What are vacuoles?

Vacuoles are membrane-bound organelles primarily used for storage and transport within cells. They can hold various substances, including nutrients, waste products, or water, and are especially prominent in plant cells where they help maintain turgor pressure, contributing to cell structure and overall rigidity. Inclusions within the cytoplasm refer to non-living substances like granules or droplets that can include stored nutrients or pigments, which may be found alongside vacuoles but do not perform active cellular functions like the vacuoles do.

Considering the context of the other options, protein synthesis is primarily carried out by ribosomes and the endoplasmic reticulum, while structures responsible for cellular respiration are mainly mitochondria. The cytoskeleton comprises various protein filaments that provide structural support and shape to the cell, rather than being involved in storage like vacuoles. Therefore, defining vacuoles as inclusions within the cytoplasm captures their role accurately within the cellular context.