Biology

• Biology


  The study of living organisms
• What do biologists do?


  • Study the diversity of life
  • Research disease
  • Improve agriculture
  • Display organization
  • Develop technologies
  • Preserve the environment
• Characteristics of a living organism


  • Multicellular
  • Organize cells into tissues, organs, and systems
  • Response to stimuli
  • Reproduction
  • Maintain homeostasis
  • Adaptation
• The scientific method


  1. Ask a question

  2. Draw a hypothesis

  3. Experiment/investigation

  4. Collect data

  5. Form a conclusion
• Variables


  • Independent
  • Dependent
• Data


  • Quantitative
  • Qualitative
• Experimental group


  Group exposed to changes to test the hypothesis
• Control group


  For comparison
• Conclusion


  Assumption based on past experience
• Units of biology


  • Meters
  • Kilograms
  • Liters
  • Seconds
• Classification


  The grouping of organisms
• Binomial nomenclature


  The biological system of naming organisms, composed of genus and species
• Rules for binomial nomenclature


  • Only the first letter of the genus is capitalized
  • Underlined or in italics
• Levels of classification


  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• The word 'division' is used instead of 'phylum' when classifying plants and bacteria
• Taxonomy


  Placing living organisms into groups
• Classification was based on morphology (shape and behaviour)
• Domains


  • Archaea
  • Bacteria
  • Eukarya
• Prokaryotes


  Microscopic, single-celled organisms that contain DNA and lack a nucleus membrane and membrane-bound organelles
• Prokaryote structure


  • Chromosomes
  • Capsule
  • Pili
  • Flagella
  • Cell walls
• Pili


  Attach to surface
• Capsule


  Prevent the cell from dying out
• Halophilic achae


  Live in very salty environments
• Thermoacidophiles


  Thrive in temperatures above 80 and a PH number between 1 and 2
• Methanogens


  Use carbon dioxide to breathe and produce methane gas, found in sewage treatment, plants and swamps
• Prokaryotic cell structures


  • Ribosomes
  • Pili
  • Chromosome
  • Capsule
  • Cell wall
  • Plasma membrane
  • Plasmid
  • Flagella
• Gram-positive bacteria


  Appear dark purple when stained, have a thick peptidoglycan cell wall
• Gram-negative bacteria


  Appear pink, have a thick outer layer of lipids and a few peptides and glycans
• Prokaryotic proliferation


  1. Binary fission

  2. Conjugation
• Benefits of bacteria


  • Nitrogen fixation
  • Normal flora in digestive tract
  • Used in food production
• Bacterial diseases


  • Respiratory diseases
  • Skin diseases
• Virus


  A non-living strand of genetic material within a protein coat
• Virus forms


  • Adenovirus
  • Influenza virus
  • Bacteriophage
  • Tobacco mosaic virus
• Virus diseases


  • Sexually transmitted diseases
  • Respiratory diseases
  • Childhood diseases
  • Nervous system diseases
  • Other diseases
• Retrovirus


  Genetic material has RNA instead of DNA, best known is HIV-AIDS
• Prions


  Protein that can cause infection or disease, e.g. mad cow disease
• Protozoa


  Single-celled eukaryotes that commonly show characteristics associated with animals, like mobility and heterotrophy
• Protozoan types by locomotion


  • Amoeba
  • Flagellates
  • Apicomplexa
  • Ciliates
• Foraminiferans and Radiolarians


  Protists whose fossilized remains are used by geologists
• Plant-like protists (Algae)


  • Diatoms
  • Euglenoids
  • Green Algae
  • Red Algae