A level Biology: Post your doubts here!

[roxylara]

Which is NOT a way in which energy is lost between a producer and a primary consumer?
A. As chemical energy in the faeces if a primary consumer
B. As chemical energy in roots that are not eaten by primary consumer
C. As heat from respiration in the cells of a primary consumer
D. As heat from respiration in the cells of the producer

I think it's B

 

[oahmed64]

Yeah I wonder its C ,there was some other ame Q in another year but it was B

shouldnt it be A since it is a non competitve inhibitor so it changes the shape of the active site right?

 

[joanna omar]

Which is NOT a way in which energy is lost between a producer and a primary consumer?
A. As chemical energy in the faeces if a primary consumer
B. As chemical energy in roots that are not eaten by primary consumer
C. As heat from respiration in the cells of a primary consumer
D. As heat from respiration in the cells of the producer

I think it's B

Yeaaah I think it is B as well cuz actually this energy is not taken as it wont be eaten !

 

[joanna omar]

shouldnt it be A since it is a non competitve inhibitor so it changes the shape of the active site right?

Remind me Which Q was this?

 

[ZaqZainab]

Yeaaah I think it is B as well cuz actually this energy is not taken as it wont be eaten !

How sure are you that it won't be eaten there are animals who eat roots like a bandicoot it eats root
idk the answer but i would go for A Its not between the producer and primary its between the primary and secondary

 

[Snowysangel]

Could someone one please answer these! Cause according to the marking scheme, tissue fluid has the same composition as blood plasma (including protei content)...but it could be wrong cause they're not the actual cie marking schemes

 

[Snowysangel]

In the second one, doesnt the trachea have epithelium rather than epidermis?

 

[joanna omar]

View attachment 37974 View attachment 37976 Could someone one please answer these! Cause according to the marking scheme, tissue fluid has the same composition as blood plasma (including protei content)...but it could be wrong cause they're not the actual cie marking schemes

27) I guess C as tissur fluid lacks plasma proteins
31) A as cholera is caused by feeding on contimated food from sewage or drinking continmated water
while 2 and 3 causes T.B

 

[Snowysangel]

27) I guess C as tissur fluid lacks plasma proteins
31) A as cholera is caused by feeding on contimated food from sewage or drinking continmated water
while 2 and 3 causes T.B

27 is B according to the marking scheme on xtremepapers. And why doesn't unpasteurized milk spread cholera?

 

[Snowysangel]

27) I guess C as tissur fluid lacks plasma proteins
31) A as cholera is caused by feeding on contimated food from sewage or drinking continmated water
while 2 and 3 causes T.B

Can the answers on xtremepapers be wrong?

 

[joanna omar]

27 is B according to the marking scheme on xtremepapers. And why doesn't unpasteurized milk spread cholera?

it's not the unpasteurized milk for cholera as its is caused by a virus and the milk if it not pasteurized would contain bacteria leading to T.B..

 

[joanna omar]

Can the answers on xtremepapers be wrong?

I don't Maybe but I am not sure u better check the ER for this paper

 

[ZaqZainab]

Can the answers on xtremepapers be wrong?

yes there are chances

 

[joanna omar]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w10_qp_12.pdf

Anyone please, I Have doubts in this paper !!
Q) 28 ........ why not its A ?
Q) 33 .......Why not D ?
Q) 36 ...... why is it D eventho examiner report said it cant be that it will always cause human to die

 

[roxylara]

A human aorta has a lumen width of 2cm. A human red blood cell has a diameter of 7um. How many red blood cells could be laid end to end across the diameter of the aorta lumen?

A. 2.9 x 10-3
B. 2.9 x 10-2
C. 2.9 x 102 (10 raised to the power 2)
D. 2.9 x 103 (10 raised to the power 3)

 

[joanna omar]

A human aorta has a lumen width of 2cm. A human red blood cell has a diameter of 7um. How many red blood cells could be laid end to end across the diameter of the aorta lumen?

A. 2.9 x 10-3
B. 2.9 x 10-2
C. 2.9 x 102 (10 raised to the power 2)
D. 2.9 x 103 (10 raised to the power 3)

IS IT D ?

 

[ZaqZainab]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w10_qp_12.pdf

Anyone please, I Have doubts in this paper !!
Q) 28 ........ why not its A ?
Q) 33 .......Why not D ?
Q) 36 ...... why is it D eventho examiner report said it cant be that it will always cause human to die

Q28) as hey said ALL blood vessels if you see capillaries don't have any of those but endothelial and arteries and veins too have endothelial this
capillaries don't have collages elastic or smooth muscle
Q33) 3 is not correct that's why.
if it was correct then the Oxygen in the alveolar would diffuse in to the the blood and would give more O2 concentration in the veins (1,2 is correct)
Q)36 i would go for B :/ I have no idea about this one

 

[VelaneDeBeaute]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w10_qp_12.pdf
Q) 36 ...... why is it D eventho examiner report said it cant be that it will always cause human to die

About the 36th one, D is the only correct option. The question was 'Which is NOT supported by the data'. The data shows that S. aureus causes deaths, but inferring from the declining pattern of the first column, we see that the rate for deaths from the classic S. aureus falls. That supports the idea that the classic strain of S. aureus is treatable. Hence, the statement that S. aureus will ALWAYS cause humans to die is wrong.
I think you just misread the question. Read it again with focus and concentration. You'll get it.

 

[VelaneDeBeaute]

27 is B according to the marking scheme on xtremepapers. And why doesn't unpasteurized milk spread cholera?

The right answer to 27 is B. The column of proteins refers to all types of proteins, and smaller proteins, polypeptides and amino acids do exist in the tissue fluid because they are able to pass through the capillary gaps. When the book content says that 'Plasma proteins are retained in the capillary', the text is referring to the 'larger' protein molecules which cannot cross the capillary wall.

 

[joanna omar]

About the 36th one, D is the only correct option. The question was 'Which is NOT supported by the data'. The data shows that S. aureus causes deaths, but inferring from the declining pattern of the first column, we see that the rate for deaths from the classic S. aureus falls. That supports the idea that the classic strain of S. aureus is treatable. Hence, the statement that S. aureus will ALWAYS cause humans to die is wrong.
I think you just misread the question. Read it again with focus and concentration. You'll get it.

True thats how my mistakes are mainly mis-reading the Q 's
THANKS A BUNCH