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GCSE Biology > Biology Practicals (Paper 1 atm Only) > Flashcards

Biology Practicals (Paper 1 atm Only) Flashcards

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1
Q

Test for Glucose/Sugar

Add ________’s Solution to food sample
Place in __ degrees C water ____ for _ minutes
Sugar present = colour change from ____ to brick __
_____/Orange/______ = ________ result but _____ concentration of sugar present

A

Add Benedict’s Solution to food sample
Place in 80 degrees C water bath for 5 minutes
Sugar present = colour change from blue to brick red
Green/Orange/Yellow = positive result but lower concentration of sugar present

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2
Q

Test for Starch

Add few drops ______ Solution to food sample on ________ tile
Starch present = colour change from ______ to ____/_____

A

Add few drops Iodine Solution to food sample on spotting tile
Starch present = colour change from orange to blue/black

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3
Q

Test for Proteins

If sample _____ - add _cm^3 _____ to food sample and _____
Add _____ volume of dilute _________ _________ and _____
Add _ drops _% ______ _______ solution
Protein present = pale ______ colour present

A

If sample solid - add 2cm^3 water to food sample and shake
Add equal volume of dilute potassium hydroxide and shake
Add 2 drops 1% copper sulfate solution
Protein present = pale purple colour present

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4
Q

Test for Lipids

________ Test
Place food sample in ____ ____
Add pure _______
_____ to _______ any lipid in _______
Add _____ volume of _____
Lipids present = ________ forms = cloudy _____ colour

A

Emulsion Test
Place food sample in test tube
Add pure ethanol
Shake to dissolve any lipid in alcohol
Add equal volume of water
Lipids present = emulsion forms = cloudy white colour

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5
Q

What enzyme digests starch into

A

Enzyme = Amylase
Broken down to Maltose

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6
Q

A variable to control with enzyme activity

A

Temperature - optimum temperature most effective temperature for enzymes

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7
Q

[6] Design investigation to find best temperature for removing protein stains by using washing powder that contains protease enzyme.

A

Use a range of temperatures from 20-60 degrees C at 5 degrees C intervals
Use same concentration of enzyme and mass of washing powder
Repeat each temperature for the practical 3 times and calculate mean
Measure area of the stain 30 minutes after cleaning it
Ensure same pH of washing powder or same type of clothing material
Ensure same area or mass of protein stain

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8
Q

How does temperature affect rate of diffusion

A

@Higher Temperatures
Molecules = more kinetic energy
So move faster
Diffusion happens faster

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9
Q

How does distance affect rate of diffusion

A

Greater Distance
= Smaller surface area to volume ratio
Substance has less area to diffuse across
So slower diffusion rate

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10
Q

How does visking tubing allow osmosis to occur

A

Only allows small soluble molecules to pass
Such as Glucose and Water
So Osmosis can occur

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11
Q

How to investigate rate of osmosis with visking tubing practical

A

Change concentration of sucrose solution in visking tubing
Or temperature of water
Height of liquid rises into capillary tube if osmosis faster
Height falls if osmosis slower

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12
Q

How can potato chips be used to measure rate of osmosis

A

Placed in sucrose or salt solutions of different concentrations
Osmosis occurs until water potential of tissue + solution = same
Measure the mass change

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13
Q

Why are you drying cylinders of potato before measuring the final mass of potato after practical

A

Remove surface moisture
That would alter results
So valid comparison could be made

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14
Q

Define Osmosis

A

Movement of water molecules from high to low water potential via a partially permeable membrane

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15
Q

For potato osmosis practical:
If solution has a high water potential then….

A

Water will move into potato chip
Mass of chips will increase

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16
Q

For potato osmosis practical:
If solution has a low water potential then….

A

Water will move out of potato chip
Mass will decrease

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17
Q

Plant cells are described as ______ when soaked in pure water

A

turgid

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18
Q

Plant cells are described as ___________ when soaked in concentrated salt or sugar solution

A

plasmolysed

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19
Q

Animals cells (rbc) described as _____ when they are full of water molecules

A

Lysed
Rbc can burst
They have no cell wall to protect cell

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20
Q

Animals cells (rbc) described as _________ when they not filled with water molecules

A

Shriveled

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21
Q

To investigate photosynthesis of a leaf why is leaf placed in boiling water

A

Kills the leaf
Stops any chemical reactions occuring

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22
Q

To investigate photosynthesis of a leaf why is leaf placed in hot ethanol

A

The boiling ethanol dissolves chlorophyll and removes green colour from leaf
Turns white to easy see change colour

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23
Q

To investigate photosynthesis of a leaf why do you rinse the leaf

A

Rehydrate and soften leaf

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24
Q

To investigate photosynthesis of a leaf how do you remove CO2 before testing

A

Destarch leaf
Expose one side of leaf to sodium hydroxide
Absorb CO2 in air

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25
To investigate photosynthesis of a leaf why do you place leaf in dark room before experiment
Destarch leaf Free from starch at the start of the experiment
26
To investigate photosynthesis in pondweed how would you change light intensity
Move distance of a lamp
27
To investigate photosynthesis in pondweed how would you vary CO2 concentrations
Use different masses of sodium bicarbonate to vary concentrations
28
To investigate photosynthesis in pondweed how would you measure rate more accurately
Collect gas in inverted cylinder Measure volume of oxygen evolved per unit time
29
Tell me photosynthesis equation
6CO2 + 6H2O --> C6H12O6 + 6O2
30
[6] Design investigation to determine the rate of photosynthesis changes as light intensity changes
Change light intensity by changing distance lamp is from pondweed Use same species of pondweed Repeat each distance 3 times and calculate an average Measure amount of bubbles produced over 5 minutes Ensure same size of plant/number of leaves Ensure same volume of water/concentration of CO2
31
In the pea seed respiration practical how could you show energy has been released
Measure the change in temperature in each thermos flask Heat not transferred to surroundings as flask insulated Only see temperature rise in alive pea seed conditions as other seeds are dead so only alive seeds are releasing energy
32
In the pea seed respiration practical how could you show CO2 produced
Use delivery tube to collect any produced gas in each flask Gas can be bubbled through limewater if CO2 present = lime water would go from clear to cloudy
33
In the pea seed respiration practical why are there 2 thermos flasks
One flask is a control experiment Identical to original experiment But without independent variable (be specific to question in exam for variable)
34
In the pea seed respiration practical why are peas soaked in Milton fluid
Peas are soaked in the bleach Kills any bacteria As bacteria would respire and affect results
35
[6] Adding water to a powder called sodium metabisulphite will release sulphur dioxide gas. Devise a laboratory investigation to find out the effect of sulfur dioxide gas on the heat release by germinating seeds
Change conditions of seeds One batch exposed to SO2 and one not exposed to SO2 Use same species/type of seed Repeat each condition 3 times Measure temperature change Using thermometer Ensure same thermos flask to contain seeds Ensure same moisture/humidity/light intensity/starting temperature
36
State an alternative solution to measure CO2 concentration
Use hydrogen carbonate indicator Turns yellow when CO2 concentration increases Stays red if no CO2 present
37
In concentration of CO2 of inhaled/exhaled air practical give 2 possible solutions to test for it
Limewater Hydrogen Carbonate Indicator
38
State 2 differences between inhaled air and exhaled air
Concentration of carbon dioxide (low in inhalation, high in exhalation) Exhaled air is warmer than Inhaled air
39
Why does breathing rate increase during exercise
Increased concentration of CO2 in blood Carbon dioxide excreted more rapidly Increases heart rate Increased breathing rate supplies more O2 to muscles for aerobic respiration
40
How can we tell if a seed has germinated
Radicle/shoot/root is seen
41
Why is oxygen needed for germination
For aerobic respiration to release energy
42
Why is warmth needed for germination
Optimum temperature for enzymes
43
Why is water needed for germination
To activate enzymes
44
What happens to ovary after fertilisation
Ovule becomes a seed Ovule wall becomes a seed coat Ovary becomes a fruit
45
Why do fewer seeds germinate when stored in wet and warm conditions
There are more bacteria in these conditions so seeds could get diseased
46
A student investigates the oxygen absorbed by germinating seeds at different temperatures Suggest why the student opens the tap after obtaining one set of results
To repeat readings Allow oxygen in for aerobic respiration Prevent anaerobic respiration
47
A student investigates the oxygen absorbed by germinating seeds at different temperatures What is the function of soda lime
Absorbs CO2
48
Why is the rate of oxygen absorption greater at 22 degrees C than 12 degrees C
More respiration Enzymes have more kinetic energy More collisions So more enzyme substrate complexes are formed
49
Aerobic Respiration Equation
C6H12O6 + 6O2 --> 6CO2 + 6H2O
50
Anaerobic Respiration Equation in Fungi and Plants
Glucose --> Ethanol + Carbon Dioxide
51
Anaerobic Respiration Equation in Animals
Glucose --> Lactic Acid
52
[3] Describe a method to measure mean number of weeds in each field
Use a quadrat Count number of weeds in quadrat Use random coordinates in fields to place quadrat down in Repeat process 3 times
53
[5] Discuss if biological control is better at controlling weeds than chemical control (pesticides)
*Before using own knowledge compare data in the table for discuss questions Biological control doesn't need to be reapplied - insects can reproduce Biological control less risk of pollution Biological control less risk of resistance but Chemical control - weeds can grow resistance to pesticides Biological control is specific - doesn't affect other food chains Biological control methods cause no bioaccumulation (no harmful chemicals built up in weed tissue) But Biological control could become a pest Chemical control can contaminate soil
54
Describe a method to measure the percentage of a stone wall covered by lichen
Measure area of lichen Measure total area of stone Repeat 10 times and calculate mean
55
Natural Selection example....
Plant with a short growing season survive drought
56
Eutrophication example....
Growth of algae in rivers polluted by fertiliser
57
Insect pollination example....
Pollen transferred from one plant to another by an insect
58
Active Transport example....
Absorption of nitrate ions from soil using ATP
59
Describe a method the scientist could use to compare the population of the grass species at 50 m and 100 m from the mine
Use tape measure And quadrat Count the number of species on quadrat Repeat 10 times
60
In the anaerobic respiration of glucose and yeast suspension practical why is layer of oil added
Prevent entry of oxygen Ensuring anaerobic respiration
61
In the anaerobic respiration of glucose and yeast suspension practical how could you measure rate of respiration
Number of bubbles produced in 30 minutes in test tube of limewater
62
In the anaerobic respiration of glucose and yeast suspension practical why does a student boil and cool glucose before yeast added
Boiled To remove oxygen Kill bacteria Then Cooled so enzymes don't denature And so yeast doesn't die
63
In the anaerobic respiration of glucose and yeast suspension practical how could you modify experiment instead of counting bubbles.
Use a Measuring cylinder To measure volume
64
In the anaerobic respiration of glucose and yeast suspension practical give function of the water bath
Control and maintain constant temperature
65
Explain how named conditions in industrial fermenter are controlled
Steam applied before usage kill unwanted microorganisms leaving only water Stirrers ensure mixture is evenly distributed Cooling Jacket maintains optimum temperature stops enzymes denaturing Air filters prevent contamination and keep aseptic conditions
66
Explain how bacteria have evolved so antibiotics are less effective
Mutation in bacteria Can create a resistance to the antibiotics Only resistant bacteria survive Resistant bacteria reproduce Pass on the allele So resistant bacteria increase in population
67
Explain rate of respiration of yeast as temperature increases from 45 degree C to 60 degrees C.
Increased temperature = breaks bonds Change in shape of active site Enzyme denatures Substrate can no longer bind with enzyme

GCSE Biology (11 decks)

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