Cell Biology

• What do animal cells contain?

  Nucleus, cell membrane, cytoplasm, ribosomes, mitochondria
• What is the function of the nucleus in animal cells?

  Stores genetic information
• What is the role of mitochondria in animal cells?

  Release energy in respiration
• What type of cells are animal and plant cells classified as?

  Eukaryotic cells
• What additional structures do plant cells have compared to animal cells?

  Permanent vacuole, chloroplasts, cell wall
• What is the function of chloroplasts in plant cells?

  Where photosynthesis happens
• What is the composition of the cell wall in plant cells?

  Made of cellulose
• What type of cells are bacteria classified as?

  Prokaryotic cells
• What is the structure of bacterial DNA?

  Single DNA loop or plasmids
• What do bacteria lack compared to eukaryotic cells?

  No nucleus
• Why don't bacteria contain mitochondria?

  Too large to fit in the cell
• Compare bacteria and eukaryotic cells on the presence of a nucleus.

  • Bacteria: No nucleus (loop DNA/plasmids)
  • Eukaryotic cells: Have a nucleus
• Compare the size of bacteria to eukaryotic cells.

  • Bacteria: Smaller than eukaryotic cells
  • Eukaryotic cells: Larger than bacteria
• What is the function of specialized cells?

  Adapted structure for specific functions
• What is the unit conversion from mm to µm?

  1 mm = 1000 µm
• What is the formula for magnification?

  Magnification = Image/Object
• What is an order of magnitude?

  Approximate comparison between numbers
• What does resolution refer to in microscopy?

  Ability to distinguish points close together
• What type of microscope is commonly used in schools?

  Light microscope
• What can light microscopes see?

  Larger cell parts like the nucleus
• Why are electron microscopes better than light microscopes?

  Higher resolution and magnification
• What are the steps in the required practical for observing cells under a microscope?

  1. Place slide on stage
  2. Start with lowest magnification
  3. Switch on light
  4. Move stage close to lens
  5. Turn focusing knob to move slide away
  6. Focus image using fine focus
  7. Change objective lens and repeat
• What is the overall magnification formula?

  Eyepiece magnification x Objective magnification
• Why must objects be thin to view under a light microscope?

  So light can pass through
• What happens to cells as an organism develops?

  Cells differentiate into specialized types
• What are stem cells?

  Undifferentiated cells
• Where do stem cells from human embryos come from?

  Can be cloned and differentiate into most types
• What is the difference between adult and embryonic stem cells?

  Adult stem cells are less versatile
• What is meristem tissue in plants?

  Tissue that can differentiate throughout life
• What are the pros and cons of using embryonic stem cells?

  Pros:

  • Can become any type of cell
  • Painless to obtain
  • Can create many embryos

  
  

  Cons:

  • No consent from embryo
  • Death to embryo
  • Less reliable
• What are the pros and cons of using adult stem cells?

  Pros:

  • Patient can give consent
  • Quick recovery
  • Reliable technique

  
  

  Cons:

  • Limited to some diseases
  • Procedure can be painful
  • Risk of infection
• How can stem cells be used in medicine?

  Treat conditions like paralysis and diabetes
• What is therapeutic cloning?

  Embryo made with same genes as patient
• What are the risks associated with therapeutic cloning?

  • Risks of viral infection
  • Potential life destruction
  • Poor success rate
• How are stem cells from plant meristem tissue used?

  • Make quick and economical clones
  • Protect rare species from extinction
• What is the nucleus in a cell?

  Part where genetic information is found
• What are genes?

  Short sections of DNA on a chromosome
• What is DNA?

  A polymer made of two strands
• What are chromosomes?

  Long molecules of DNA containing genes
• How many chromosomes do humans have in body cells?

  46 chromosomes