The endomembrane system primarily functions to?

• A. Generate energy for the cell.
• B. Break down toxins only outside the cell.
• C. House genetic material.
• D. Synthesize, modify, package, and transport proteins and lipids within the cell.

Answer: (D)

The endomembrane system is a coordinated network of membranes that handles the production and trafficking of cellular components. It includes the nuclear envelope, the endoplasmic reticulum (rough and smooth), the Golgi apparatus, lysosomes, vesicles, and the plasma membrane. Its main job is to synthesize, modify, package, and transport proteins and lipids within the cell, directing them to their proper destinations such as the cell membrane, lysosomes, or outside the cell.

Energy generation happens primarily in mitochondria (and chloroplasts in plants), not through the endomembrane system. Genetic material is housed in the nucleus, not within the endomembrane network. Toxin breakdown can occur in organelles like lysosomes or the smooth ER, but it’s not correctly described as happening only outside the cell.