Question

Why we have many alveoli

Answer 1

We have many alveoli because, there are many cells present in our body.
And every cell require oxygen for cellular processes.

So, to fulfill the need of air suppy, we have many aleoli with a ballon shape to provide greater surface area.

Answer 2

As we know our body is made up of many cell.Every cell required oxygen for their cellular function and to fulfil the of oxygen alveoli are required for the supply of oxygen.