Which of the following groups is primarily involved in synthesizing molecules needed by the cell?

• A. Lysosome, vacuole, ribosome
• B. Vacuole, rough endoplasmic reticulum, smooth endoplasmic reticulum
• C. Smooth endoplasmic reticulum, ribosome, vacuole
• D. Rough endoplasmic reticulum, lysosome, vacuole
• E. Ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum

Answer: (E)

Verified step by step guidance

1. Understand the role of each organelle mentioned in the options: Lysosome, vacuole, ribosome, rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER).
2. Ribosomes are responsible for protein synthesis. They can be found floating freely in the cytoplasm or attached to the rough endoplasmic reticulum.
3. The rough endoplasmic reticulum (RER) is involved in the synthesis of proteins that are either secreted from the cell, incorporated into the cell's plasma membrane, or sent to an organelle. The 'rough' appearance is due to the presence of ribosomes on its surface.
4. The smooth endoplasmic reticulum (SER) is involved in the synthesis of lipids and steroids, metabolism of carbohydrates, and detoxification of drugs and poisons. It does not have ribosomes on its surface, hence the 'smooth' appearance.
5. Identify the group that includes ribosome, rough endoplasmic reticulum, and smooth endoplasmic reticulum, as these are the organelles primarily involved in synthesizing molecules needed by the cell.