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How many steps are there when Demonstrating Osmosis?
- 10 steps
- Soften busking tubing
- Knot one end of each
- Half fill with sucrose
- Half fill with distilled water (control)
- Eliminate air, knot the tops, wash and pat dry
- Tie two ends
- Observe turgidity and record mass
- Hang from glass rod into beaker of distilled water
- Remove, dry, and re-weigh, observe turgidity
- Expected result
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What is the expected result when Demonstrating Osmosis?
Expected result: the visking tubing that was immersed in a less concentrated solution swelled and tubing with distilled water stayed the same as the concentration gradient as the same.
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What equipment is involved when Demonstrating Osmosis?
- Visking tubing
- Funnel (to put solutions into tubing step 3+4)
- Sucrose solution
- Distilled water
- Scale to weigh
- Glass rod
- Beaker (to hold distilled water)
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Why is visking tubing used when Demonstrating Osmosis?
They’re semipermeable membranes that allow some molecules to pass.
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How many steps are there in examining a plant cell, stained and unstained using the light microscope ?
- 12
- Cut onion
- Locate epidermis
- Cut epidermis into small pieces
- Place epidermis into water in petri dish
- Drop of water on slide
- Transfer epidermis into water
- Apply cover slip (45*)
- Lower cover slip
- Dry gently and view the unstained
- To stain, apply iodine and draw across using filter paper
- Examine under microscope
- Expected result: view of plant cell.
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When examining a plant cell, stained and unstained using the light microscope, what is the expected result?
Expected result; view of plant cell.
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When examining a plant cell, stained and unstained using the light microscope, why is ye epidermis placed into water in a petri dish?
To keep it turgid, prevents it getting plasmolysed.
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When examining a plant cell, stained and unstained using the light microscope, what equipment is used?
- Knife (to cut onion in half)
- Petri dish
- Dropper (to place a drop of water on slide)
- Paintbrush (to transfer the epidermis into the water)
- Cover slip
- Mounted needle (to lower cover slip at 45*)
- Tissue (to dry gentle)
- Microscope
- Iodine to stain
- Filter paper (to draw iodine across)
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When examining a plant cell, stained and unstained using the light microscope, what stain is used?
Iodine (applied to one side and drawn across using filter paper)
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When examining an animal cell, stained and unstained, using the light microscope, how many steps are there?
- 12
- Swab inside cheek
- Transfer sample to slide
- Cover sample with water
- Place cover slip at 45*
- Lower cover slip with mounted needle
- Dry slide
- Examine under microscope
- To stain- prepare like steps 1+2
- Cover sample with methylene blue stain
- Wash excess stain
- Apply cover slip (as previously done)
- Expected result- nucleus darker
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When examining an animal cell, stained and unstained, using the light microscope, what equipment is used? (9)
- Inoculating loop (to swab)
- Slide
- Dropper (to drop water on sample)
- Cover slip
- Mounted needle (to lower cover slip)
- Tissue (to dry if necessary)
- Microscope
- Methylene blue stain and dropper
- Wash bottle (to wash excess stain from slide)
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When examining an animal cell, stained and unstained, using the light microscope, what is the expected result?
Expected result: the nucleus stains darker than the cytoplasm as the DNA absorbed more stain.
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When examining an animal cell, stained and unstained, using the light microscope, why is the cover slip placed at the edge of the water at a 45* angle?
To prevent trapping air bubbles which obstruct the view of the cells.
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When examining an animal cell, stained and unstained, using the light microscope, what is used to swab the inside of the cheek?
Inoculating loop
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When conducting a qualitative test for fat, how many steps are there?
- 6.
- Cut up brown paper
- Oil drops on paper A
- Water drops on paper B (control)
- Leave to dry
- Hold up to light
- Expected result- A translucent (positive)
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When conducting a qualitative test for fat, what equipment is needed?
- Brown paper
- Scissors (to cut brown paper)
- Oil
- Water (control)
- Dropper
- A light or window
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When conducting a qualitative test for fat, what is the expected result?
Expected result: paper A positive- translucent spot and B negative- no translucent spot.
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When conducting a qualitative test for protein, how many steps are there?
- 6.
- Label 2 boiling tubes A and B
- Place protein solution into tube A
- Place water into tube B
- Add Biuret reagent into each
- Swirl tubes and observe colour
- Expected result: A positive- lilac/violet, B negative- blue
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When conducting a qualitative test for protein, what is the expected result?
Expected result: A positive - lilac/violet and B negative- blue
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When conducting a qualitative test for protein, what equipment is needed?
- Boiling tubes
- Protein solution
- Water
- Biuret reagent
- Dropper
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What is used to test for protein?
What is the control for this experiment?
- Biuret reagent
- Positive: lilac or violet
- Negative: blue
Control: water
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