BIOL202 Lesson 4

• Observational study


  Establishes possible correlation, but does not establish causation
• Cohort study


  Observe 2+ groups of people over time to note disease frequency difference between groups
• Case-control study

  Observe people with or without disease and the occurrence of factors associated with disease
• Retrospective study

  
  

  Based on recall; may not be reliable
• Perspective

  
  

  Observe people before disease appears
• Blind study


  Subjects don't know which treatment (if any) they are Receiving
• Double-blind


  Neither subjects nor the experimenter knows which treatment the subject is receiving
• What is the cell theory?


  All organisms are composed of cells; All cells come from preexisting cells
• What is a prokaryote?


  No nucleus, no membrane-bound organelles
• What are eukaryotes?


  Larger than prokaryotic cell, it contains a nucleus and membrane-bound organelles
• Cell structures common to prokaryotes + eukaryotes


  • Plasma membrane: separates cell contents from the environment; made of phospholipid bilayer
  • Cytoplasm thick jelly-like fluid fills inside of the cell
  • DNA: a molecule that stores genetic information; stored in the cytoplasm for prokaryotes in the nucleus for eukaryotes
  • Ribosomes: granular structure found in cytoplasm; they synthesize proteins
• What is membrane invagination?


  eukaryotes derived from prokaryotes; plasma membrane folded in on itself which formed organelles
• What is endosymbiosis?


  Derived from symbiosis (two organisms co-exist with each other); mitochondrion and chloroplast are derived from bacteria-like organisms that were engulfed by the ancestors of eukaryotes
• What are the basic structures in prokaryotes?


  Cell wall: rigid protective layer

  Capsule: facultative, gelatinous layer outside of cell wall

  Pili: hair-like structures that attaches to other cells

  Flagellum: whip-like projection that propels cell
• What are the two structures derives from endosymbiosis?

  Mitochondrion and Chloroplast
• What are the 5 structures derived from membrane invagination?

  Nucleus, endoplasmic reticulum (ER), Golgi apparatus, lysosome, and vacuoles/vesicles