B1 (version 2)

• What type of cells are bacterial cells examples of?

  Prokaryotic cells
• What are examples of eukaryotic cells?

  Plant and animal cells
• What structures do all eukaryotic cells have?

  A cell membrane, cytoplasm, and genetic material enclosed in a nucleus
• How do prokaryotic cells differ in size compared to eukaryotic cells?

  Prokaryotic cells are much smaller than eukaryotic cells
• What is the genetic material structure in prokaryotic cells?

  It is a single DNA loop and may include plasmids
• What are orders of magnitude used for?

  To give a general idea of how big or small something is
• How do you find an object's order of magnitude?

  Write its size in standard form and identify the power of 10
• What is the order of magnitude of a cell that is $4 \times 10^{-4} \text{ m}$ wide?


  $10^{-4} \text{ m}$
• What is the order of magnitude of a bacterial cell that is $3.4 \times 10^{-6} \text{ m}$ wide?


  $10^{-6} \text{ m}$
• How do you find the order of magnitude difference between two objects?

  Find the difference in their powers of 10
• If a small animal cell has a length of $10 \mu m$ and a large plant cell has a length of $100 \mu m$, what is their order of magnitude difference?


  1 jump = 1 order of magnitude difference
• What are the main components of most plant cells?

  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Mitochondria
  • Ribosomes
  • Chloroplasts
  • Cell wall (made of cellulose)
• What are the main components of most animal cells?

  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Mitochondria
  • Ribosomes
  • Vacuole (filled with cell sap)
• What is the function of the nucleus in a cell?

  It controls all the activities in the cell and contains genes in chromosomes
• How wide is the nucleus generally?

  Around $10 \mu m$
• What is the cytoplasm?

  A jelly-like substance where organelles are suspended and many chemical reactions take place
• What does the cell membrane do?

  It controls the substances that enter and leave the cell
• Where does aerobic respiration take place in a cell?

  In the mitochondria
• How long and wide are mitochondria generally?

  Around $1 \mu m$ long and $0.5 \mu m$ wide
• What is the function of ribosomes?

  Where protein synthesis takes place, making all the proteins needed in the cell
• What is the cell wall made of in plant and algal cells?

  Cellulose
• What do chloroplasts contain and what is their function?

  They contain chlorophyll, which absorbs light for photosynthesis
• How long are chloroplasts generally?

  Around $3-5 \mu m$ long
• What is the function of the vacuole in plant cells?

  It keeps the cell rigid to support the plant
• How do you determine the real size of a cell or sub-cellular structure?

  Real size of cell = Real size of bar x measured size of cell / Measured size of bar
• When were lenses developed in Italy?

  14th century
• Who made the first microscope and when?

  Hans and Zacharias Janssen in 1590
• Who studied objects with a microscope in 1667?

  Hooke
• Who used a microscope to observe cells in 1675?

  Leeuwenhoek
• What did Lister discover in 1830?

  Combining lenses makes a clearer image
• Who developed the electron microscope and when?

  Ruska in 1938
• How does an electron microscope differ from a light microscope?

  An electron microscope has much higher magnification and resolving power
• What is magnification?

  How much bigger you can make an image
• What is resolution?

  How much detail you can see on an image
• What is the formula for magnification?

  Magnification = size of image ÷ size of real object
• What are the steps for using a microscope?

  1. Put the slide on the microscope stage.

  2. Select the lowest power objective lens.

  3. Adjust the lens towards the slide using the coarse adjustment knob.

  4. Look through the eyepiece and adjust for focus.

  5. Use the fine adjustment knob for clear focus.

  6. Switch to a higher power lens and refocus.

  7. Draw and label the cells.

  8. Write the magnification underneath the drawing.
• How do you determine the magnification of an image with a scale bar?

  Measure the size of the scale bar and divide by the size it tells you
• How do you find the real size of a cell from its image size?

  Divide the measured length of the cell by the magnification
• What happens to animal cells as they differentiate?

  They acquire different sub-cellular structures to carry out specific functions
• How does differentiation differ in animal and plant cells?

  Most animal cells differentiate early, while many plant cells can differentiate throughout life