Q8 DNA/ Microscope

Question 1

Prepare an ANIMAL cell

Answer 1

• Swab cheek with cotton bud, smear on slide
• add methylene blue to stain nucleus
• using a mounted needle, cover slip at 45° angle to prevent air bubbles

Question 2

Prepare and examine an unstained PLANT cell

Answer 2

• Remove onion epidermis, place in petri dish of water, prevent drying out
• transfer to slide
• Cover slip at 45° angle using mounted needle to prevent air bubbles
  Examine:
  -Low magnification
  -coarse focus)
  -fine focus
  -repeat higher magnification.

Question 3

To isolate DNA from a plant tissue

Answer 3

Method:
• Add salt + washing-up liquid to distilled water.
• Chop kiwi using knife, add to beaker and pour in salty washing up liquid mixture
• Heat at 60°C for 15 min. Cool mixture.
• Blend (3 sec), filter using coffee filter paper
• Transfer filtrate to boiling tube and add protease enzyme, mix gently.
• Trickle ice-cold ethanol at angle.
• Using the glass rod, gently draw the DNA out from the alcohol.

Question 4

EXAMINE an animal cell

Answer 4

• place slide on stage and secure with clips
• Low magnification first, use coarse focus to get rough image
• use fine focus for. A more precise image
• Repeat higher magnification

Question 5

Prepare a stained plant cell

Answer 5

• Remove onion epidermis, place in petri dish of water, prevent drying out
• transfer to slide
• add few drops of iodine to make cells more visible
• Cover slip at 45° angle using mounted needle to prevent air bubbles and protect specimen

Question 6

Examine a stained plant cell

Answer 6

Place slide on the stage, secure it with the clips.
Low magnification
Use the course focus to get a rough image.
Use the fine focus for precise image.
Repeat this at a higher magnification.