CP 1: Looking at Cells

• What is an important biological skill mentioned in the study material?

  The ability to draw, label, and annotate biological specimens

  
• What are the benefits of active recording in biology?

  • Aids memory retention
  • Helps in understanding concepts
  • Provides a permanent record of observations
• What are the three statements about learning mentioned in the study material?

  I hear and I forget, I see and I remember, I do and I understand
• Why is it not necessary to draw everything seen in microscope slides?

  You only need to include enough information to make your drawing useful
• What should you do if you make a mistake while drawing?

  Rub it out and try again
• What shape are animal cells often drawn as?

  As a circle
• What is the only obvious structure in a white blood cell that needs to be drawn?

  The nucleus
• What should be used to draw label lines?

  A ruler
• Why should label lines not overlap?

  Because it can be confusing
• What should labels be written in?

  Neat handwriting
• What should you do if you expect to see a structure that isn’t visible?

  Add a note about it
• What should be included to show the size of the cell?

  A magnification or scale
• What are the steps to draw and label a fat cell from a slide?

  • Draw clean lines with a sharp pencil
  • Draw only what you see
  • Use a ruler for label lines, ensuring they don’t overlap
  • Label the important features of the cell
• What are the steps to draw and label a cell from Elodea pondweed?

  • Draw clean lines with a sharp pencil
  • Draw only what you see
  • Use a ruler for label lines, ensuring they don’t overlap
  • Label the important features of the cell
• How should the microscope be carried?

  In two hands
• Where should the microscope be placed?

  On a solid flat surface
• What should be checked before using the microscope?

  That the light is switched on and plugged in
• What should be done when using high power on the microscope?

  Look at the slide and lens from the outside and bring them together
• What should be done when clearing up the microscope?

  The smallest lens should be in place and the stage wound fully up
• What is the aim when preparing a slide of cheek cells for viewing under a microscope?

  • Be able to prepare a slide of cheek cells (specimen) for viewing
  • Follow instructions carefully

  
• What should you do if you need help focusing the microscope?

  • Try to focus it yourself first
  • Ask for help if needed
• What are the main structures you should have seen in the cheek cell?

  Nucleus, Cell Membrane, Cytoplasm
• What should you do when preparing a slide of plant cells for viewing under a microscope?

  • Use a stain if necessary
  • Follow the instructions carefully
• What is the aim of the investigation described in the study material?

  To investigate biological specimens using microscopes, including magnification calculations and labelled scientific drawings.
• What equipment is needed for the investigation?

  • Light microscope
  • Microscope slide
  • Cover slip
  • Onion
  • Forceps
  • Iodine solution
  • White tile
  • Scalpel
  • Any other prepared plant and animal cell slides
• Why is iodine solution used in the method?

  To stain the cells so that internal structures like the nucleus become visible.
• What is the first step in the method for preparing the onion slide?

  Peel off an epidermal layer on the onion using forceps.
• How should the cover slip be placed on the slide?

  By first placing one edge down on the slide and slowly lowering the other side using forceps to avoid air bubbles.
• What should be done to remove excess stain from the slide?

  Soak it with paper towels.
• What is the purpose of using the coarse adjustment knob before looking into the eyepiece?

  To raise the stage until the cover slip just touches the objective, helping to avoid breaking the slide.
• What should you do after selecting a low power objective?

  Use the coarse adjustment knob to raise the stage until the cover slip just touches the objective.
• What is the next step after focusing the image with the low power objective?

  Turn the nosepiece to select a high power objective and repeat the focusing process.
• What should be included in the labelled drawing of the cells?

  Features such as the cell wall and nucleus, along with the magnification.
• What safety precautions should be taken when handling the iodine solution?

  Wear safety goggles.
• What should you do if a slide breaks?

  Be careful with the broken glass.
• What are the steps involved in preparing a microscope slide of an onion?

  1. Peel off an epidermal layer using forceps.
  2. Mount on a slide with a drop of water.
  3. Add iodine solution to stain cells.
  4. Place cover slip carefully.
  5. Remove excess stain with paper towels.
  6. Place slide on microscope stage.
  7. Use coarse adjustment to focus.
  8. Switch to high power and fine-tune focus.
  9. Make a labelled drawing of observed cells.

  10. Repeat with a prepared slide.