Bio Exam

• Biology


  The study of life and living organisms
• Living organisms


  Those that are made up of cells
• The word biology only came after the invention of the microscope when cells become visible
• The Cell Theory


  • The fundamental unit of life is the cell
  • All living things are made up of cells
  • All cells come from preexisting cells (they cannot form from non living things)
• Virus


  Non living
• Cell/ Plasma Membrane


  • Semi Permeable outer covering of the cell that contains the cytoplasm within it
  • Controls what goes in and out of the cell
  • Made up of a phospholipid bilayer ( each phospholipid has a hydrophilic phosphate head and two hydrophobic fatty acid tails.)
• Cytoplasm


  • Refers to the entire inner space of the cell
  • The actual fluid is called cytosol
• Cytoskeleton


  Inside the cell is a network of proteins that hold the cell together and maintains its structure
• Ribosomes


  • Synthesize proteins reading the genetic code
  • Some people argue that ribosomes is the fundamental sign of a truly living organism
• Nucleus


  Stores and protects the genetic material (DNA)
• Nucleolus


  • Makes ribosomes
  • Inside of nucleus
• Vesicles/ Vacuoles


  • Transport and storage compartments
  • Made up of the same material as the cell membrane so that they can easily fuse with it
  • Vesicles: Transport
  • Vacuoles: storage
• Lysosome


  • A special kind of vacuole that is full of enzymes to break down matter that the cell ingests
  • Enzymes are biological catalysts proteins, that "do things" in the cell
• Golgi body


  • The packaging and "dispatch" center for many vacuoles
  • Usually packages vesicles to transport proteins out of cell
• Exocytosis


  When a vesicle fuses with the membrane to excrete materials out of the cell
• Endocytosis


  Ingesting materials into the cell
• Phagocytosis


  When a cell eats another cell (or something else very large)
• When it's dark


  Our bodies produce melanin which is what helps us go to sleep
• Smooth ER


  • Like the golgi body, it packages vesicles for transport
  • Specializes in making, modifying and packaging lipid (fat) molecules
• Rough ER


  • "Rough" because it is studded with ribosomes
  • The proteins made by these ribosomes are modified by the ER and packaged into vesicles
• Mitochondria


  • The "powerhouse" of the cell
  • Make up the bulk of the cells energy (in the forms of the molecule ATP)
  • They have their own membrane, DNA and metabolism
  • They divide independently
  • They are like separate living organism within our cell - an example of endosymbiosis
• Endosymbiosis


  A living organism that lives inside of another living organism
• Symbiosis


  Two living things that depend on each other
• Animal cells have 3 major forms of locomotion


  • Flagella - propeller like motion, tail like
  • Cilia - back and forth motion, hair like
  • Pseudopodia - feet movements
• Centrosome


  • Flagella and cilia are made with the assistance of the centrosome
  • Its main role is to produce spindle fibers during mitosis
  • Helps maintain the cytoskeleton
  • Composed of two centrioles
  • Only in animal cells (not plants)
• Plant cells have


  • A tough outer cell wall (makes celery crunchy)
  • A large water vacuole
  • Chloroplasts for photosynthesis
  • Mitochondria
  • Do not have flagella, cillia, pseudopodia since they cannot move
• Cells are just 20 microns in size, but they are incredibly complex, scientists still have no clue how the cell "knows" to do all that it does
• Cells combine to form

  • Tissues
  • Tissues combine to form organs
  • Organs together make an organ system
  • All together we have an organism
• 4 types of tissue

  • Connective
  • Epithelial
  • Muscle
  • Nervous
• Organ


  • A self contained part of the body
  • Usually has two or more tissue types working together
• Organ system


  A group of organs that work together to perform a set of functions
• Smooth muscle


  • Muscle you cannot control
  • Ex. heart
• Amoeba cell


  • Single celled organism
  • Don't mate - use morphology
  • Ex. Their is a brain eating amoeba that can be found in water, people die from it
• Organelle


  • Functions
  • Present in?
• Organelles present in


  • Animals
  • Plants
• Biodiversity is "the variety and number of life forms on earth"
• Scientists have identified nearly 2 million species and some believe that there could be as many as 10 million
• Species


  A group of organism that are able to breed freely amongst themselves under natural conditions, and produce fertile offspring
• Hybrids


  Mixed species
• Hybridization is far more common in plants