Question

For the three types of media in Table 6.1, which medium (or media) is/are chemically defined?

Medium A Medium B Medium C

Na2HPO4 Tide detergent Glucose

KH2PO4 Na2HPO4 Peptone

MgSO4 KH2PO4 (NH4)2SO4

CaCl2 MgSO4 KH2PO2

NaHCO3 (NH4)2SO4 Na2HPO4

Answer 1

Medium A, containing Na2HPO4, KH2PO4, MgSO4, CaCl2, and NaHCO3, is the chemically defined medium as all components have a known chemical composition.

Step-by-step explanation:

When looking at the components listed in the table, it appears that Medium A is the chemically defined medium. This is because Medium A contains ingredients such as Na2HPO4, KH2PO4, MgSO4, CaCl2, and NaHCO3, all of which are pure chemicals with known compositions. None of these components are extracts or digests of biological material, which would indicate a complex medium.

On the other hand, Medium B consists of commercial products such as Tide detergent, which could have variable components, making it a complex medium. Furthermore, Medium C contains peptone, which is a digest of animal protein, again indicating a complex medium. In summary, the only medium from the table that is chemically defined is Medium A.