The negatively geotrophic and unbranched hyphae in Rhizopus are known as

Answer

To solve the question regarding the negatively geotrophic and unbranched hyphae in Rhizopus, we can follow these steps:

### Step 1: Understand the terminology
- **Negatively geotrophic**: This refers to the growth of an organism away from gravity. In fungi, this means that the hyphae grow upwards or away from the substrate.
- **Unbranched hyphae**: These are hyphae that do not have branches and grow in a straight line.

### Step 2: Identify the types of hyphae in Rhizopus
- **Sporangiophores**: These are specialized hyphae that bear sporangia, which are structures that produce and contain spores.
- **Zygophores**: These are specialized hyphal branches that are involved in sexual reproduction, leading to the formation of zygospores.
- **Stoloniferous**: This term refers to hyphae that spread horizontally and can give rise to new colonies.

### Step 3: Analyze the options
1. **Sporangiophores**: These are indeed unbranched and grow upwards, making them negatively geotrophic.
2. **Zygophores**: These are involved in reproduction but are not specifically described as unbranched.
3. **Stoloniferous**: These are branched and spread horizontally, which does not fit the description.

### Step 4: Conclusion
Based on the definitions and characteristics of the hyphae:
- The negatively geotrophic and unbranched hyphae in Rhizopus are known as **Sporangiophores**.

### Final Answer
1. Sporangiophores

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