Growth on the macconkey agar and na plates was recorded as good growth poor growth. what did you use to establish what constituted good growth?

Microbiological experiments are conducted to analyse the growth pattern and capabilities to consume a substrate and undergo multiplcation in number and mass for multiple microbes. Generally, agar or brotg remains the preliminary substrates for analysis of microbial growth. The usual practices include dilution of the stock solution, plating on the plate and observations after a growth period of atleast 24 hours. The number of colonies appearing on the plate are observed and counted manually or automatically. Using appropriate mathematical formula, the actual number of microbial units can be calculated in thw stock solution.

Thus, based upon number of colonies appearing on the plate, the growth can be distinguished as following:

1. No growth: this refers to no appearance of any growth on plate, neither diluted nor stock solution.

2. Poor growth: Qualitatively, poor growth refers to appearance of only 10 or less number of colonies in the stock solution. Such stocks are further concentrated and re-analysed for growth.

3. Good growth: Good microbial growth refers to appearance of 15 or more colonies in the stock solution. Such solutions are considered as moderately concentrated in nature.

Thus, based upon the above mentioned qualitative analyses, the nature of growth can be determined easily.

c is the correct answer!