Biology CLEP Prep Practice Exam

What kind of molecules control the passage of compounds between a cell and its environment?

1. Endoplasmic reticulum

2. Transport proteins

3. Chloroplasts

4. Ion channels

The correct answer is: Transport proteins

Transport proteins are the correct answer because they are responsible for controlling the passage of compounds between a cell and its environment. They are located in the cell membrane and are designed to only allow specific molecules to pass through. The other options, endoplasmic reticulum, chloroplasts, and ion channels, are incorrect because they do not have the same function as transport proteins. The endoplasmic reticulum is responsible for protein synthesis and modification, chloroplasts are involved in photosynthesis, and ion channels are responsible for controlling the movement of ions. These functions are important for the well-being of a cell, but they do not specifically control the passage of molecules between a cell and its environment.