Final answer:
The statement is true; biologists use a burner, often a Bunsen burner, to sterilize tools such as inoculating loops or needles in order to maintain an aseptic environment when transferring bacterial colonies from one agar plate to another, ensuring pure cultures.
Step-by-step explanation:
The statement that biologists may light a burner to sterilize tools used to transfer bacterial colonies from one agar plate to another is true. Sterilization of tools is a critical step in aseptic techniques to prevent contamination of bacterial cultures. Tools like inoculating loops, needles, and pipettes are sterilized using direct heat from a flame, usually a Bunsen burner, or by first dipping them in alcohol then passing briefly through the flame to evaporate the alcohol. This process is essential to ensure that each bacterial colony transferred is pure and not contaminated by other microbes.
Moreover, when using solid media like an agar plate, the surface contains individual colonies which are clones of single bacteria cells. When a single colony is transferred to new media, it is anticipated to grow as a pure culture, further stressing the importance of starting with sterilized tools. Standardized laboratory protocols, such as flame-sterilization of metal tools or moist-heat sterilization methods like autoclaving, are employed to maintain an aseptic environment.