Question

What do you think will happen to the deers and the lion if all the grass dries up

Answer 1

according to biological sciences terms..
All animal kingdom of lions may suffer.
beacuse if all grass has dried up, no food for deers.
so without that they can't survive . so deers die slowly.
so if lions depand on deers, lions may also die.
and kingdom of lions may vanish.

Answer 2

If all the grass dries up deers will eat small shrubs
And if the shrubs too dry then the food chain will be broken and Deers will become extinct.
Talking about lions.
Lions do not only eat deers.
So they can eat other animals like Giraffe since giraffe can eat food from trees too and grass is dried so other small animals would also have died.
So only large animals like Elephant and Giraffe would be left
and the lions number will also decrease since they will not get enough food as they got earlier.