Answer: A culture medium of which the precise chemical composition is known is called a defined or synthetic medium.
Step-by-step explanation:
In laboratory settings, scientists often need to grow and study microorganisms or cells in a controlled environment. To achieve this, they use culture media, which are nutrient-rich substances that provide essential elements and compounds necessary for the growth and survival of the organisms.
A defined or synthetic medium is a culture medium whose precise chemical composition is known and carefully formulated. It contains specific amounts of known nutrients, such as carbohydrates, amino acids, vitamins, minerals, and growth factors. The composition of a defined medium can be adjusted and manipulated to meet the specific requirements of the organisms being cultured.
Using a defined medium offers several advantages. First, it provides researchers with precise control over the nutrients and conditions available to the organisms, allowing for reproducibility and standardization of experiments. Second, it allows the study of specific metabolic pathways or the effects of individual nutrients on the growth and behavior of the organisms. Third, it facilitates the identification and isolation of specific metabolic products or byproducts.
On the other hand, some microorganisms or cells may have complex nutritional requirements that are not fully understood or cannot be replicated in a defined medium. In such cases, researchers may use complex or undefined media that contain extracts from natural sources, such as yeast or plant extracts, to provide a broader range of nutrients.
In summary, a culture medium with a known and precisely defined chemical composition is called a defined or synthetic medium. It is carefully formulated to provide specific nutrients to support the growth and study of microorganisms or cells in a controlled laboratory environment.