B1 - Cell BIology

• What are the two main types of cells in living organisms?

  Prokaryotic and eukaryotic
• What are the components of eukaryotic cells?

  • Cell membrane
  • Cytoplasm
  • Nucleus containing DNA
• What are the components of prokaryotic cells?

  Cell wall, cell membrane, cytoplasm, single circular strand of DNA, and plasmids
• What is the function of organelles in a cell?

  They have different functions within the cell
• How do we use orders of magnitude to compare sizes?

  By expressing how many times larger or smaller one object is than another
• What does a prefix in measurement indicate?

  It shows the multiple of the unit being used
• What are the prefixes used in measurements and their values?

  • Centi: 0.01
  • Milli: 0.001
  • Micro: 0.000001
  • Nano: 0.000000001
• What is the role of the nucleus in a cell?

  It contains DNA coding for proteins needed to build new cells
• What is the function of cytoplasm?

  It is the liquid substance where chemical reactions occur and contains enzymes
• Where do aerobic respiration reactions occur in a cell?

  In the mitochondria
• What is the function of the cell membrane?

  It controls what enters and leaves the cell
• What is the role of ribosomes in a cell?

  They are where protein synthesis occurs
• What is the function of chloroplasts in plant cells?

  They are where photosynthesis takes place
• What is contained in the permanent vacuole of a plant cell?

  Cell sap
• What is the function of the cell wall in plant cells?

  It provides strength to the cell
• How can you calculate the size or area of sub-cellular structures?

  By finding a shape that resembles it and applying the appropriate area formula
• How do bacterial cells differ from eukaryotic cells?

  Bacterial cells do not have a nucleus and have different organelles
• What is cell differentiation?

  • The process by which cells gain new sub-cellular structures
  • Suits them to their specific roles
  • Can occur early in development or throughout life (in stem cells)
• What is the function of sperm cells?

  To carry the male's DNA to the egg cell for reproduction
• How are nerve cells specialized for their function?

  They have a long axon and many dendrites for transmitting signals quickly
• What is the role of mitochondria in muscle cells?

  They provide energy for contraction
• What is the function of root hair cells?

  To take up water and mineral ions from the soil
• How do xylem cells function in plants?

  They transport water and mineral ions from roots to shoots
• What is the role of phloem cells?

  To carry the products of photosynthesis to all parts of the plant
• What happens during differentiation of stem cells?

  Some genes are switched on or off to produce different proteins
• How do most specialized cells in animals reproduce?

  By undergoing mitosis to produce identical cells
• How do plants retain the ability to differentiate?

  Many types of cells can differentiate throughout their life
• Who first observed cells and when?

  Robert Hooke in 1665
• What is the maximum magnification of a light microscope?

  x2000
• What is the resolving power of a light microscope?

  200 nm
• What is the difference between scanning and transmission electron microscopes?

  SEMs create 3D images, while TEMs create 2D images
• What is the maximum magnification of an electron microscope?

  x2,000,000
• What is the formula for calculating the size of an object?

  Size of image / magnification = size of object
• What is standard form used for in microscopy?

  To handle very large or small numbers
• What is the culture medium for growing microorganisms?

  A mixture containing carbohydrates, minerals, proteins, and vitamins
• What is the purpose of sterilizing Petri dishes and culture media?

  To prevent contamination by unwanted microorganisms
• How do bacteria multiply in a suitable environment?

  By binary fission, splitting into two
• What is the purpose of using antibiotics in bacterial growth experiments?

  To test their effects on bacterial growth
• What is the formula for calculating the number of bacteria at the end of a growth period?

  Bacteria at beginning x 2$^{\text{number of divisions}}$ = bacteria at end
• What is the role of the inhibition zone in antibiotic testing?

  It indicates how effective the antibiotic is at killing bacteria