Which of the following is an algal source of $SCP$?

$(A)$ The shift from grain to meat diets creates more demands for cereals. Why?
$(B)$ $A$ $250 \ kg$ cow produces $200 \ g$ of protein per day, but $250 \ g$ of $Methylophilus \ methylotrophus$ can produce $25 \ \text{tonnes}$ of protein. Name this emerging area of research. Explain its benefits.

The advantages of single cell proteins are:
$I$. Easy to grow
$II$. Nutrient rich
$III$. High yield
Choose the correct option.

Which microorganism produces 200 g of protein in a single day?

An alga which can be employed as food for human beings is

Consider the following statements $(I-IV)$ and select the option containing the correct answer.
$I.$ The unicellular $Spirulina$ can produce large quantities of food rich in protein,minerals,and vitamins.
$II.$ Based on body weight,the microorganism $Methylophilus$ $methylotrophus$ can produce much more protein in a day than a cow.
$III.$ Common button mushrooms are a rich source of Vitamin-$C$.
$IV.$ $A$ variety of rice has been developed that is rich in calcium.