** 2013 Biology HL Before/After **

Scuid Mhór

SecondMan wrote: »

Mid exam? How?

It was an emergency :cool:

Overall it was a tough representation of the biology course. The paper seemed a lot worse at the start though. As I worked through it, it got better.

weirdspider

Slow Show wrote: »

Would anyone mind running through the part c of genetics briefly? What's the function of spindle fibres? Think I got it right but not sure. Also y'know for the nucleus at metaphase, how many double-stranded chromosomes should there have been, six or three? I vaguely remember my teacher saying both were acceptable but not sure, I did six first then crossed it out and did three (not sure how cancellation works in Section C, I know for one they accept it and don't give marks for cancellation) :L

Seriously SO annoyed there was no cross, it made genetics so much more annoying for me!

They contract at anaphase to separate the chromosomes.
I chose 6..That was one of the questions that threw me too

That paper, while managable in parts, was certainly one of the most difficult that I'd seen. Last year was probably too easy so they didn't want to have the too many As issue. Which in a way I suppose is fair

sganyfx

SecondMan wrote: »

Mid exam? How?

I complained to my supervisor, filled out a report and one of the members of staff went and phoned the exam board. The main problem is there is not two axis for that experiment, we have enzyme activity for the Y axis but what is the X axis? If you were to do a graph you would have needed the temperature or pH experiment. Provided you did the temperature graph and stated there is no enzyme activity in the denatured test tube, you should be fine I guess.

Monsieur Folie

SecondMan wrote: »

Mid exam? How?

You put up your hand, say "I think there's a problem with this question". A sound supervisor will then relay the information on and the school will sort it out. I saw it happen in that infamous Junior Cert business exam. :P

0mega

weirdspider wrote: »

They contract at anaphase to separate the chromosomes.
I chose 6..That was one of the questions that threw me too

That paper, while managable in parts, was certainly one of the most difficult that I'd seen. Last year was probably too easy so they didn't want to have the too many As issue. Which in a way I suppose is fair

6 was correct.

weirdspider

Glee_GG wrote: »

but there is no volume of froth produced because the enzymes denatured?!

Nope, there would be a certain level produced as there is oxygen in the hydrogen peroxide itself but also from experimental errors such as shaking the test tube froth could arise. I wouldn't have drawn a straight line practically on the X axis

woopah92

There was nothing wrong with the enzyme question lads. You just had to use your brain to work it out. Not that difficult at all.

Monsieur Folie

I put pH on the x-axis like an eejit, only realising now how temperature would have been more relevant since it was denaturisation. Very unfair question though, I was convinced it was a mistake and that either the graph Q wasn't meant to be there, or else it wasn't the denaturisation Q that we were supposed to be answering on..

Who_Knows

Whoops did the heat denaturisation one completely wrong. But I did the other two experiments so I think I still have a shot at an A1.

Overall, weird paper. Usually biology is really familiar and easy but every question seemed to want you to think things through. What did people say for 'How might the scientists have measured the amount of cigarette filter fibre in one nest?' That completely threw me, think I ended up saying with a weighing scales... Some really weird questions all around.

weirdspider

0mega wrote: »

6 was correct.

Thanks for telling me It seemed like an awful lot to give to draw, generally they only ask for 2/3 so I wasn't certain

Lucan Bohs

What is the source of heat for the dog and the lizard?

0mega

I feel another maths controversy stirring.. :pac:

weirdspider

woopah92 wrote: »

There was nothing wrong with the enzyme question lads. You just had to use your brain to work it out. Not that difficult at all.

That was essentially the basis of the entire exam. It really tested whether or not you understood the topics as opposed to your ability to learn off and that should fairly differentiate the A1 candidates from the rest.
(not arrogantly implying I think I got an A1 or anything FYI! Its too hard to tell)

0mega

Who_Knows wrote: »

Whoops did the heat denaturisation one completely wrong. But I did the other two experiments so I think I still have a shot at an A1.

Overall, weird paper. Usually biology is really familiar and easy but every question seemed to want you to think things through. What did people say for 'How might the scientists have measured the amount of cigarette filter fibre in one nest?' That completely threw me, think I ended up saying with a weighing scales... Some really weird questions all around.

The marking scheme for those kinda questions will probably just be 'any reasonable answer'.

sganyfx

Lucan Bohs wrote: »

What is the source of heat for the dog and the lizard?

Dog - It's metabolism as it is an endotherm
Lizard - It's environment as it is an exotherm.

sganyfx

woopah92 wrote: »

There was nothing wrong with the enzyme question lads. You just had to use your brain to work it out. Not that difficult at all.

Okay then what did you do for it?

weirdspider

sganyfx wrote: »

I complained to my supervisor, filled out a report and one of the members of staff went and phoned the exam board. The main problem is there is not two axis for that experiment, we have enzyme activity for the Y axis but what is the X axis? If you were to do a graph you would have needed the temperature or pH experiment. Provided you did the temperature graph and stated there is no enzyme activity in the denatured test tube, you should be fine I guess.

The Y axis is the level/volume of froth produced in cm3

Jade.

Felt fine during the exam that I would at least pass but now I don't know!

kevin12345

sganyfx wrote: »

Dog - It's metabolism as it is an endotherm
Lizard - It's environment as it is an exotherm.

Will I get ANY marks for saying Warm-blooded and cold-blooded? For the life of me I couldn't think of the words Endotherm and Ectotherm when I was in there.

hfallada

WTF was up with the short questions. They were weird compared to other years. I still prefer the type of papers pre 2012. They were easier to go through than this one today. I thought the enzyme one wasnt the way it is on the syllabus. They arent supposed to ask the results just the effects of it.

Plus the exam could do with more room on the pages if you have to write so much

weirdspider

I'm not going to lie, I feel quite relieved that we're all on the same boat. In the middle of the exam I was scared in case I was the only one who found it more difficult than other years!

woopah92

sganyfx wrote: »

Okay then what did you do for it?

Time on the x-axis and volume of froth produced on the y-axis.
The boiled catalase line was just above the x axis and remained constant. The unboiled catalase line was rising and eventually levelled off.

weirdspider

hfallada wrote: »

WTF was up with the short questions. They were weird compared to other years. I still prefer the type of papers pre 2012. They were easier to go through than this one today. I thought the enzyme one wasnt the way it is on the syllabus. They arent supposed to ask the results just the effects of it.

Plus the exam could do with more room on the pages if you have to write so much

THIS! They only provide a single line for a definition that should take up 2/3 lines! So very very frustrating!

SecondMan

Who_Knows wrote: »

Whoops did the heat denaturisation one completely wrong. But I did the other two experiments so I think I still have a shot at an A1.

Overall, weird paper. Usually biology is really familiar and easy but every question seemed to want you to think things through. What did people say for 'How might the scientists have measured the amount of cigarette filter fibre in one nest?' That completely threw me, think I ended up saying with a weighing scales... Some really weird questions all around.

I said: "Take two samples of cigarette filters. Measure the amount of fibre of each and divide by 2 to get the average. Then count all of the cigarettes in the nest and multiply the amount by the average.

0mega

That paper was like the project maths of Biology to be honest!

weirdspider

kevin12345 wrote: »

Will I get ANY marks for saying Warm-blooded and cold-blooded? For the life of me I couldn't think of the words Endotherm and Ectotherm when I was in there.

Well thats a casual way of putting it I suppose, those terms aren't scientific terms. But hey, by the looks of things I'd say any decent enough answer like yours should be accepted

weirdspider

SecondMan wrote: »

I said: "Take two samples of cigarette filters. Measure the amount of fibre of each and divide by 2 to get the average. Then count all of the cigarettes in the nest and multiply the amount by the average.

Ohh I said take a nest, weigh it, let the birds add the cigarette filters then reweigh the nest.

200c200c

kevin12345 wrote: »

Will I get ANY marks for saying Warm-blooded and cold-blooded? For the life of me I couldn't think of the words Endotherm and Ectotherm when I was in there.

I wrote that too :L I hadnt a clue just gave it a guess :L

peekachoo

After reading this I'm so happy the enzyme experiment was the one I left out :pac:

sganyfx

kevin12345 wrote: »

Will I get ANY marks for saying Warm-blooded and cold-blooded? For the life of me I couldn't think of the words Endotherm and Ectotherm when I was in there.

Endotherm and Exotherm are kinda the new words for those two, so in my opinion you should.