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Biology HL Paper 3


AnjaDe

Options (Section B)  

60 members have voted

  1. 1. Which option did you take?

    • A
      11
    • B
      2
    • C
      11
    • D
      36


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I did Option A but I found the Section A to be full of crap. Like I did not expect the plant questions at all so I have this moment of internal screaming at the exam room:lc:

What did you guys answer for the possible reason why the young shoots might have a higher rooting rate than mature shoots? I wrote that a possibility would be a higher auxin concentration in younger shoots compared to older shoots. 

In addition to that, I think there's also another question where you to evaluate the claim that humans have the biggest brain to body mass ratio right? what did you guys answer for that?

I studied a lot of brain parts for Option A but none of it came out :/. 

 

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11 minutes ago, ShootingStar16 said:

The tissue I labelled xylem and I just winged one of the q's on it. Also for another question, I just put that it's because aphids feed off sap :P 

 

Overall, I don't think I did too well on it but it could have been worse. I did recognize a lot of stuff and was able to at least somewhat answer the questions (I got the one about the coral because I did go over that and Section B for me was ok) though but thing is I did not realize the aphids thing would be on paper 3 because I thought it was paper 2 content :P 

 

For the coral question, what did you write for the possible effect on increasing carbon dioxide concentration that decreases the calcium concentration on the corals?

I wrote about possible bleaching of the corals and the weakening of the strength of the corals which may lead to damage.

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2 minutes ago, #teamnosleep said:

For the coral question, what did you write for the possible effect on increasing carbon dioxide concentration that decreases the calcium concentration on the corals?

I wrote about possible bleaching of the corals and the weakening of the strength of the corals which may lead to damage.

I talked about how the increased carbon dioxide concentration dissolves in water forming carbonic acid which becomes hydrogen carbonate ions reducing carbonate ion concentration, so corals can't deposit calcium carbonate into their bodies. 

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2 hours ago, ShootingStar16 said:

I talked about how the increased carbon dioxide concentration dissolves in water forming carbonic acid which becomes hydrogen carbonate ions reducing carbonate ion concentration, so corals can't deposit calcium carbonate into their bodies. 

Didn't think about that argh :?. You seem to be a very smart Bio student. 

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4 hours ago, Michael21 said:

I thought c 14 radioactive labeling is a different method for observing solute flow? Aphid stylets is one method which it was asking , didn't think it was relevant to mention the other? 

no they are the same thing. you cannot measure the movement of sap merely using the aphid stylets. It is the combination of radioactive labelling + autoradiography and stylets that allow us to measure the movement.

 

See: https://www.youtube.com/watch?v=gyQNXLagSJk&index=10&list=PLU9wEyzVsaZWv8thWtol13z6MEoQIf8EZ

 

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15 hours ago, David GW said:

I did option D and I honestly think (including section A) it was a really easy exam, probably my best paper out of the three.

The aphid is an insect which injects its stylet into the phloem and sucks the sap, so if the aphid is removed from its stylet a sample containing phloem sap can be obtained and analysed. I can't remember the exact answers I wrote down, only that on the diagram you had to write xylem. 

YEEEEES!! this paper was probably the best paper ever written. I mean paper 1 and 2 were just terrible but paper 3 in my opinion was really straight forward. I did option D and was really surprised that they used some questions which were in the specimen paper.

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16 minutes ago, Kristina Rollová said:

YEEEEES!! this paper was probably the best paper ever written. I mean paper 1 and 2 were just terrible but paper 3 in my opinion was really straight forward. I did option D and was really surprised that they used some questions which were in the specimen paper.

really? I think paper 1 was fine. Some questions were just funny.  Paper2 was bad.. :( Paper 3 was the worst. 

 

I really don't know how to deal with like data based questions.... bye 7, bye uni.. haha

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20 hours ago, inriya said:

Worst of the worst. I did not expect to be so many plants related question in the core part. 

However, I did option D and not finding it to be extremely difficult, it is related somehow. I had actually studied for Liver and PKU before the exam, and I was so glad that it came on.

Wait haha there was a question on PKU? I don't recall that lel

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1 hour ago, ultimateone said:

Wait haha there was a question on PKU? I don't recall that lel

Yea there was a question on the cause of PKU. Then there was a question on the regulation of ventilation using chemoreceptors, brestfeeding oxytocin and prolatate, liver, secondary messengers (peptide hormones) , and fibre and mean time of digestion, and on irregular heart beat... :D I think that the exam was really good as it covered a lot of the topics from the option, not like paper 1 and 2 which only focused on evolution and ecology.

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2 hours ago, Lovelife said:

really? I think paper 1 was fine. Some questions were just funny.  Paper2 was bad.. :( Paper 3 was the worst. 

 

I really don't know how to deal with like data based questions.... bye 7, bye uni.. haha

Let's hope that they put the boundaries down :/ I think Biology exams were still at least a bit better than physics as all the people who took physics wanted to leave during the exam as they couldn't answer a single question. 

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Guest Anoushka Anand
18 hours ago, AnjaDe said:

Ah yes, that question about mother's milk and amino acids was a bit strange, did you relate it to PKU at all? Because I wrote how the only source of nutrients for a new-born baby is mothers milk, so if PKU can be diagnosed only a few days after birth, then it most come from mother's milk?

The answer to that question had to be written in relation to the table on the previous page that was comparing the amino acid content gotten from hen eggs, human milk and cow's milk.

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I found paper 3 ok as an examination, although at times it deviated from the initially set specimen papers present on the OCC that our teachers gave us. I believe that section A was ok, and that Option C was based around some of the most application-heavy sections of the syllabus. I have mainly head positive feedback on the paper, although some were upset with the aphid stylet questions in section A.

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