A scientist was studying the production of a protein that was released by an animal cell into a culture medium, she found that the protein only appeared in the culture medium after the added a few drops of a hormone to the cell. Before adding the hormone, she labelled the protein inside the cell with a fluorescent dye and looked at the cell under the lgiht microscope. The dye was seen in flattened sheets and tube. like structures throughout the cell, and in stacks of flattened sac-like structures. after adding the hormone, the dye was aslo seen as small dots clustered against the cell membrane, Which statement most likely explains these observations?

Options

A. The hormone stimulates protein synthesis in the cell vacuole, the protein is then passed to the Golgi apparatus, and eventually passess through the cell membrane by passive diffusion.
B. The hormone triggers the synthesis of the protein in the endoplasmic reticulum and it is then secreted outside of the cell via channel proteins in the cell membrane
C. The protein is made in the endoplasmic reticulum, is passed to the Golgi appartus and is secreted through hormone-stimulated exocytosis.
D. The protein is made in the Golgi apparatus, is passed to the endoplasmic recticulum and is secreted through hormone-stimulated pinocytosis.

Explanation

To solve the question, we need to analyze the observations made by the scientist in the experiment regarding the protein production and release in the animal cell after the addition of a hormone. Here’s a step-by-step breakdown of the reasoning:

### Step 1: Understanding the Experiment
The scientist is studying a protein produced by an animal cell that is released into the culture medium. The protein only appears in the medium after adding a hormone, indicating that the hormone plays a crucial role in stimulating the production and release of this protein.

**Hint:** Focus on the role of the hormone in the process of protein synthesis and secretion.

### Step 2: Observing the Protein Before Hormone Addition
Before the addition of the hormone, the fluorescent dye labeled the protein inside the cell. The dye was observed in flattened sheets and tube-like structures (which are likely the endoplasmic reticulum) and in stacks of flattened sac-like structures (which represent the Golgi apparatus).

**Hint:** Identify the cellular structures involved in protein synthesis and processing.

### Step 3: Observing the Protein After Hormone Addition
After the hormone was added, the dye was seen as small dots clustered against the cell membrane. This suggests that the protein is being transported to the cell membrane for secretion.

**Hint:** Consider how proteins are transported out of the cell after synthesis.

### Step 4: Evaluating the Statements
Now, we need to evaluate the provided statements based on our understanding of cellular processes:

1. **First Statement:** The hormone stimulates protein synthesis in the cell vacuole.
- **Evaluation:** This is incorrect because protein synthesis occurs in ribosomes, not vacuoles.

2. **Second Statement:** The hormone triggers the synthesis of protein in the endoplasmic reticulum and it is then secreted outside the cell via channel proteins in the cell membrane.
- **Evaluation:** This is incorrect because channel proteins do not facilitate the transport of macromolecules like proteins.

3. **Third Statement:** The protein is made in the endoplasmic reticulum, is passed to the Golgi apparatus, and is secreted through hormone-stimulated exocytosis.
- **Evaluation:** This is correct as it accurately describes the process of protein synthesis and secretion.

4. **Fourth Statement:** The protein is made in the Golgi apparatus, passed through the endoplasmic reticulum, and secreted through hormone-stimulated pinocytosis.
- **Evaluation:** This is incorrect because proteins are synthesized in the endoplasmic reticulum, not the Golgi apparatus.

### Conclusion
Based on the evaluations, the most likely explanation for the observations is that the protein is made in the endoplasmic reticulum, passed to the Golgi apparatus, and secreted through hormone-stimulated exocytosis.

**Final Answer:** The correct statement is: "The protein is made in the endoplasmic reticulum, is passed to the Golgi apparatus, and is secreted through hormone-stimulated exocytosis."

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