Final answer:
Cheek cells contain centrosomes and lysosomes, which may not be visible under light microscopy. Centrosomes assist in cell division and lysosomes break down macromolecules with their acidic digestive enzymes.
Step-by-step explanation:
When observing a cheek cell under the microscope, certain organelles may not be visible due to limitations in the resolving power of light microscopy or staining techniques used. Two organelles that are present in cheek cells but may not be visible under these conditions are centrosomes and lysosomes.
Centrosomes are important for cell division and contain a pair of centrioles, which are positioned perpendicular to each other. Although centrosomes have a role in organizing the microtubules that segregate chromosomes during cell division, their exact function in this process is not fully understood.
Lysosomes are membrane-bound organelles that contain digestive enzymes. They are known as the cell's "garbage disposal," as they break down various macromolecules and worn-out organelles. The enzymes within lysosomes operate at a much lower pH than the surrounding cytoplasm, making the internal environment of lysosomes more acidic.