Question

Q.22 In humans, the epithelium which separates air and blood is only:

A)I cell thick

B) 3 cells thick

C) 2 cells thick

D) 4 cells thick​

Answer 1

2 cells thick(c)........

Answer 2

Answer:

2 cells thick

Explanation:

Because the respiratory surface is very thin in humans and it consists of single layered alveoli and single layered blood capillaries so it is 2 cells thick