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A level Biology: Post your doubts here!

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At the same time, blood at higher pressure from the left atrium can also enter the right atrium and I guess it will have a greater chance of flowing this way bqz movement is from high to low pressure
This will increase the pressure in the right atrium
Why is this so confusing :(
Maybe this time i get it well look when blood flow into the left atrium from the lungs it is not in high pressure so if blood do enter into the right atrium it won't affect that much am I right?
 
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because of the continuous mixing of blood, there will not be a significant change in the pressure on either side of the septum. the pressure might rise of fall a little depending on the movement of blood. e.g when left atrium contracts some blood is pushed to the right and then when the right atrium contracts some amount of blood will move to the left side, thus one can conclude that the most significant affect on the circulation is that there will be reduced oxygen saturation as the concentration gradient has been disturbed.
 
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because of the continuous mixing of blood, there will not be a significant change in the pressure on either side of the septum. the pressure might rise of fall a little depending on the movement of blood. e.g when left atrium contracts some blood is pushed to the right and then when the right atrium contracts some amount of blood will move to the left side, thus one can conclude that the most significant affect on the circulation is that there will be reduced oxygen saturation as the concentration gradient has been disturbed.
I might as well be wrong in my explanation. :'D It's been a long time since i last studied abt the heart.
 
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Guess what guys!,I found a question which is basically the same thing but with different wordings lul in 2014 paper. Btw I have memorized the question 30 to be either both 4 or both 4 and 5 cause it comes in every paper xD
upload_2018-5-30_6-54-4.png
 
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Guess what guys!,I found a question which is basically the same thing but with different wordings lul in 2014 paper. Btw I have memorized the question 30 to be either both 4 or both 4 and 5 cause it comes in every paper xD
View attachment 63719
Why have u memorized it?
Sometimes the question has slightly different wording...like it asks about the number of phospholipid layers, no. of phospholipid bilayers, etc
 
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Guess what guys!,I found a question which is basically the same thing but with different wordings lul in 2014 paper. Btw I have memorized the question 30 to be either both 4 or both 4 and 5 cause it comes in every paper xD
View attachment 63719
Why have u memorized it?
Sometimes the question has slightly different wording...like it asks about the number of phospholipid layers, no. of phospholipid bilayers, etc
Infact, it'll be a little more satisfying to draw and count than to recall : )
 
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How to do that? An example would be very much appreciated
It becomes very simple to sketch as all the barriers are single celled linings, the arrows drawn here are just for your understanding so can during the exam make an even simplified rough diagram.
For the no. of phospholipid layers count every line 2 times or simply double, 5 becomes 10 and 4 becomes 8.
Whereas phospholipid bilayer and cell membrane are the same thing.

IMG_20180530_200322.jpg
 
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It becomes very simple to sketch as all the barriers are single celled linings, the arrows drawn here are just for your understanding so can during the exam make an even simplified rough diagram.
For the no. of phospholipid layers count every line 2 times or simply double, 5 becomes 10 and 4 becomes 8.
Whereas phospholipid bilayer and cell membrane are the same thing.

View attachment 63721
Thanks alotttt it was really helpful.
 
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As stated stroke volume is volume of blood pumped by EACH contraction of a ventricle.
So as ventricular end-diastolic volume increases,so will the volume of blood pumped.So A and B are wrong.
but obviously volume pumped will not be proportional to volume pumped,which kinda makes sense because myogenic nature of heart isin't that perfect and power of contraction to pump blood is the same so it will be much difficult to push all the blood!.
So I would say answer is D!
 
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