Question
Simple cuboidal epithelial cells line the ducts of certain human exocrine glands. Various materials are transported into or out of the cells by diffusion. (The formula for the surface area of a cube is \(6\times S^2\) , and the formula for the volume of a cube is\( S^3\) , where S = the length of a side of the cube.) Which of the following cube-shaped cells would be most efficient in removing waste by diffusion?
▶️Answer/Explanation
Ans:A
This option is correct. It demonstrates the ability to calculate surface area-to- volume ratios and predict their effects on a cell’s ability to exchange materials with its environment. The cell shown in A has the greatest surface area-to- volume ratio at 0.6:1.
Question
The function of which of the following structures is NOT directly related to diffusion or active transport across its membranes?
(A) Aorta
(B) Small intestine
(C) Nephron tubule
(D) Capillary
(E) Alveolus
Answer/Explanation
Ans:A