A membrane-lined system of channels present throughout the cytoplasm is

Options

A. Endoplasmic reticulum
B. Golgi apparatus
C. Microtubules
D. Both B and C

Answer

To solve the question "A membrane-lined system of channels present throughout the cytoplasm is", we will analyze the options provided and identify the correct answer step by step.

### Step 1: Understand the Question
The question asks for a specific structure in the cell that is characterized as a "membrane-lined system of channels" and is found throughout the cytoplasm.

### Step 2: Analyze the Options
We have four options to consider:
- A) Endoplasmic reticulum
- B) Golgi apparatus
- C) Microtubules
- D) Both B and C

### Step 3: Evaluate Each Option
1. **Endoplasmic Reticulum (ER)**:
- The ER is indeed a membrane-lined system of channels. It consists of a network of flattened membrane-bound sacs and tubules that extend throughout the cytoplasm. It is involved in the synthesis of proteins, lipids, and carbohydrates. The ER is continuous with the nuclear membrane, making it a significant structure in the cytoplasm.

2. **Golgi Apparatus**:
- The Golgi apparatus is involved in modifying, sorting, and packaging proteins and lipids but is not primarily described as a system of channels throughout the cytoplasm. It is more of a stack of membrane-bound vesicles.

3. **Microtubules**:
- Microtubules are part of the cytoskeleton and are not membrane-lined channels. They provide structural support and are involved in intracellular transport but do not fit the description given in the question.

4. **Both B and C**:
- Since neither the Golgi apparatus nor microtubules fit the description of a membrane-lined system of channels, this option is also incorrect.

### Step 4: Conclusion
Based on the analysis, the only option that fits the description of a "membrane-lined system of channels present throughout the cytoplasm" is **A) Endoplasmic reticulum**.

### Final Answer
The correct answer is **A) Endoplasmic reticulum**.

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