13. A staining that divides organisms into two groups depending on their staining is referred to as __________. a) simple staining b) differential stain c) structural staining d) morphological staining

4) In Gram Stain the bacteria that becomes colorless after washing with alcohol or acetone is the: a) Gram +ve bacteria b) Gram -ve bacteria c) ) Gram neutral bacteria d) archaebacteria e) b & c5) Antimetabolites include: a) Sulfonamides b) Tetracyclins c) Trimethoprim d) all of the above e) a and c6) Oil immersion is used in light microscope because: a) it increases  only b) it decreases  only c) it increases the / n sin  value d) it decreases / n sin  e) same refractive index as the glass slide

a) explain in your own words how to do a nitrate reduction test to identify unknown bacteria   b) explain in your own words how to perform a phenol red broth (prb) test to help identify unknown bacteria

question 6