Which of the following is not pathogenic?

Options

A. Yeast
B. Albugo
C. Alternaria
D. Ustilago

Answer

To determine which of the following organisms is not pathogenic, we need to analyze each option provided. Here’s a step-by-step solution:

### Step 1: Identify the Organisms
We need to look at the options given in the question. The organisms mentioned include yeast, Albugo, Alternaria, and Astirogo.

### Step 2: Analyze Yeast
- Yeast is a type of fungi that belongs to the kingdom Fungi.
- It is eukaryotic and primarily single-celled.
- Yeast is commonly used in food production, especially in the fermentation process (e.g., making bread and alcoholic beverages).
- Since yeast is safe for consumption and is used in food preparation, it is considered non-pathogenic.

### Step 3: Analyze Albugo
- Albugo is a type of algae that is known to be parasitic.
- It has pathogenic properties, meaning it can cause disease in its host.

### Step 4: Analyze Alternaria
- Alternaria is a genus of fungi that is known to be pathogenic.
- It can cause various plant diseases and is also associated with allergic reactions in humans.

### Step 5: Analyze Astirogo
- Astirogo is a type of parasitic fungi.
- Like Albugo and Alternaria, it also exhibits pathogenic properties.

### Conclusion
After analyzing all the options:
- Yeast is the only organism that is non-pathogenic.
- Therefore, the correct answer to the question "Which of the following is not pathogenic?" is **Yeast**.