Use the following information to answer questions 1 and 2. Two culture media were inoculated with four different bacteria. After incubation, the following results were obtained:

Medium 1 is
a. Selective
b. Differential
c. Both selective and differential

Verified step by step guidance

1. Step 1: Understand the definitions of selective and differential media. Selective media allow the growth of certain bacteria while inhibiting others. Differential media allow the differentiation of bacteria based on their biological characteristics, often indicated by color changes or other visible reactions.
2. Step 2: Examine the results of bacterial growth on Medium 1. Identify which bacteria grew and which did not. If some bacteria are inhibited, this suggests selectivity.
3. Step 3: Look for any visible changes in the medium or bacterial colonies on Medium 1, such as color changes, precipitate formation, or changes in colony morphology. These changes indicate differential properties.
4. Step 4: Determine if Medium 1 both inhibits some bacteria (selective) and causes visible changes that differentiate bacteria (differential).
5. Step 5: Based on your observations, conclude whether Medium 1 is selective, differential, or both selective and differential.

Key Concepts

Selective Media

Selective media contain specific agents that inhibit the growth of certain microorganisms while allowing others to grow. This property helps isolate particular types of bacteria from mixed samples by suppressing unwanted species.

Differential Media

Differential media include indicators that reveal differences between bacterial species based on their metabolic properties, such as color changes or precipitate formation. This allows identification or distinction of bacteria within a mixed culture.

Interpreting Culture Results

Analyzing bacterial growth patterns and color changes on culture media helps determine whether the medium is selective, differential, or both. Understanding these results requires knowledge of bacterial metabolism and media composition.