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Why are the epithelial tissues that line an animal's internal organs usually only one or a few cells thick?
(i) To store food efficiently. (ii) To provide maximum strength. (iii) To allow quick exchange of materials across them. (iv) To reduce friction.
(i) To store food efficiently. (ii) To provide maximum strength. (iii) To allow quick exchange of materials across them. (iv) To reduce friction.
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Thin, single-layer lining
Materials diffuse
across quickly
_) Nutrients
Found in lungs
and blood vessels
Thick wall —
exchange is slow X
Nutrients
View Answer
The correct option is (iii) To allow quick exchange of materials across them.
A thin lining lets gases and liquids diffuse across quickly, which is why the lining of the lungs and blood vessels is just one cell thick.
Why the Lining Is Thin
One or a few cells thick
A very short distance to cross.
↓
Gases and liquids diffuse across quickly
As in lungs and blood vessels.
↓
Answer: (iii) Quick exchange of materials
