Now is the time to start thinking about your ISA.
Let's go through a section one paper.
Question one
Write down your hypothesis.
Explain why you made this hypothesis. [3 marks]
This one is simple.
A hypothesis is a general statement which can be tested.
Your hypothesis needs to link your independent and dependent variable together.
As independent variable increases/decreases dependent variable will increase/decrease.
As to why you made this hypothesis, you are basically explaining your prediction based on some scientific research you have just conducted.
When I was doing some research I found out that insert statement relating to your experiment. This means that/this is because... now give a scientific reason which explains the effect of the independent variable on the dependent variable.
For example, if your ISA is on enzymes then you could say "As the temperature of the amylase increases, the rate at which the starch is broken down also increases".
When I was doing some research I found out that molecules at a higher temperature have more kinetic energy. This means that the molecules are moving faster, so the enzyme molecules are more likely to collide into the starch molecules with enough energy to catalyse the reaction. However, if the temperature rises too high, then the shape of the enzyme will change and the reaction will no longer work.
Question 2
Think about the research that you did to find how to test your hypothesis. Identify two sources that you used for your research.
Which of these sources was the more useful? Why was this source better than the other source?
[3 marks]
This is the same standard question on core, additional and further additional ISAs.
The structure of the answer is always the same:
1. Give your two sources - full website addresses and/or book titles with page numbers and name of author.
http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa/proteins/proteinsrev3.shtml
This will get you the mark, whereas the link below is not accessible by an examiner so wouldn't
School CRL - Science folders - KS4 x WRONG!!
2. Comment on the usefulness of both sources.
Source A was good because it had a simple equipment list and also a risk assessment. Source B was very good because it had a detailed risk assessment and an easy to follow step-by-step method.
3. Now compare them.
Because of this, overall Source B was better than source A because it had the additional detail.
Question 3
In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
From the research you have done, describe in detail how you are going to do your investigation.
You should include:
• the equipment you plan to use
• how you will use the equipment
• the measurements you are going to make
• how you will make the investigation a fair test.
• a risk assessment
[9 marks]
It is so tempting for students to write a wall of text in paragraphs because you're told you'll be marked on QWC. DON'T DO THIS! Who writes a method or a recipe this way?! it is a lot easier for your teacher to mark it and give you FULL marks if you lay it out in an easy to follow style. Use sub-heading to help you.
Equipment
List all equipment needed in a bullet pointed list.
If you haven't listed it, imagine that you wouldn't be given it.
If you need to measure temperature, then ask for a thermometer - you can't do that part of your investigation without it!
- Thermometer 1 oC resolution
- 0.5M amylase solution
- 10ml measuring cylinder
- ..etc
Method
This must be written as a step-by-step list.
1. Do this.
2. Do the next thing.
3. The third thing to be done is....
Variables
List your variables and how you will measure/monitor them. This is vital for the 7-9 marks.
You should aim for at least three control variables.
Independent variable - temperature, measured using a thermometer in degrees centigrade.
Dependent variable - rate of reaction, measured by timing how long the blue-black colour of the iodine starch reaction takes to disappear.
Control variables - Concentration of amylase, a 0.5M concentration will be used each time. Volume of starch solution, a 10ml volume will be used each time and measured using a measuring cylinder. Volume of iodine used, a 3ml volume will be used each time measuring using a dropping pipette.
Risk Assessment
This can be drawn as your Hazard/Risk/Precaution table.
Hazard - this should be an object which could cause harm in certain situations.
Risk - this is what could go wrong with the hazard and how likely this is to happen.
Precaution - this is what step(s) you will take to ensure the risk is minimised.
A hazard is the amylase solution, if spilled the risk of slippage is medium. To avoid this, I will take care when pouring the solution and clean up all spills immediately.
Question 4
This question is difficult to predict and could be about a range of different things to do with your investigation. Common past topics include:
- An alternative method you didn't use.
- A range you have chosen for your independent variable.
- Preliminary investigations.
- A resolution you have chosen for a piece of measuring equipment (usually section 2 though).
Question 5
The easiest two marks on the paper - draw a blank results table.
[2 marks]
You need two headings with units, that's it. Doesn't even matter which way round they go! As long as they match your hypothesis and your method.
Something for your to do!
I have written a method for the 9 mark question. Mark it out of 9 with feedback below.
Provide me with points on at least 3 strengths and 2 areas for improvement:
"Increasing the concentration of enzyme will make it work faster."
1. Take a beaker and 6 test tubes, place the test tubes in the beaker.
2. Add 3cm3 of full fat milk to each tube, this keeps the experiment
constant. The milk is the substrate.
3. Add 2cm3 Sodium Carbonate to each tube, this keeps the
experiment constant and makes the solution alkaline.
4. Add 5 drops of phenolphthalein indicator to each tube, again this
keeps the experiment constant, it will make the solution pink. If
all the tubes have the same volumes of milk, sodium carbonate
and indicator, they should all be of the same colour.
5. Fill the beaker full of 40°C water;
6. Take a stopwatch. Add 1cm3 of water first to test tube 1 then
start the timer. After a minute add 1% enzyme to test tube 2.
After 2 minutes add 2% enzyme to the 3rd test tube and so on.
7. I will do this experiment twice………………………………..
8. I am going to measure how long it takes for the pink solution to
turn white, and record the data in a table
9. On the website it said “This chemical may cause irritation if you
get it into your eyes or breathe it in.”
10. I must make sure I don’t spill it on me and I am going to wear
safety goggles. If I get any on my skin I must wash it off with
water straight away.
Marking Criteria:
6 out of 9 marks.
ReplyDeleteGood Points:
1) You have added units
2) Method is written in an organised sequence
3) Good SPaG
Possible Improvements:
1) Specify what will work better in your hypothesis
2) Include subheadings to increase clarity
3) Write about your variables
4) Step 9 and 10 don't belong in the method. Create a subheading with 'Risk Assessment' written on it. Add more to the risk assessment.
I would give this method 7 out of 8 marks.
ReplyDeleteStrengths:
- Measurements to be made are clearly stated
- Most/all equipment used have also been mentioned.
- The method has been written in a step to step structure and is therefore in a logical and organised sequence.
Improvements:
- State the control variables and how would control them to ensure that it is a fair test.
- The risk assessment is not enough and it should be written out separately so that the answer looks more organised.
I would give this method 6 out of 8 marks.
ReplyDeleteStrengths:
- Measurements that were made were clearly stated.
- Equipment used have also been mentioned.
- The method has been written in a logical and organised sequence with all the relevant information, with good grammar and spelling.
Improvements:
- The risk assessment should be written in a separate table to ensure the answer is well structured and also add more for the risk assessment.
- State the control variables and how you are going control them.
- If possible explain answers with more detail and specialist terms.
It is out of nine, so you are giving her a 6.75 which is a bit harsh.
DeleteI give your answer a 6/9.
DeleteStrengths:
Method will lead to valid results.
You have written down specific amounts.
You have your risk assessment.
Improvements:
You haven't said how you will measure it and what equipment you will use to measure it.
You need to state the control variables as well as structuring your answer better.
I would give this method 6 out of 8 marks.
ReplyDeleteStrengths:
- The hypothesis is concise and relates to the overall method for the investigation.
-All measurements and symbols are shown in a manner which makes it easy to understand.
- The logical pattern of the method makes the method simple to perform.
Improvements:
- Use the "Risk, Hazard, Precaution" template for your risk assessment. This will make the risk assessment easy to understand.
- The method and risk assessment should be individualized. If you had provided the websites in the "research sources" category, it may be better to relate to that. You may also choose to include risk assessments on the category in the CRN.
I would give this method probably 6 out of 9.
ReplyDeleteStrengths:
The method is written out step by step using numbers to indicate what order each step is done in.
Mentions all the key parts to the question, which are: equipment, method, variables and risk assessment. Even if some are done faintly.
The measurement that will be made is stated clearly.
Improvements:
To improve the QWC use subheadings to organise the work so that different sections can be easily identified.
Even though two control variables have been stated indirectly, to gain top marks you should expand on them in a separate paragraph. This should include information on how these variables will be controlled.
Use specialist terms, such as control variable.
Should also list the equipment so that it is easier to find, instead of just stating it within the method.
I would give a 7 out of 9
ReplyDeleteStrengths:
Organised
Explanations to certain steps included.
Said you would do repeats to enable valid results
Improvements:
Split your method into different parts using numbers for a separate step rather than commas in the same step.
Give exact units as on step 5, you said 'full of water'.
I would give 6 out of 9 for this method:
ReplyDeleteStrengths :
The method will enable valid results to be collected and is related to the hypothesis. The method is also logically sequenced
Most of the equipment needed has been mentioned and so have the measurements needed.
Improvements:
The hypothesis is not really clear
The risk assesment should be separate from the method to make your answer more clear
Also the variables need to be identified separately and you could use specialist terms
I would give this answer 6/9 marks.
ReplyDeleteWWW:
• The method is clearly represented using numbers to show the different steps.
• The method will enable valid results to be collected.
• The equipment needed is stated.
• A few risks of this experiment are also given.
EBI:
• It is confusing as you do not know which equipment you need until you read the method.
• The structure of the answer is not very clear as everything is written in one section.
• The significant control variables are not outlined in a separate section.
• The risk assessment is not properly assessed as it does not identify the hazards, risks, and precautions.