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Biology Paper 1 & 2 HL


kyriakosr21

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I agree, these were really hard papers! Some of the p1 questions were tricky and section A in p2 was also unusual. Section B I found rather easy, I chose 5 and 7 question, because I didn't feel comfortable with nephron.  

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The paper 1 was slightly more difficult than previous years (it required more thinking, in my opinion), but I thought that the paper 2 was fine. Considering the difficulty of the specimen papers, I think these two were not too easy, but not too difficult either.

Edited by isaiguana
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I did the TZ0 papers and I didnt understand the data response questions...if ur in the same timezone as I am they were about embryonic stem cells and umbilicalcord stem cells. The question about the evaluation of the effectiveness of stem cells in treating type 1 diabetes was soooo confusing...unbilical cord stem cells arent embryonic stem cells right?😂😂

also, question 5a was totally confusing--the activity of enzymes. I wrote about enzymes lowering the activation energy and talked about some other stuff, but my friends talked about the induced fit model and lock and key hypothesis. 

Anyways, hoping for a lower boundary:((

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2 minutes ago, =-= said:

I did the TZ0 papers and I didnt understand the data response questions...if ur in the same timezone as I am they were about embryonic stem cells and umbilicalcord stem cells. The question about the evaluation of the effectiveness of stem cells in treating type 1 diabetes was soooo confusing...unbilical cord stem cells arent embryonic stem cells right?😂😂

also, question 5a was totally confusing--the activity of enzymes. I wrote about enzymes lowering the activation energy and talked about some other stuff, but my friends talked about the induced fit model and lock and key hypothesis. 

Anyways, hoping for a lower boundary:((

I also wrote the TZ0 paper. I think that the question you are referring to was meant to have you evaluate simply the effectiveness of embryonic stem cells, and possibly compare this to that of the umbilical cord stem cells. That's how I interpreted it, anyway.

I also answered 5a. I discussed the definition of an enzyme and how the active site works, mainly.

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I don't really know what happed but it looks like we all have the same timezone TZ0 O.o Yeah i also mentioned induced fit model at some point as it shows specifity of an enzyme.. We are all hoping for low boundaries because for most people those papers were relatively though

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Paper 1 and 2 are not hard, but I wasn't ready at all. Like i thought there would be more questions about the nature of science or applications and stuff. Section B was really normal... 

 

However, again, I didn't study for bio. I just think the papers were ok.  (at least I could answer all of them)

 

P.S people who made the specimen paper had some problems. The actual paper and the specimen paper were totally different !!!! Like totally 

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In section B, there was question 7 (c) marked for 8 points, with the message sth like this: "In hot temperatures the rate of transpiration in plants is very high. Outline the structures and proccesses that allow the water to be replaced". Can somebody recall the exact content of the question? What have you written there? Together with class mates we had the argue, whether we should write there everything from absorption water, move of water in the xylem, structure of xylem, cohesion-adhesion and so on, or we should write about adaptations of xerophytes? Since they asked about water REPLACEMENT, I suppose we had to write everything about the structure of xylem and movement of water, but I'm not sure. What do you think guys?

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2 minutes ago, matigora said:

In section B, there was question 7 (c) marked for 8 points, with the message sth like this: "In hot temperatures the rate of transpiration in plants is very high. Outline the structures and proccesses that allow the water to be replaced". Can somebody recall the exact content of the question? What have you written there? Together with class mates we had the argue, whether we should write there everything from absorption water, move of water in the xylem, structure of xylem, cohesion-adhesion and so on, or we should write about adaptations of xerophytes? Since they asked about water REPLACEMENT, I suppose we had to write everything about the structure of xylem and movement of water, but I'm not sure. What do you think guys?

I wrote about the process of transpiration, so basically the absorption of water, xylem, co-hesion adhesion and all that. I don't think they meant the adaptations of the xerophytes, or at least that's how I interpreted it. 

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Paper 1 and 2 were fine for me. There were 8 at first that I couldn't answer in Paper 1, but I went back and came to a reasonable answer for 5 of them. Nature of Science questions threw me off, because we never studied that. For Paper 2, I chose to do #5 and #6 in Section B, and it paid off that I did past papers! A lot of people didn't choose #5 because they thought Prokaryotic replication was different from Eukaryotic, but it's pretty much (if not exactly) the same, from what I remember. I'm glad I didn't get stuck with #7, because Plant Biology is my worst topic...

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I thought they were both easy. Paper 1 got me stumped a little just because I didn't review ecology and evolution as much. The questions in paper 2 about methane and water were also a little weird because I didn't review that as much as I should've. But over all it wasn't that bad

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Hello,

I thought both of them were reasonable though I did have some difficulty with Section A for Paper 2. What did you write on the question that had you explain the difference between Group 1 and Group 2 in study 2 (the difference in C-peptide levels) (stem cell study)?

Also, for the water loss question and replacement of this water, question 7, I talked about the transpiration pull and the structure of xylum (drew the cross-section of stem(dicot) and root showing xylum and phloem). I also explained some adaptions that allowed for more water intake such as hairy and deep roots. I also talked about the active ion movement into the roots so the water moves into the roots by osmosis to balance the gradient.
For safety measure, I also added a few xerophyte adaptions. :P

Edited by Sarthak Garg
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25 minutes ago, Sarthak Garg said:

Hello,

I thought both of them were reasonable though I did have some difficulty with Section A for Paper 2. What did you write on the question that had you explain the difference between Group 1 and Group 2 in study 2 (the difference in C-peptide levels) (stem cell study)?

Also, for the water loss question and replacement of this water, question 7, I talked about the transpiration pull and the structure of xylum (drew the cross-section of stem(dicot) and root showing xylum and phloem). I also explained some adaptions that allowed for more water intake such as hairy and deep roots. I also talked about the active ion movement into the roots so the water moves into the roots by osmosis to balance the gradient.
For safety measure, I also added a few xerophyte adaptions. :P

C-peptide is produced at high level when insulin is not required in experiment 2 because of injection. It shows a high level because the group 1 DOES NOT NEED INSULIN.  That experiment does not reflect that group 1 has an effective beta cells, but it reflects how much c-peptide is cut to produce insulin. In this case, experiment 2 group 1 does not require any insulin judging from the high level. 

However in the experiment 3 when they inject adult stem cell, a high c-peptide level will reflect the effectiveness of beta cells because they are not injecting any extra c-peptide into it . 

For the last question 1 j when they ask about effectiveness of embryonic stem cells, I said no because it requires consistent injection to produce enough insulin to lower glucose level. Adult stem cells are more ethical and requires only 1 injection to produce more c-peptide for proinsulin to cut on , it is specialized therefore maybe more effective. 

 

And there you go, Question 1. 

Paper 1 and 2 isn't hard at all. Especially Paper 2 when you did a lot of past papers, it is fine than asking you about the outcomes of Human Genome Project, yikes. 

How much time did each of you use in Paper 2? I used only 1 hour and 30 minutes then went to sleep. 

Edited by inriya
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58 minutes ago, inriya said:

C-peptide is produced at high level when insulin is not required in experiment 2 because of injection. It shows a high level because the group 1 DOES NOT NEED INSULIN.  That experiment does not reflect that group 1 has an effective beta cells, but it reflects how much c-peptide is cut to produce insulin. In this case, experiment 2 group 1 does not require any insulin judging from the high level. 

However in the experiment 3 when they inject adult stem cell, a high c-peptide level will reflect the effectiveness of beta cells because they are not injecting any extra c-peptide into it . 

For the last question 1 j when they ask about effectiveness of embryonic stem cells, I said no because it requires consistent injection to produce enough insulin to lower glucose level. Adult stem cells are more ethical and requires only 1 injection to produce more c-peptide for proinsulin to cut on , it is specialized therefore maybe more effective. 

 

And there you go, Question 1. 

Paper 1 and 2 isn't hard at all. Especially Paper 2 when you did a lot of past papers, it is fine than asking you about the outcomes of Human Genome Project, yikes. 

How much time did each of you use in Paper 2? I used only 1 hour and 30 minutes then went to sleep. 

That's approximately what I ended up saying in the end but its good to know that someone else said the same things. I'd agree that the exams were pretty easy. Paper 1, I was done in 30 mins and so I just did the paper again and again to review it. Paper 2, I was done in 1:50. Then I just kept revising my answer. :P

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There was just a few crazy questions on the paper 1, like DNA tech one with all the strands. I had no idea how to do it. Also I dont remember the exact question in the paper one it was asking about CO2 in plants, I put RuBP but some people said Gp3Tp for that one. And for another paper 1 problem it was asking about what allows plants' stems and roots to grow, I was debating between auxin and meristem but ended up going with meristem. As for the paper 2, the section b was okay, and the section a was rather confusing at times but not that hard. Paper 1 was def harder.

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19 minutes ago, mzamzam said:

There was just a few crazy questions on the paper 1, like DNA tech one with all the strands. I had no idea how to do it. Also I dont remember the exact question in the paper one it was asking about CO2 in plants, I put RuBP but some people said Gp3Tp for that one. And for another paper 1 problem it was asking about what allows plants' stems and roots to grow, I was debating between auxin and meristem but ended up going with meristem. As for the paper 2, the section b was okay, and the section a was rather confusing at times but not that hard. Paper 1 was def harder.

The radioactive isotope one? I put Glycerate-3-phosphate (or whatever it was), because it's the first carbon compound made (after RuBP combines with the radioactive CO2 and the unstable intermediate breaks down).  I also put meristem for the other question.

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6 hours ago, matigora said:

In section B, there was question 7 (c) marked for 8 points, with the message sth like this: "In hot temperatures the rate of transpiration in plants is very high. Outline the structures and proccesses that allow the water to be replaced". Can somebody recall the exact content of the question? What have you written there? Together with class mates we had the argue, whether we should write there everything from absorption water, move of water in the xylem, structure of xylem, cohesion-adhesion and so on, or we should write about adaptations of xerophytes? Since they asked about water REPLACEMENT, I suppose we had to write everything about the structure of xylem and movement of water, but I'm not sure. What do you think guys?

Hey!
I wrote about apoplastic and symplastic transport since it asked about replacement of water, but just to be safe I also wrote about suction and tension in the xylem which replaces water lost by mesophyll!

The paper was really weird though...

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3 hours ago, mzamzam said:

There was just a few crazy questions on the paper 1, like DNA tech one with all the strands. I had no idea how to do it. Also I dont remember the exact question in the paper one it was asking about CO2 in plants, I put RuBP but some people said Gp3Tp for that one. And for another paper 1 problem it was asking about what allows plants' stems and roots to grow, I was debating between auxin and meristem but ended up going with meristem. As for the paper 2, the section b was okay, and the section a was rather confusing at times but not that hard. Paper 1 was def harder.

DNA Profiling requires tandemly repeated DNA, so it is D because at the 1st and 7th (?) codons are the same. 

COin plants is GP, not RUBP because 3RUBP + 3CO2 = 6 GP (GP is the first product to come across with CO2, not RUBP, it is just reacting with it.) 

What allows the plant's stems and roots to grow? Meristem. Auxin inhibits growth of buds and something like that (yeah I am weak at plants) 

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