How is milk converted into curd? Can the milk be obtained again from the curd? What kind of change is this? [3 MARKS]

Preparation of curd: 1 Mark
Statement: 1 Mark
Kind of change: 1 Mark

Milk is taken in a vessel and a small quantity of curd is added into it. It is stirred and kept aside for few hours without any disturbance. Finally, the milk is converted into curd.

However, curd formed cannot be converted into milk again.

This indicates that it is an irreversible change.