What is an open tube used to hold liquids?

• A. Serological Pipette
• B. Test Tube
• C. Hot Water Bath
• D. Stirring Rod

Answer: (B)

An open tube used to hold liquids is a test tube. Test tubes are small cylindrical containers with an open top, usually made of glass or plastic. They’re designed to hold, mix, and sometimes heat small amounts of liquids during experiments, and the open top allows you to observe what’s happening and add reagents easily. They can be placed in racks and heated directly over a flame or in a water bath, which is common in many procedures.

A serological pipette is meant for transferring precise volumes of liquid, not serving as a container to hold a reaction mixture. A hot water bath is a device used to heat liquids but isn’t itself a container for holding liquids. A stirring rod is used to mix substances, not to hold liquids.