Which paper shows a specific color change as the pH of a solution changes?

• A. pH Paper
• B. Petri Dish
• C. Microcentrifuge Tubes
• D. Inoculating Loop

Answer: (A)

The main idea is using a color-changing indicator to read pH. pH paper contains indicators that respond to hydrogen ion concentration, so as the solution’s acidity or basicity changes, the paper shifts color. By comparing that color to a reference chart, you can estimate the pH. The other items are tools or containers used in biology labs and don’t inherently show a pH-dependent color change: a dish for growing cultures, tubes for holding samples, and an instrument for transferring microbes. They won’t indicate pH through color, so they aren’t the right choice.