Q1.Micro-organisms that grow in milk and convert it to curd is commonly called
Answer : Option AExplaination / Solution:
The micro-organisms that grow in milk and convert it to curd is commonly called lactic acid bacteria. Micro-organism such as Lactobacillus and others commonly called as lactic acid bacteria (LAB).
Q3.The puffed-up appearance of dough is due to production of
Answer : Option BExplaination / Solution: The puffed-up appearance of dough is due to production of CO2 gas. Baking soda (sodium hydrogen carbonate) on heating release carbon dioxide gas along with sodium carbonate.
Q9.First organic acid produced by microbial fermentation is
Answer : Option DExplaination / Solution:
Lactic acid occurs in two isomeric forms i.e. L (+) and D (-) isomers, and as a racemic mixture (DL-lactic acid). The isolation of lactic acid from milk was done in 1798. It was the first organic acid produced by microorganisms in 1880. Today, lactic acid is competitively produced both by microbiological and chemical methods.