which one is without an external covering ?

Options

A. Lysosome
B. Gogli apparatus
C. Centrosome
D. Centrioles

Answer

To determine which structure is without an external covering, we will analyze each of the given options: Lysosome, Golgi apparatus, Centrosome, and Centrioles.

### Step-by-Step Solution:

1. **Analyze Lysosome**:
- Lysosomes are membrane-bound organelles.
- They have a single membrane that encloses their contents.
- Function: They are involved in the degradation and digestion of cellular waste.

**Hint**: Remember that lysosomes are known for their digestive enzymes and have a protective membrane.

2. **Analyze Golgi Apparatus**:
- The Golgi apparatus is also a membrane-bound structure.
- It consists of flattened membranous sacs and is involved in modifying, sorting, and packaging proteins.

**Hint**: Think about how the Golgi apparatus processes proteins and its structure as a series of membranes.

3. **Analyze Centrosome**:
- The centrosome is not membrane-bound.
- It is composed of two centrioles arranged perpendicular to each other.
- Function: It organizes microtubules and is crucial for cell division.

**Hint**: Consider the role of the centrosome in organizing microtubules and its structural composition.

4. **Analyze Centrioles**:
- Centrioles are cylindrical structures that are part of the centrosome.
- They are also not membrane-bound and are involved in cell division.

**Hint**: Remember that centrioles are the building blocks of the centrosome and are essential for cell division.

### Conclusion:
After analyzing all options, the structure that is without an external covering is the **Centrosome**. It is made up of two centrioles and does not have a membrane surrounding it.

### Final Answer:
**Centrosome** is the correct answer as it is without an external covering.