The Student Room Group

AQA BIOL1 Biology Unit 1 Exam - 16th May 2011

Scroll to see replies

Original post by liviaaa
There's no blood through the intestine. I think the conc gradient is maintained by the Sodium Pottasium pump.


I know, but the glucose is moved in the blood. When the glucose is absorbed into the epithelial cells it diffuses into the blood. The lower the conc. in the blood, the greater the rate of diffusion.

Does anyone remember what the EXACT questions was? (or to the best of their knowledge)
Reply 1101
Original post by EffKayy
What was the wording on the 6mark. Epithelial lining? :frown: Got so confused.
URGHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH


I think it was epithelial cells?

I only mentioned

-Squamous epithelial cells - short diffusion pathway
-Many villi/microvilli - large surface area
-Carrier proteins (but didn't say in the membrane... :s-smilie:) for co transport of glucose
-Conc gradient maintained by sodium pottasium pump

I didn't think to talk about the other organelles.. such as mitochondria :/ I'm guessing I'll only get about 3/6 for this.
Original post by ??????????????????
Everyone I talked to got like 1.17.
I think. Can't remember. Anyone can comfirm? It was the air exhaled/time?


Yeah I also got 1.17 but a friend of mine who is really good at maths got 1.4. So I'm a little confused. What did you get for the beats per minute question I got 100 beats per minute.
Reply 1103
Original post by Benevolence
I know, but the glucose is moved in the blood. When the glucose is absorbed into the epithelial cells it diffuses into the blood. The lower the conc. in the blood, the greater the rate of diffusion.

Does anyone remember what the EXACT questions was? (or to the best of their knowledge)


Oh I see what you mean yeah that's probably right :smile:
Reply 1104
Original post by Wick3d

Original post by Wick3d
Hmm, depends on the mark scheme but I'm gonna guess and say 4 marks. :tongue:

I put 0.6 and 0.7 for when the valves were closed.


i wrote the same 0.6 and 0.7 because the pressure in the ventricles stayed the same so i assumed the av valves were closed as the artiums was getting filled dont think its right
Original post by Limitless
I did the same did you get 1.17 second or did you get something like 1.4 seconds.

What did you get for the beats per minute question I got 100bpm.


i got 1.4 and i did 60/0.7 for beats per min which gave 85.7, one cardiac cycle (one heartbeat) took 0.7 seconds then you work how many of those 0.7 second beats occur in one minute( 60 seconds)...... i think
Original post by Benevolence
I know, but the glucose is moved in the blood. When the glucose is absorbed into the epithelial cells it diffuses into the blood. The lower the conc. in the blood, the greater the rate of diffusion.

Does anyone remember what the EXACT questions was? (or to the best of their knowledge)




HEY I WROTE THIS! Please say I can still pick up SOME marks?
NT book about villi

*increase surface area for diffusion
thin wall - reduce diffusion distance
move - mantain diffusion gradient
supplied with blood vessels so that blood can carry away absorbed molecules

that's all I wrote. - all wrong? I guess
Reply 1108
I'm pretty sure it was 85.7 rather than 100.

We were given values e.g.:
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7

As the values for 0.0 and 0.7 were the same I think people are confused as if the cycle lasted 0.6 or 0.7 seconds. If you plotted the movement off the graph, and worked out the beats per minute, you would take the points on the graph that were the SAME (not the point just before), therefore you use 0.7 value. I hope that makes sense..
Original post by HaimishaParekh
HEY I WROTE THIS! Please say I can still pick up SOME marks?


Yes of course :smile: That is a valid point. Do you remember the exact phrasing of the question by any chance?

For the other calculation - it was 1.4

What did you get for the heart? I put 87
I got 1.4 as it was somink like 6.5 to 2.3 and that took 3 seconds. so 4.2/3=1.4 ??
Then i got 85.7bpm as one cardiac cycle took 0.7 so did 60/0.7=85.7 ??
Then the emphysema i didnt write about elastin, but put stuff about reduced SA=less diffusion, cant exhale as much=lower concentration gradient, and longer diffusion pathway because of scar tissue (not sure if thats right?).
Original post by liviaaa
I'm pretty sure it was 85.7 rather than 100.

We were given values e.g.:
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7

As the values for 0.0 and 0.7 were the same I think people are confused as if the cycle lasted 0.6 or 0.7 seconds. If you plotted the movement off the graph, and worked out the beats per minute, you would take the points on the graph that were the SAME (not the point just before), therefore you use 0.7 value. I hope that makes sense..


If you thought one cycle lasted 0.6 seconds you got 100bpm.
If you thought one cycle lasted 0.7 seconds you got 85.7bpm.

Well at least thats what I think happened.
Original post by EffKayy

Original post by EffKayy
What was the wording on the 6mark. Epithelial lining? :frown: Got so confused.
URGHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH


It was so vague, I had no idea what they wanted so I wrote loads of random things:

-Villi/microvilli for large SA
-Thin cells, for short diffusion distance.
- Sodium pump to actively transport sodium into blood to establish concentration gradient, so glucose can move into cells with sodium via cotransporter.
- Membrane has co transporters and carrier proteins to speed up process.
- Membrane bound enzymes to hydrolyse substances, e.g maltose so that they are small enough.
- Lots of mitochondria as they release energy which is needed for active transport.
Doss exam, all that worry for nothing!
...1.4dms ....86bpm....easy question here, easy question there...blah blah 6 MARKS FOR EPITHELIAL CELLS? Yes please!

BRING THE HATE.

NB: Grade boundries are going to be sky high.
(edited 12 years ago)
Reply 1114
Original post by archie0705
I got 1.4 as it was somink like 6.5 to 2.3 and that took 3 seconds. so 4.2/3=1.4 ??
Then i got 85.7bpm as one cardiac cycle took 0.7 so did 60/0.7=85.7 ??
Then the emphysema i didnt write about elastin, but put stuff about reduced SA=less diffusion, cant exhale as much=lower concentration gradient, and longer diffusion pathway because of scar tissue (not sure if thats right?).


Empysema mark scheme from Jan said:

-Alveoli break down
-Walls thicken
-Less surface area
-Loss of elastin
-Alveoli can't recoil as reducded elasticity
Original post by Benevolence
Yes of course :smile: That is a valid point. Do you remember the exact phrasing of the question by any chance?

For the other calculation - it was 1.4

What did you get for the heart? I put 87


Oh thank god. I just hope it's not on the 'neutral' side of the mark scheme..
Unfortunately, i don't remember the exact phrasing, sorry!

Ahhh, I put 85. It was a question i left till last (i don't know why) so it literally a guesstimate.
Reply 1116
Original post by Limitless
If you thought one cycle lasted 0.6 seconds you got 100bpm.
If you thought one cycle lasted 0.7 seconds you got 85.7bpm.

Well at least thats what I think happened.


Yup it is :smile:
Original post by Benevolence
I know, but the glucose is moved in the blood. When the glucose is absorbed into the epithelial cells it diffuses into the blood. The lower the conc. in the blood, the greater the rate of diffusion.

Does anyone remember what the EXACT questions was? (or to the best of their knowledge)


it was: how are epithelial cells in the small intestine adapted to their role in the absorption of glucose?
Yeah. I think, as correctly stated by other people, it would be best to not stress about it. Just trust that you will get the mark that you deserve :smile: If you put the effort and the revision in, throughout the paper, it will show :smile:

If you didn't do too much revision, or maybe you did and still thought it went horribly, you can always do a lot better in the next exam. From what I have gathered, the majority of people found it a bit odd. People in my college were saying it was easy, as I generally thought it was. However, when I glanced across during the exam (as you do) I noticed she had quite a few things wrong.

Other people doing badly will improve your mark. Also the mark scheme is developed from paper to paper, depending on how the candidates generally answer. The reason for this is that AQA have been in some ways notorious for asking ambiguous questions on occasion.

So it's all good :smile:
Original post by EffKayy

Original post by EffKayy
NT book about villi

*increase surface area for diffusion
thin wall - reduce diffusion distance
move - mantain diffusion gradient
supplied with blood vessels so that blood can carry away absorbed molecules

that's all I wrote. - all wrong? I guess


That's not wrong at all, I don't think. The blood vessels point is good. The only thing is that none are specific to glucose. That's why the question was weird.

Quick Reply