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Edexcel IGCSE Biology 1B Unofficial Mark Scheme

Starting with Q1

Parts of Lung; Windpipe, Bronchus, Bronchiole
Lung like a tree because both have many branches

When you inhale, Pressure decreases, Volume increases, Diaphragm pulls downwards and contracts, air drawn in, internal IC muscles relax, exterior IC muscles contract.

If anyone has answers to any other questions, post below, I will try to keep adding more questions.

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Reply 2
Avatar for ImiT
ImiT
8
Original post by JMR2017
Starting with Q1

Parts of Lung; Windpipe, Bronchus, Bronchiole
Lung like a tree because both have many branches

When you inhale, Pressure decreases, Volume increases, Diaphragm pulls downwards and contracts, air drawn in, internal IC muscles relax, exterior IC muscles contract.

If anyone has answers to any other questions, post below, I will try to keep adding more questions.


"Trachea" is better than windpipe
Original post by ImiT
"Trachea" is better than windpipe


They will accept both in the mark scheme
Original post by ImiT
internal intercoastal muscles contract, external intercoastal muscles relax


Are you sure? BBC Bitesize disagrees...
http://www.bbc.co.uk/education/guides/z6h4jxs/revision/2
Original post by JMR2017
Starting with Q1

Parts of Lung; Windpipe, Bronchus, Bronchiole
Lung like a tree because both have many branches

When you inhale, Pressure decreases, Volume increases, Diaphragm pulls downwards and contracts, air drawn in, internal IC muscles relax, exterior IC muscles contract.

If anyone has answers to any other questions, post below, I will try to keep adding more questions.


Is it definitely bronchiole not alveoli because it was hard to tell which it was pointing at.
Original post by LlamaLlama1730
Is it definitely bronchiole not alveoli because it was hard to tell which it was pointing at.


I think so, because they usually circle the alveoli if it was that, but they did not circle it.
Original post by JMR2017
Starting with Q1

Parts of Lung; Windpipe, Bronchus, Bronchiole
Lung like a tree because both have many branches

When you inhale, Pressure decreases, Volume increases, Diaphragm pulls downwards and contracts, air drawn in, internal IC muscles relax, exterior IC muscles contract.

If anyone has answers to any other questions, post below, I will try to keep adding more questions.

what if i put diaphragm moves down and relaxes will i still get the 3 marks coz i put everything else
Original post by eesaali128
what if i put diaphragm moves down and relaxes will i still get the 3 marks coz i put everything else


If you put 3 correct points you will get 3 marks, even if one is wrong.
Reply 9
Avatar for Deadmaus
Deadmaus
For the starch in visking tubing, was it that the water moved in through osmosis so the volume in the tubing increased.
Original post by JMR2017
If you put 3 correct points you will get 3 marks, even if one is wrong.

i put the ribs move up and out, the intercostal muscles contract, the diaphragm moves down and RELAXES so the volume increases and the pressure decreases so air is drawn in
3 marks ?
question 3:
i think these were my answers

8

5

Gg

25 percent
for the direction of the impulse it was from the head to the tail
Original post by eesaali128
i put the ribs move up and out, the intercostal muscles contract, the diaphragm moves down and RELAXES so the volume increases and the pressure decreases so air is drawn in
3 marks ?

I think you will get 3 for that because you talked about the ribs, the pressure and the volume. Definitely 2 though.
The boundaries will probs be %70 for an a* if the next paper isnt easy either as this was harder than jan 2017 and for that it was %73 for an a*
Correct me if Im wrong, for the tick boxes in the starch glucose question I think it was

All no for starch
No, Yes, Yes, No for glucose
Original post by JMR2017
I think you will get 3 for that because you talked about the ribs, the pressure and the volume. Definitely 2 though.
yeah plus it could b separate marks for ribs and intercostal muscles
Reply 17
Avatar for ihs0201
ihs0201
9
Posted from TSR Mobile

Wasn't the maltase one no as maltase is for maltose to glucose not starch to glucose?
Original post by partygoose123
question 3:
i think these were my answers

8

5

Gg

25 percent


Why was it 5? Also, why was it Gg again?
Reply 19
Avatar for rrz7
rrz7
10
Original post by Deadmaus
For the starch in visking tubing, was it that the water moved in through osmosis so the volume in the tubing increased.


yeah but u should talk about high conc to low conc etc

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