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Thread starter 4 months ago
#1
Describe and explain how you would expect the height to breadth ratio of an
epithelial cell from a lung alveolus to differ from the height to breadth ratio of a
milk-producing cell.(ratio of this cell was given as 1.2:1)

The mark sceme says this;

Ratio would be less / smaller;
Cell is thin / has large surface area / (adapted) for diffusion;

I am confused as to why ratio is smaller when an epithelial cell in alveolus is relatively wide but very thin.
0
Thread starter 4 months ago
#2
Hi,anyone help?
This question and answer have been bugging me all day!
0
4 months ago
#3
(Original post by susiebe)
Hi,anyone help?
This question and answer have been bugging me all day!
I think by breadth they mean thickness, not how wide the cell is. The MS answer suggests that it's smaller because cells in the alveolus are 'thinner' so breadth = thickness
could be wrong
0
4 months ago
#4
(Original post by susiebe)
Describe and explain how you would expect the height to breadth ratio of an
epithelial cell from a lung alveolus to differ from the height to breadth ratio of a
milk-producing cell.(ratio of this cell was given as 1.2:1)

The mark sceme says this;

Ratio would be less / smaller;
Cell is thin / has large surface area / (adapted) for diffusion;

I am confused as to why ratio is smaller when an epithelial cell in alveolus is relatively wide but very thin.
it says height to breadth ratio not surface area to volume ratio.
A milk producing cell is wider and taller due to it storing large quantities of the substrates which make up the milk in specialised vesicles hence it being taller than a epithelial cell from a lung alveolus. Th lung cell is much smaller height wise therefore the HEIGHT to BREADTH ratio is larger for a milk cell. If it said BREADTH TO HEIGHT RATIO then the epithelial cell will greater.
0
4 months ago
#5
(Original post by ilovephysmath)
I think by breadth they mean thickness, not how wide the cell is. The MS answer suggests that it's smaller because cells in the alveolus are 'thinner' so breadth = thickness
could be wrong
No breadth is how long the cell is the height is its thickness.
Imagine it as a graph where the y axis is the height and the x axis is the breadth. that should be helpful.
The larger the y axis the thicker the cell
0
Thread starter 4 months ago
#6
Many thanks!
its just clicked!
I think i was looking at a cell as more of a 2Dshape rather than a 3D shape,even though the alveolus cell would have a very small height(one cell thick height!)its still height or thickness.
Understanding the question is such a big part of A level Biology
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