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AQA GCSE - Unit 3 (P3,B3,C3) New specification papers.

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Original post by Captain Anonymous
did you get the mygcsescience ones?


Yep, they were very helpful. I think over the next week I'm going to do all the past papers again and see if I pick up more marks than I did the first time. Practise makes perfect!
Original post by CD223
1) The substance contains calcium because calcium compounds burn with a brick red flame and lithium compounds burn with a crimson flame.

2) The blue precipitate of copper hydroxide has formed. This means the compound originally contained Copper ions.

3) Magnesium, Aluminium and Calcium all dissolve in sodium hydroxide to form white precipitates.

If the precipitate dissolves in excess NaOH then it contains Aluminium ions.

If it burns brick red in a flame test as well as producing a white precipitate in NaOH it contained Calcium ions.

The remaining substance contains magnesium ions.

4) To detect a sulfate ion dissolve the substance in dilute hydrochloric acid and add barium chloride. A white precipitate of barium sulfate forms if sulfate ions were present in the original compound.

5) Iodide ions are present. This is because when an iodine compound is dissolved in dilute nitric acid and silver nitrate solution is added, a yellow precipitate of silver iodide is formed.

6) When you add a dilute acid to a carbonate compound, the gas carbon dioxide is released. This can be detected by bubbling the emergent gas through limewater, turning it cloudy.

Is that what you were getting at?

Also, could anyone be so kind as to explain to me the details of how fusarium is fermented to produce mycoprotein? I just never know how much detail we're supposed to know of the process..


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Perfect answers :smile:
Original post by sneakbo2
Fusarium is a fungus that produces mycoprotein as it is grown in a fermenter. It is supplied with glucose and mineral ions as well as oxygen as fuel for the Fusarium to respire aerobically. The glucose is formed by using enzymes to digest maize starch.

Keeping bacteria away: Three things - Sterilise the fermenter with steam, Sterilise the glucose and mineral ions, filter the air supply.

Temperature maintenence: Jacket of cold water outside of the fermenter, Air bubbles. This is needed because the Fungus releases energy in respiration which could cause enzymes in the fermenter to denature; as well as this the enzymes may not work well because they are not at their optimum temperature.

That's it really :smile:


Do we really need to know specifics about the fermenter? As in the revision guide + spec it doesn't talk about specific features of a fermenter. (was that the old spec??)
Original post by tohaaaa
Do we really need to know specifics about the fermenter? As in the revision guide + spec it doesn't talk about specific features of a fermenter. (was that the old spec??)


I don't think we particularly need to know it in quite that much detail, we really just need an overview. However, if there is a 4 or 5 mark question on the production of quorn, it'd be useful to know those extra details. Therefore, I recommend you try learning them, but don't prioritise it over learning other biology content.


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Reply 1364
Hi guys! So, first B3 exam in 10 days ! :O Time flies!!
Are you all guys prepared?? :rolleyes:
Not fully yet, but I'd liked to think I will be Monday.

How about you?
Original post by Arshii
Hi guys! So, first B3 exam in 10 days ! :O Time flies!!
Are you all guys prepared?? :rolleyes:


It's scary how the time has flown! But I think Biology is the one I'm probably feeling the most confident about (out of the unit 3 exams.) I'm doing unit 2's too, where I'm probably best at C2.

Has anyone got any good last-minute tips for the exams? I still need to properly memorize some information that I can never seem to remember so I think today I'll go about doing that.

Also if you haven't already I recommend doing the old specification papers and just missing out the questions that are no longer in the unit. Then at the end take that amount of marks away and work out a percentage - it's really useful to get an idea of how marks are allocated and a lot of the stuff is still similar.
Can someone answer this question please

'The water in the xylem is under tension. Explain how the walls of the xylem are adapted to cope with this'

thanks :smile:
Urn not completely sure, but I think its smething to do with the fact that osmosis is inportant in plants. When plants take in water by osmoisis the plant vacuole sweels and presses the cytoplasm against the cell wall. The pressure builds up until no more water is able to enter the cell which makes the cell hard and rigid
Where did you get that question from? :smile:
Reply 1370
Original post by dandaman7771
Not fully yet, but I'd liked to think I will be Monday.

How about you?


Yeah same here.. On Monday I should be prepared - like all the final revision done... and then for the next 7 days or so I wil be doing LOADS AND LOADS of exam questions and all the resources that our school has given us til the exam.. :smile:

Original post by Dougieowner
It's scary how the time has flown! But I think Biology is the one I'm probably feeling the most confident about (out of the unit 3 exams.) I'm doing unit 2's too, where I'm probably best at C2.

Has anyone got any good last-minute tips for the exams? I still need to properly memorize some information that I can never seem to remember so I think today I'll go about doing that.

Also if you haven't already I recommend doing the old specification papers and just missing out the questions that are no longer in the unit. Then at the end take that amount of marks away and work out a percentage - it's really useful to get an idea of how marks are allocated and a lot of the stuff is still similar.


Same here! B3 is the one I'm feeling the most confident about too!
And for last minute revision tips I would highly recommend flashcards/index cards! They are literally amazing (get them for £1 from asda :P ) But, whilst also writing them you are actually recapping the stuff and are very easy to carry around with you too! Also, I'm continuously listening to podcasts which are very helpful too when you are just about to sleep :smile: Hope this helps x
Original post by Hazwaz7
Yep, they were very helpful. I think over the next week I'm going to do all the past papers again and see if I pick up more marks than I did the first time. Practise makes perfect!



i thought mygcsescience was just videos not past papers?? Or are you talking about the past papers on the aqa website?
Original post by KimSmith1234
Can someone answer this question please

'The water in the xylem is under tension. Explain how the walls of the xylem are adapted to cope with this'

thanks :smile:

I don't think there is anything on the spec (the new one at least) where you have to explain the adaptations of tissue?
Original post by KimSmith1234
i thought mygcsescience was just videos not past papers?? Or are you talking about the past papers on the aqa website?


As well as the videos, he made some practise papers which you could buy from his website. I think the deadline for ordering them has passed now though.
Original post by lolface32
I don't think there is anything on the spec (the new one at least) where you have to explain the adaptations of tissue?


Yes thats exactly what i was thought! It was a question that my teacher gave us as part of our revision, dont understand why she gave it when we dont need to know about it
Original post by Hazwaz7
As well as the videos, he made some practise papers which you could buy from his website. I think the deadline for ordering them has passed now though.


Oh yeah i just checked, the deadline was on thursday :frown: what were the 6 mark questions on from the papers please??
Original post by Captain Anonymous
Where did you get that question from? :smile:



My bio teacher made a list of questions for us to revise from, i dont think we need to know about that though :smile:
Original post by KimSmith1234
Oh yeah i just checked, the deadline was on thursday :frown: what were the 6 mark questions on from the papers please??


The chemistry one was about why the conditions of the haber process are such.

The physics one was about the process of using electromagnetism to switch a high-voltage circuit on using a low-voltage circuit.

The biology one was on evaluating mycoprotein compared to meat, using information given in the question :-)

(Sorry if I've been a bit vague, but I don't want to give you too much detail since people have paid for the questions.)
Where are the discussions going to take place for the seperate science exams, like for unit 2's. Because this is like th only live thread :P lol
Reply 1379
Original post by Captain Anonymous
Where are the discussions going to take place for the seperate science exams, like for unit 2's. Because this is like th only live thread :P lol


Someone could make one now?

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