Some microorganisms are difficult to culture because they require very specific growth factors to flourish. For example, Neisseria gonorrhoeae is difficult to culture because it requires blood, hemoglobin, many amino acids and many vitamins to grow. Neisseria gonorrhoeae, is an example of what type of organism?

• A. A halophilic organism.
• B. A photoheterotrophic organism.
• C. A fastidious organism.
• D. A facultative anaerobic organism.

Answer: (C)

Verified step by step guidance

1. Understand the term 'fastidious organism': Fastidious organisms are those that have complex nutritional requirements and need specific growth factors to thrive.
2. Identify the characteristics of Neisseria gonorrhoeae: It requires blood, hemoglobin, many amino acids, and vitamins for growth, indicating it has specific and complex nutritional needs.
3. Compare with other options: A halophilic organism thrives in high salt concentrations, which is not relevant here. A photoheterotrophic organism uses light for energy and organic compounds as a carbon source, which does not match the description. A facultative anaerobic organism can grow with or without oxygen, which is not the focus of the problem.
4. Relate the characteristics of Neisseria gonorrhoeae to the definition of a fastidious organism: Since it requires specific nutrients and conditions, it fits the definition of a fastidious organism.
5. Conclude that Neisseria gonorrhoeae is best described as a fastidious organism due to its specific growth requirements.