Required practicals Flashcards
microscopy, osmosis, photosynthesis (30 cards)
What is the required practical for microscopy in biology?
Use a light microscope to observe, draw, and label a plant cell. A magnification scale must be included.
What apparatus is needed for the microscopy practical?
Microscope, onion, slide, coverslip, forceps, iodine solution.
What is the first step in the microscopy method?
Peel off a thin layer of skin from the inner surface of a piece of onion.
How should the onion layer be placed on the slide?
Use forceps to put this thin layer on a slide. Make sure it is flat.
What should be added to the onion tissue on the slide?
Put 1 drop of iodine solution onto the onion tissue.
What is the next step after adding iodine solution?
Carefully lower a coverslip onto the slide.
How do you handle excess liquid on the slide?
Use a piece of paper to soak up excess liquid.
Where should the slide be placed for observation?
Put the slide on the microscope stage.
Which objective lens should be used first?
Use the lowest power objective lens x4.
How do you focus the cells under the microscope?
Turn the coarse adjustment knob so the lens moves away from the slide.
What should you do after focusing with the lowest power lens?
Rotate the nosepiece to a higher lens.
What should be done after observing the cells?
Make a clear, labelled drawing of the cells and components.
What should be included under the drawing?
Write the magnification under your drawing.
What is the required practical for investigating osmosis?
Investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue.
What type of tissue is used in the osmosis experiment?
Potato tissue.
How is the potato tissue prepared for the osmosis experiment?
Cut into equal sized cylinders.
What solutions are used in the osmosis experiment?
Sugar solution and distilled water.
How long are the potato cylinders left in the solutions?
Overnight.
What measurements are compared in the osmosis experiment?
Changes in length and mass.
What apparatus is needed for the osmosis experiment?
Potato, potato cutter, boiling tubes x5, test tube rack, sugar solution, distilled water.
What are the concentrations of sugar solution used in the experiment?
0.75 mol/dm³, 0.50 mol/dm³, 0.25 mol/dm³.
What is the first step in the method?
Cut five potato cylinders of the same diameter.
What should be done to the potato cylinders after cutting?
Trim the ends so that they are all the same length
What measurements need to be taken for each potato cylinder?
Accurately measure and record the length and mass of each cylinder.
