Question

1. Drag the statements to the correct type of medium to compare and contrast different examples of selective and differential media Selective media Enterococcus faecalis broth MacConkey Agar Lowenstein-Jensen Sabouraud's Agar Differential Media Blood Agar Mannitol Salt Agar Triple-Sugar Iron Agar MacConkey Agar 2. A bacterial cell measures 2.5 micrometers (mm) in length. what is the size of this cell in nanometers(nm)? 3. Select the characteristics of complex media used in microbial culturing.( check all that apply) 4. The terms "sterile" and "pure" can be used interchangeably when discussing cultures, because they both refer to a culture that has not been contaminated. True or False 5. Move the terms into the correct empty boxes to complete this concept map describing the relationship between stain types. 6. Select the type of media where the chemical composition is precisely known.

Answer 1

1. Selective Media

• Enterococcus Faecalis Broth – This is a type of selective medium because the sodium azide present in it allows the growth of only a specific type of micro-organism which is fecal enterococci
• MacConkey Agar – This type of media is specific for the growth of gram negative enteric due to the presence of bile as well as crystal violet
• Lowenstein-Jensen – It allows the growth of only mycobacterium due to the presence of malachite gren
• Sabouraud’s – It specifically allows growth of only fungi due to its high acidic nature
• Mannitol Salt Agar – This is selective media as it helps in isolating pathogenic strains of staphylococci.

Differential Media:-

• Blood Agar – This is an blood enriched media which is used for bacterial growth and is made of trypticase soya agar mixed with 5% of sheep blood. It allows the growth of many bacterial species like streptococci. It is differential as it helps in distinguishing different bacteria species based on its ability to break RBC.
• Triple sugar iron agar – This media is differential as it helps in distinguishing between micro-organism that are able to ferment sugar to produce hydrogen sulphide and those that are not.
• MacConkey Agar – It is differential as it helps in isolating the enteric based on their ability to ferment lactose.