Question

What would happen if there were no stomata on the leaves?

Answer 1

If there wasnt a stomata then there will be no gas exchange the carbon dioxide wouldnt be able to move further into the plant and then photosynthesis won't be able to occur. 
Another reason is that there will be no transpiration meaning the leaves wont get water. 
If this is the case the leaf will die.
So it is a very essential part of a leaf!

Answer 2

if there is no stomata then there will be no respiration in plants , no respiration means no plants(normal)....
there are plants which doesn't have stomata...they respire through roots, stem etc.