Final answer:
In the analogy, the liquid part of the salad dressing represents the cytoplasm of a cell, while the particles symbolize the organelles within the cytoplasm.
Step-by-step explanation:
When comparing a spoonful of Cathy's favorite salad dressing to a cell, the liquid would be equivalent to the cytoplasm and the particles of salt, pepper, and garlic would be equivalent to the organelles. The cytoplasm is the entire region of a cell between the plasma membrane and the nuclear envelope, which includes the gel-like cytosol and various organelles suspended within it. The liquid part of the cytoplasm, known as the cytosol, is made up of about 80 percent water and contains dissolved substances necessary for cellular life, such as salts, sugars, and proteins.