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WJEC A-Level Biology Unit 3 (A2) [7th June 2023] Exam Chat


WJEC A-Level Biology Unit 3 | 7th June 2023 [Exam Chat]

Welcome to the exam discussion thread for this exam. Introduce yourself! Let others know what you're aiming for in your exams, what you are struggling with in your revision or anything else.

Wishing you all the best of luck.

General Information
Date/Time: 7th June 2023 PM
Length: 2h

Link to Study Group:
A-Level Biology Study Group 2022-2023

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How did everyone find it?
Reply 2
Original post by Kahootchamp
How did everyone find it?

I think it went well!! Some weird questions like that domain one?? But on the whole it wasnt too bad! How did you find it?
Yeah I quite liked it as well. I was totally expecting an aseptic technique question or serial dilution for the 9 marker, but the question wasn’t bad. I can’t believe there was only two marks for microbiology… and what was that safe space for operation question?!?!
Reply 4
Original post by Kahootchamp
Yeah I quite liked it as well. I was totally expecting an aseptic technique question or serial dilution for the 9 marker, but the question wasn’t bad. I can’t believe there was only two marks for microbiology… and what was that safe space for operation question?!?!


same. i was also expecting the 9 marker to be on populations and sampling like measuring ecosystems but the one we got wasnt bad. i found it weird having to describe both images. i also found it funny how they used trucks in question 1.
Reply 5
Original post by Sheepwool
I think it went well!! Some weird questions like that domain one?? But on the whole it wasnt too bad! How did you find it?


what did you write for domain. i wrote eukaryotes and because it has a nucleas but im probably wrong.
Reply 6
Original post by Kahootchamp
Yeah I quite liked it as well. I was totally expecting an aseptic technique question or serial dilution for the 9 marker, but the question wasn’t bad. I can’t believe there was only two marks for microbiology… and what was that safe space for operation question?!?!


it was probably explaining how the boundries enable human activity to operate without risk of irreversable damage to earth.
Reply 7
Original post by hooleeaa
same. i was also expecting the 9 marker to be on populations and sampling like measuring ecosystems but the one we got wasnt bad. i found it weird having to describe both images. i also found it funny how they used trucks in question 1.


Really? If u look at the last 3 years of past papers you could’ve figured out the 9 marker would be nervous or respiration
Reply 8
Original post by hooleeaa
what did you write for domain. i wrote eukaryotes and because it has a nucleas but im probably wrong.


So did i, and membrane bound organelles, and its multicellular
Reply 9
Original post by Kahootchamp
How did everyone find it?


strange. i found the enzyme question in the beginging hard to remember, but i ended up writing nad and fad. there was a part that asked for you to describe why the yeild of atp is different and i think my answer was silly, but i talked about the how there is 10 nad molucules but only 2 fad produced. i worded it weirdly too. ugh
Reply 10
Original post by ZaheeT
Really? If u look at the last 3 years of past papers you could’ve figured out the 9 marker would be nervous or respiration

teachers at my school were about the ranking in the advanced info, the first two units in biology had 9 markers on the topic with the highest rank.
Reply 11
Original post by hooleeaa
strange. i found the enzyme question in the beginging hard to remember, but i ended up writing nad and fad. there was a part that asked for you to describe why the yeild of atp is different and i think my answer was silly, but i talked about the how there is 10 nad molucules but only 2 fad produced. i worded it weirdly too. ugh

I think for that one it is because in chemiosmisis there are 3 pumps for NAD which produce 3 ATP and 2 pump fot FAD which produce 2 ATP
Reply 12
I thought the paper was generous. I was expecting a lot worse seeing that Populations and Ecosystems were the highest on the advanced information.
Reply 13
Original post by Sheepwool
I think for that one it is because in chemiosmisis there are 3 pumps for NAD which produce 3 ATP and 2 pump fot FAD which produce 2 ATP

Yes, that is what I wrote as well. It's in my textbook somewhere :smile:
Reply 14
What did everyone write for the chemiosmosis question with the organelle and the pH?
Reply 15
Original post by Sheepwool
What did everyone write for the chemiosmosis question with the organelle and the pH?

I said something similar to this -

Chemiosmosis is the diffusion of protons from a region of higher concentration to a region of lower concentration, down an electrochemical gradient. Therefore, when the external solution is at the same pH as the membrane there is no movement of protons out of the membrane

However, when you increase the pH of the external solution to pH8 the concentration of protons in the external solution is lower than the pH of the membrane. Therefore, there is movement of protons down said gradient from the membrane to the external solution. Since ATP Synthetase is present in the stalked particle, it catalyses the phosphorylation of ADP and a phosphate to produce the ATP.
Reply 16
Original post by Sheepwool
What did everyone write for the chemiosmosis question with the organelle and the pH?


it was for photosynthesis and that was organelle chloroplasts i think. i might be getting mixed up with another question but i talked about how electrons being excited from light energy is carried to a series of carriers in thylakoid membrane, energy is released to pup protons from stroma to spaces between thylakoid. then i talked about chemiosmosis and how protons flow down electrochem gradient into strona through atp synthase. energy is released to synthesis atp. ill be mad if im wrong because what else could i have possibly said.
Reply 17
Original post by 048243
I said something similar to this -

Chemiosmosis is the diffusion of protons from a region of higher concentration to a region of lower concentration, down an electrochemical gradient. Therefore, when the external solution is at the same pH as the membrane there is no movement of protons out of the membrane

However, when you increase the pH of the external solution to pH8 the concentration of protons in the external solution is lower than the pH of the membrane. Therefore, there is movement of protons down said gradient from the membrane to the external solution. Since ATP Synthetase is present in the stalked particle, it catalyses the phosphorylation of ADP and a phosphate to produce the ATP.


i said something very similar but less detailed. i said when ph rises, the protons flow down the electrochemical gradient, through atp synthase, into stroma or whatever i mentioned. energy releases is used to synthesis ATP from adp and pi
Reply 18
Original post by hooleeaa
i said something very similar but less detailed. i said when ph rises, the protons flow down the electrochemical gradient, through atp synthase, into stroma or whatever i mentioned. energy releases is used to synthesis ATP from adp and pi

There was a small question asking about the marking used on frogs. They mentioned cutting off a toe or something. How did you say that it may affect the validity of the results?
(edited 8 months ago)
Reply 19
Original post by 048243
I said something similar to this -

Chemiosmosis is the diffusion of protons from a region of higher concentration to a region of lower concentration, down an electrochemical gradient. Therefore, when the external solution is at the same pH as the membrane there is no movement of protons out of the membrane

However, when you increase the pH of the external solution to pH8 the concentration of protons in the external solution is lower than the pH of the membrane. Therefore, there is movement of protons down said gradient from the membrane to the external solution. Since ATP Synthetase is present in the stalked particle, it catalyses the phosphorylation of ADP and a phosphate to produce the ATP.

Wait did they purposely increase the pH? I thought it happened naturally over a short amount of time.
(edited 8 months ago)

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