Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

Which structures are considered vacuoles?

1. Saclike structures that store materials

2. Protein filaments that support the cell

3. Organelles involved in energy production

4. Molecular structures in prokaryotes

The correct answer is: Saclike structures that store materials

Vacuoles are indeed saclike structures that serve as storage compartments within a cell. They can hold a variety of materials, including nutrients, waste products, and other substances that the cell may need to manage. In plant cells, vacuoles are often large and play essential roles in maintaining turgor pressure, which helps support the structure of the plant. In animal cells, vacuoles are generally smaller and more numerous, also contributing to storage and transport functions. The other options describe different cellular components: protein filaments are part of the cytoskeleton, organelles involved in energy production refer primarily to mitochondria and chloroplasts, and molecular structures in prokaryotes generally refer to features like ribosomes or cell membranes, not vacuoles. Thus, the clarity of the first choice aligns perfectly with the definition and function of vacuoles in cellular biology.