Which of the following is produced by the process of fermentation by microbes?

The microorganism that converts milk into curd is ..........

Which organisms are responsible for the conversion of milk into curd?

Milk is converted into curd by . . . . . . .

How many of the following statements are correct regarding the process of converting milk into curd?
$I -$ The bacteria responsible for this process are $LAB$.
$II -$ $LAB$ produces acids that coagulate the milk.
$III -$ The protein present in milk is partially digested.
$IV -$ It increases the nutritional quality by increasing the amount of Vitamin $B_{12}$.

The dough used for making dosa and idli is fermented by which organisms,and what causes it to appear puffed up?