If you could follow a small region of membrane as it flowed from organelle to organelle, which of the following sequences would you most likely observe?

Options

A. Golgi apparatus `to` lysosome`to` ER
B. Nuclear envelope `to` lysosome `to` Golgi apparatus
C. ER `to` Golgi apparatus`to` plasma membrane
D. ER `to` chloroplast `to` mitochondrion

Explanation

To solve the question about the sequence of membrane flow from organelle to organelle, we can break down the process step by step:

### Step-by-Step Solution:

1. **Understanding the Endomembrane System**:
- The endomembrane system in eukaryotic cells includes several organelles such as the endoplasmic reticulum (ER), Golgi apparatus, lysosomes, and the plasma membrane. This system is responsible for the synthesis, modification, and transport of proteins and lipids.

**Hint**: Remember that the endomembrane system consists of interconnected organelles that work together in the transport of materials.

2. **Starting Point - Endoplasmic Reticulum (ER)**:
- The process begins in the endoplasmic reticulum (ER). The ER is involved in the synthesis of proteins and lipids. Membranes can bud off from the ER.

**Hint**: Think of the ER as the starting point for many proteins and lipids that need to be processed further.

3. **Flow to the Golgi Apparatus**:
- After leaving the ER, the membrane-bound vesicles containing proteins and lipids travel to the Golgi apparatus. Here, they undergo further modifications, sorting, and packaging.

**Hint**: The Golgi apparatus acts like a post office, modifying and sending proteins and lipids to their final destinations.

4. **Transport to the Plasma Membrane**:
- Once the proteins and lipids are processed in the Golgi, they are packaged into new vesicles that can then move to the plasma membrane for secretion or incorporation into the membrane.

**Hint**: The plasma membrane is the final destination for many vesicles, where they can either release their contents outside the cell or integrate into the membrane.

5. **Conclusion**:
- Following this sequence, the most likely observable path for a small region of membrane would be: **Endoplasmic Reticulum → Golgi Apparatus → Plasma Membrane**.

### Final Answer:
The correct sequence you would most likely observe is: **Endoplasmic Reticulum → Golgi Apparatus → Plasma Membrane**.