Biology

• How do we calculate the total magnification of a microscope?

  Eyepiece lens x Objective lens magnifying power
• State the equation that links magnification, image size and actual size.


  I = AM
• Define 'resolution'.


  The ability to distinguish between two separate points that are very close together
• Which type of microscope has higher magnification and resolving power - Light or electron?

  Electron microscopes
• Why does the tissue sample need to be stained before looking at it under the microscope?

  To visualise/see structures clearly
• Which objective lens should we start using?

  Low power objective lens
• What is the function of the diaphragm of the light microscope?

  To control the amount of light passing through the sample
• Which focus knob should be used during low and medium power magnification?

  Coarse focus knob
• Which focus knob should be used during high power magnification?

  Fine focus knob
• Why must we not use the coarse focus knob during high power magnification?

  It moves the stage by too much, may break the lens and the slide
• It is acceptable to draw sketchy and feathery lines for biological drawing. True or false?

  FALSE
• Biological drawings must always be labelled. True or false?

  TRUE
• Biological drawings must occupy at least half the size of the space provided. True or false?

  TRUE
• Colouring and shading is allowed in biological drawings. True or false?

  FALSE
• What is the function of a scale bar?

  To allow us to calculate the actual size of the sample using I=AM
• State the function of the nucleus.


  Controls all activities of the cell, contains genetic information
• State the function of the cytoplasm.

  Site for chemical reactions to take place
• State the function of the cell membrane.


  Controls what substances go in and out of the cell
• State the function of the mitochondria.

  Site of aerobic respiration, releasing energy
• State the function of the ribosomes.

  Site of protein synthesis
• State the function of the cell wall.

  Strengthens the cell, provide support
• State the function of the chloroplasts.

  Contain chlorophyll, absorb light to do photosynthesis
• State the function of the permanent vacuole.

  Contains cell sap to keep plant cells rigid, provide support
• State three differences between animal and plant cells.

  Plant cells have chloroplasts, permanent vacuole and cellulose cell wall. Animal cells do not
• What substance makes up plants' cell walls?

  Cellulose
• Convert 5mm to µm.

  5000µm
• State a key difference between prokaryotes and eukaryotes.

  Prokaryotes do not have a nucleus. Eukaryotes do.
• State one organism that is prokaryotic.

  Bacteria
• Prokaryotes have a cell wall. True or false?

  TRUE
• Some bacteria have an extra layer on top of their cell walls. What is the name of that layer?

  Slime capsule
• Where does the genetic material of a prokaryotic cell exist?

  Cytoplasm
• What is a difference between prokaryotic and eukaryotic DNA?

  Prokaryotic DNA is circular; Eukaryotic DNA is linear
• What is the name of extra small DNA rings found in some prokaryotes?

  Plasmid
• What is the function of flagella?

  To allow the cell to swim and move around
• State a difference between animal cells and bacteria.

  A: No cell wall and plasmid, linear DNA; B: Cell wall and plasmid, circular DNA
• State a similarity between plant cells and bacterial cells.

  Both have cell walls (but different material)
• What is the function of the slime capsule?

  Protect the cell
• Explain the use of a tail in sperm cells.


  To swim and move around (to reach the egg)
• Why do sperm cells have lots of mitochondria?

  To provide lots of energy for swimming
• What is the structure of a sperm cell that contains digestive enzymes to break down the surface of an egg cell?

  Acrosome