Edexcel 6BIO1 ~ 21th May 2013 ~ AS Biology

Hey guys hows everyone feeling about this exam?
Can someone answer the following questions for me, struggling a bit on the topic of tissue fluid. :colondollar:

Explain how the structure of a capillary is related to the formation of tissue fluid? (3)

Suggest why proteins are present in the plasma but are not normally present in tissue fluid (2)

Tissue fluid is reabsorbed back into capillaries as a result of the osmotic effect of the plasma proteins. Suggest why this reabsorption is reduced in a person on a protein deficient diet.(2)

1) - capillaries walls are single-cell thick and have small gaps between cells, so fluids can easily diffuse out
- due to hydrostatic pressure
- leading to formation of tissue fluid that bathes the surrounding cells. (?)
2) - proteins are present in plasma due to exocytosis from others cells in the blood
- however they are too big (and insoluble) to simply diffuse through the capillary walls, so large proteins are not found in tissue fluid.
3) - a person on this diet will have relatively low protein concentration in the plasma
- therefore the concentration gradient between plasma and tissue fluid is less
- rate of osmosis reduces and less reabsorption of water take place.

Reply 21

Bridget Jones

19

are you guys doing the "normal" Edexcel or Edexcel SNAB?

Reply 22

claimstudent

Original post by Relaxedexams

This thread is for the upcoming Biology unit 1 exam. Discuss/ask questions/answer questions and clear doubts here :smile:

its C.

Reply 23

claimstudent

Original post by Relaxedexams

The only thing I'm sure of is that the primary structure will be altered, so it cannot be D for sure.

Where is this question from? :0

its c because primary str. determines da secondary and tertiary str. but am not sure if quaternary str. is also affected or not

Reply 24

SKK94

1

Original post by Jeniffer05

Does anyone have the jan 2013 paper for unit 1?

You can get it from here :smile:

https://www.xtremepapers.com/community/threads/edexcel-january-2013-question-papers-all-gce.23183/

Reply 25

examss

can anyone help me with biology revision guide book for AS level?
Or where i can get the soft copy from?

Reply 26

CHEM AND BIO TIME!

13

going all out for this test..

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Reply 27

claimstudent

go to freeexampapers.com, im sure ull get everything over there!!!!

Reply 28

examss

i couldn't get it.. can you please help me find it?

Reply 29

Relaxedexams

OP

2

Original post by nivvy21

are you guys doing the "normal" Edexcel or Edexcel SNAB?

Normal Edexcel I believe (GCE from 2008)

Reply 30

newyork newyork

3

can someone help me with this question. during the cardiac cycle the pressure in the left ventricle falls to a much lower level than in the aorta. Suggest an explanation for this difference.

Reply 31

Kurraiyo

7

Original post by newyork newyork

can someone help me with this question. during the cardiac cycle the pressure in the left ventricle falls to a much lower level than in the aorta. Suggest an explanation for this difference.

After ventricular systole, the pressure in the ventricle falls because the muscles are no longer contracted. This means that the semi-lunar valves at the opening of the aorta will shut, preventing backflow of blood from the aorta into the ventricle. Due to the elasticity of the aorta it stretches then recoils and maintain a high blood pressure, but the left ventricle has a period of rest (diastole) when it is being refilled, and the pressure falls. :smile:

(edited 10 years ago)

Reply 32

jojo1616

Bio unit 1 is approaching, nervous, what's the best to revise on the day b4 exam? Past paper or textbook?

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Reply 33

Sravya

Original post by jojo1616

Bio unit 1 is approaching, nervous, what's the best to revise on the day b4 exam? Past paper or textbook?

Posted from TSR Mobile

I would suggest past paper the day before just to see f you have any last minute weak areas. Also I would do it in complete exam condition. With no distractions no looking at the markscheme till the very end. And the morning of the exam just go through all your notes so you get a quick summary of everything...

This is my 3rd time doing it..I have always been 1 mark of an A it is ridiculous!

Reply 34

NilFBosh

3

Original post by jojo1616

Bio unit 1 is approaching, nervous, what's the best to revise on the day b4 exam? Past paper or textbook?

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I recommend to finish all ur pastpapers now and read the revision guide a day b4 the test

Reply 35

jojo1616

Original post by NilFBosh

I recommend to finish all ur pastpapers now and read the revision guide a day b4 the test

Yup, thinking of doing that too, I'm going to finish past papers(new syllabus) by today hopefully and revise again unit 1 tomorrow

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Reply 36

jojo1616

Original post by Sravya

I would suggest past paper the day before just to see f you have any last minute weak areas. Also I would do it in complete exam condition. With no distractions no looking at the markscheme till the very end. And the morning of the exam just go through all your notes so you get a quick summary of everything...

This is my 3rd time doing it..I have always been 1 mark of an A it is ridiculous!

Yup, I think my weak area is that I don't have a good memory to rmb all the stuffs ! TT anyway, good luck to u
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Reply 37

Tha Realest

10

In regards to the 6BIO1 June 2009 paper...

Can someone please provide me a link from google images to question 1(bi) , because there as so many different versions of the diagram ; I am not really sure which would get the : 3 marks.

Thanks

Reply 38

Lost_Life

Original post by Tha Realest

In regards to the 6BIO1 June 2009 paper...

Can someone please provide me a link from google images to question 1(bi) , because there as so many different versions of the diagram ; I am not really sure which would get the : 3 marks.

Thanks

you draw the 2 nucleotides given from the question..