophase • Cytokinesis

  37. Meiosis • Sperm in Males • Ova or Egg in Females • 2 Cell Divisions • Haploid Cells (n=23) • Produces 4 total cells • 4 sperm • 1 egg & 3 smaller cells

  38. Gene Mutations • Point Mutations- mutation that affects a single nucleotide only at a specific point. • Frame shift Mutations- mutation that shifts the reading frame of the genetic message by inserting or deleting a nucleotide.

  39. Gene Chromosome Model Body  Cells  Chromosomes  Genes DNA • Genes Provide Organisms with: • Looks • Some illnesses • Body Structure

  40. What is Genetic Engineering? • Method of inserting foreign DNA into a host organism of the same or different species!! • Known as Recombinant DNA Technology!! • Recombinant DNA is foreign DNA!

  41. Genetic Engineering • Process of making changes in the DNA code of living organisms. • Gel Electrophoresis- a procedure used to separate and DNA fragments into bands. • Cloning- copying an organisms DNA to make an exact copy of the same organism.

  42. DNA Fingerprinting  Identifies crime suspects Identifies paternity 

  43. Mendel’s Work • Study of Heredity (Gregor Mendel= Pea Plants) • Genes – chemical factors that determine traits • Alleles – different forms of genes • Traits – a specific characteristic, such as color or plant height, that varies form one individual to another • Dominant traits always show up in an offspring (capital letter) • Recessive traits are masked by a dominant gene (lower case letter) • Hybrids – The offspring of crosses between parents with different traits

  44. Genetics • Principle of Dominance: some alleles are dominant and others are recessive. • Principle of Independent of Assortment- genes for different traits can segregate independently during the formation of gametes. • Incomplete dominance- situation in which one allele is not completely dominant over another. WHITE and RED = PINK • Codominance- situation in which both alleles of a gene contribute to the phenotype of the organism. BLACK and BLUE= BLACK & BLUE • Multiple Alleles = having three or more traits for the same gene.

  45. Multiple Alleles / Blood Type • NOTE: O blood type is recessive. • O= little i • Blood Types: A, B, AB, & O • OO = blood type OAO = blood type ABO = blood type BAB = blood type ABAA = blood type ABB = blood type B

  46. Genetics • Homozygous (PURE)= TT or tt (SAME) • Heterozygous (HYBRID)= Tt (Different) • Phenotype= Physical characteristics • Genotype= genetic makeup using alleles (Letters) • Sex-linked Traits= genes found only on the X chromosome and not on the Y chromosome. • Males= XY • Females= XX

  47. Monohybrid Cross Heterozygous tall parent T t T t T TT Tt Tt tt T t Heterozygous tall parent

  48. Test Cross T T • Always use homozygous recessive • If all offspring have the dominant trait then the genotype is probably pure (TT x tt) • If some of the offspring show the recessive trait, then the genotype is heterozygous.(Tt x tt) Tt Tt t t Tt Tt T t t Tt tt t Tt tt