Riboflavin (Vitamin $B_2$) is produced by which of the following microorganisms?

Which of the following enzymes are used to clarify fruit juices?
$(i)$ Lipase
(ii) Protease
(iii) RNase
(iv) Pectinase

Streptokinase produced by the bacterium $Streptococcus$ is used for:

Read the sentence with two blanks ($a$ and $b$): "The medicine used for patients of .....$(a)$..... is obtained from the species of organism .....$(b)$.....". Which is the correct option for the two blanks?

Which of the following is a commercial blood cholesterol-lowering agent?

Citric acid is produced by