Y9 Biology - rp1

Apparatus (8)

Small piece of onion, white tile, forceps, microscope slide, coverslip, microscope, iodine solution, distilled water

Step 1 (…apparatus)

Collect the apparatus

Step 2 (…on the slide)

Put a small drop of water on the slide

Step 3 (Use … to … layer of …)

Use forceps to peel off a layer of epidermal tissue

Step 4 (…on the … on the …)

Place it on the water on the slide

Step 5(…drop… onion…)

Place a drop of iodine on the onion tissue

Step 6(carefully… .slip…angle to avoid…)

Carefully cover the onion tissue with a coverslip at a 45* angle to avoid bubbles

Step 7(Use…to…from the coverslip. Don’t move…)

Use tissue to soak up liquid from the edge of the coverslip. Don’t move the coverslip

Step 8(Turn…to…)

Turn the nosepiece to the lowest power objective lens

Step 9(looking from … turn the … so that the bottom of … almost …)

Looking from the side (not through the eyepiece), turn the coarse adjustment knob so that the bottom of the objective lens almost touches the slide

Step 10 (Looking …, turn the … to move the … … … the … until the cells …)

Looking through the eyepiece use the coarse adjustment knob to move the stage away from the lens until the cells are in focus

Step 11(if … use the … to bring the …)

If necessary use the fine adjustment knob to bring the cells into clear focus

Step 12(…to observe …)

Switch to a higher objective lens to see cells in more detail

Why do we look from lower objective lens first

Wider field of viewing, and so that the slide doesn’t get damaged

Why to stain the specimen with water

Keep it hydrated

Why is coarse adjustment knob used before fine adjustment knob

Initial rapid adjustment made to bring a specimen into approximate view - therefore you need to use lowest power first