H2 Biology Practical Notes (Planning Question)
(A) Theory & Hypothesis
(i) Explanation of Theory/Experimental Design
● Explain why IDV affects DV
● How to measure DV/data with specific apparatus, how to determine DV from data or how
measured data will reflect DV
(ii) Hypothesis
● How change in IDV affects DV; if __ is no longer limiting, no further increase in __
(B) Procedure
(i) Variables (Independent, Dependent, Controlled x2)
● Examples of CVs:
○ Equilibration time/temperature
○ Incubation time/temperature
○ Reaction time/temperature
○ Volume of __
○ Duration of staining
○ Species/age of __
○ Stirring/mixing of reaction mixture
(ii) Variation of Independent Variable
● Dilution table (if IDV is concentration)
○ Using a __ (e.g. 5 cm3 syringe, 100 cm3 measuring cylinder), dilute __ (e.g. 0.1 mol
dm-3 Na3PO4 stock solution) with distilled water to obtain (volume) of __ of varying
concentrations
Concentration of Na3PO4 Volume of solutions/cm3
solution/mol dm-3 Distilled water 0.1 mol dm-3 Na3PO4 solution Total
0.00 (control) 200 0 200
0.02 160 40 200
0.04 120 80 200
0.06 80 120 200
0.08 40 160 200
0.10 0 200 200
● Temperature of water bath
○ Prepare water baths of varying temperatures (list temperatures used) by mixing
boiling water and tap water in 500 cm3 beakers
○ Monitor temperature of each water bath using a thermometer, adding boiling
water or tap water to maintain the temperature when necessary
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, (iii) Methods (including Control of Controlled Variables)
● Specify appropriate quantities (e.g. volume, concentration) of materials (sufficient to
perform all replicates and repeats)
● Specify appropriate apparatus required
● Detailed, labelled diagram of experimental setup
(1) Equilibration of solutions
a) Using the thermostatically controlled water bath, equilibrate (volume) of __ to
(temperature, e.g. 30oC) for (duration, e.g. 10 min) as timed using a stopwatch; Monitor the
temperature using a thermometer
b) Using the thermostatically controlled water bath, equilibrate (volume) of __ to
(temperature, e.g. 30oC) for (duration, e.g. 10 min) as timed using a stopwatch; Monitor the
temperature using a thermometer
c) Upon equilibration of __ and __, stir well using a glass rod
● Reactions (enzymes): using a 5 cm3 syringe, dispense __ of __ into a test-tube; using a 5
cm3 syringe, dispense __ of __ into the test-tube; shake to mix the contents thoroughly
(2) Use of weighing balance
(a) (if applicable) dab the __ dry with paper towels
(b) Tare the balance by pressing the re-zero button before use
(c) Weigh accurately and record mass to nearest 0.1 g/weigh approximately __ g of __
(2) Root tip squash
● Maceration and staining of root tips
a) Incubate the onion over 48h at a constant 30oC in a thermostatically-controlled water
bath with thermometer
b) Select one onion plant and dry the root tips with a paper towel
c) Submerge the onion root tips in HCl in the 55oC thermostatically-controlled water bath for
5 min to soften the roots; rinse the root tips with water
d) Place the onion plant into a vial of toluidine blue solution/acetocarmine solution for 30s
e) Rinse the roots with water until the water is colourless
● Mounting of sample
f) Use the scalpel to cut a 1mm length of root tip tissue on a white tile
g) Using the forceps, place the root tip on a glass slide and place a coverslip on top
h) Use the wooden end of the mounting needle to squash the root tip (wipe excess stains off
slide with filter paper)
(3) Preparing beetroot discs (e.g. for membrane permeability)
a) Cut out cylinders of beetroot using a cork borer of 1-cm diameter
b) Cut 100 pieces of 2 mm thick discs from the cylinders aligned against a 15-cm ruler using
a scalpel
c) Rinse the discs in running water until the water is colourless
(4) Preparing yeast/enzyme-alginate beads
a) Using a 10 cm3 syringe, add 20 cm3 of __ calcium chloride solution into a boiling tube
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(A) Theory & Hypothesis
(i) Explanation of Theory/Experimental Design
● Explain why IDV affects DV
● How to measure DV/data with specific apparatus, how to determine DV from data or how
measured data will reflect DV
(ii) Hypothesis
● How change in IDV affects DV; if __ is no longer limiting, no further increase in __
(B) Procedure
(i) Variables (Independent, Dependent, Controlled x2)
● Examples of CVs:
○ Equilibration time/temperature
○ Incubation time/temperature
○ Reaction time/temperature
○ Volume of __
○ Duration of staining
○ Species/age of __
○ Stirring/mixing of reaction mixture
(ii) Variation of Independent Variable
● Dilution table (if IDV is concentration)
○ Using a __ (e.g. 5 cm3 syringe, 100 cm3 measuring cylinder), dilute __ (e.g. 0.1 mol
dm-3 Na3PO4 stock solution) with distilled water to obtain (volume) of __ of varying
concentrations
Concentration of Na3PO4 Volume of solutions/cm3
solution/mol dm-3 Distilled water 0.1 mol dm-3 Na3PO4 solution Total
0.00 (control) 200 0 200
0.02 160 40 200
0.04 120 80 200
0.06 80 120 200
0.08 40 160 200
0.10 0 200 200
● Temperature of water bath
○ Prepare water baths of varying temperatures (list temperatures used) by mixing
boiling water and tap water in 500 cm3 beakers
○ Monitor temperature of each water bath using a thermometer, adding boiling
water or tap water to maintain the temperature when necessary
Copyright © 2019 tonyndr
, (iii) Methods (including Control of Controlled Variables)
● Specify appropriate quantities (e.g. volume, concentration) of materials (sufficient to
perform all replicates and repeats)
● Specify appropriate apparatus required
● Detailed, labelled diagram of experimental setup
(1) Equilibration of solutions
a) Using the thermostatically controlled water bath, equilibrate (volume) of __ to
(temperature, e.g. 30oC) for (duration, e.g. 10 min) as timed using a stopwatch; Monitor the
temperature using a thermometer
b) Using the thermostatically controlled water bath, equilibrate (volume) of __ to
(temperature, e.g. 30oC) for (duration, e.g. 10 min) as timed using a stopwatch; Monitor the
temperature using a thermometer
c) Upon equilibration of __ and __, stir well using a glass rod
● Reactions (enzymes): using a 5 cm3 syringe, dispense __ of __ into a test-tube; using a 5
cm3 syringe, dispense __ of __ into the test-tube; shake to mix the contents thoroughly
(2) Use of weighing balance
(a) (if applicable) dab the __ dry with paper towels
(b) Tare the balance by pressing the re-zero button before use
(c) Weigh accurately and record mass to nearest 0.1 g/weigh approximately __ g of __
(2) Root tip squash
● Maceration and staining of root tips
a) Incubate the onion over 48h at a constant 30oC in a thermostatically-controlled water
bath with thermometer
b) Select one onion plant and dry the root tips with a paper towel
c) Submerge the onion root tips in HCl in the 55oC thermostatically-controlled water bath for
5 min to soften the roots; rinse the root tips with water
d) Place the onion plant into a vial of toluidine blue solution/acetocarmine solution for 30s
e) Rinse the roots with water until the water is colourless
● Mounting of sample
f) Use the scalpel to cut a 1mm length of root tip tissue on a white tile
g) Using the forceps, place the root tip on a glass slide and place a coverslip on top
h) Use the wooden end of the mounting needle to squash the root tip (wipe excess stains off
slide with filter paper)
(3) Preparing beetroot discs (e.g. for membrane permeability)
a) Cut out cylinders of beetroot using a cork borer of 1-cm diameter
b) Cut 100 pieces of 2 mm thick discs from the cylinders aligned against a 15-cm ruler using
a scalpel
c) Rinse the discs in running water until the water is colourless
(4) Preparing yeast/enzyme-alginate beads
a) Using a 10 cm3 syringe, add 20 cm3 of __ calcium chloride solution into a boiling tube
Copyright © 2019 tonyndr
