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# A level Biology blood maths exam-style question help watch

1. An adult human has approximately 5 dm3 of blood, which circulates about once a minute.
100 cm3 of arterial blood carries 19 cm3 of oxygen. 100 cm3 of venous blood carries 12.5 cm3 of oxygen.
What is the approximate volume in cm3 of oxygen taken up per minute in the lungs?
a 32.5
b 65
c 325
d 950 (1 mark)

I got c and the mark scheme says d. I wondered if anyone else gets this answer as the question is from Kerboodle and there are loads of other mistakes for other questions.
Thanks
2. Oh and this question
Which of the following statements is/are correct about the uptake and transport of water in plants?

1 Water transported by the symplast pathway enters root hair cells down a water potential gradient.

2 Water is transported in xylem by the symplast and apoplast pathways to reach the leaves.

3 Water transported by the apoplast pathway through plasmodesmata must pass through cell surface membranes of endodermal cells.
a 1 only
b 3 only
c 1 and 3 only
d 2 and 3 only (1 mark)
3. bump
4. And this one!
The diagram shows the effect of three different concentrations of carbon dioxide on the oxygen dissociation curve for human haemoglobin. (the diagram basically shows the bohr effect)
What effect does carbon dioxide have on haemoglobin?

a It makes it less efficient at taking up oxygen and also less efficient at releasing it.
b It makes it less efficient at taking up oxygen and more efficient at releasing it.
c It makes it more efficient at taking up oxygen and also more efficient at releasing it.
d It makes it more efficient at taking up oxygen and less efficient at releasing it.
(1 mark)
5. (Original post by Tuffyandtab)
Oh and this question
Which of the following statements is/are correct about the uptake and transport of water in plants?

1 Water transported by the symplast pathway enters root hair cells down a water potential gradient.

2 Water is transported in xylem by the symplast and apoplast pathways to reach the leaves.

3 Water transported by the apoplast pathway through plasmodesmata must pass through cell surface membranes of endodermal cells.
[/font]1 only
[/font]3 only
[/font]1 and 3 only
[/font]2 and 3 only ([/font])
(Original post by Tuffyandtab)
An adult human has approximately 5 dm3 of blood, which circulates about once a minute.
100 cm3 of arterial blood carries 19 cm3 of oxygen. 100 cm3 of venous blood carries 12.5 cm3 of oxygen.
What is the approximate volume in cm3 of oxygen taken up per minute in the lungs?
a 32.5
b 65
c 325
d 950 (1 mark)

I got c and the mark scheme says d. I wondered if anyone else gets this answer as the question is from Kerboodle and there are loads of other mistakes for other questions.
Thanks
yh I also got 325 so there must be a glitch or something, and for the other one I got C but i'm not entirely sure
6. (Original post by Tuffyandtab)
And this one!
[/font]
[/font]
[/font]
a [/font]
b [/font]
c [/font]
d [/font]
[/font][/font][/font]
C as well
7. (Original post by TheAlphaParticle)
yh I also got 325 so there must be a glitch or something, and for the other one I got C but i'm not entirely sure
Good good. For the one about water transport I put A because shouldn't point 3 be about the symplast pathway? The mark scheme did say c like you

(Original post by TheAlphaParticle)
C as well
Yes I got that as well, but mark scheme said d. I think we are right.
8. (Original post by TheAlphaParticle)
yh I also got 325 so there must be a glitch or something, and for the other one I got C but i'm not entirely sure
Actually I think youre right about the 2nd one. It is just the plasmodesmata bit that confused me as I thought it was only symplast, but I guess the water has reached the casparian strip.

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