Why must petri dishes be sterilised before use?

Petri dishes must be sterilized before use to eliminate any existing microorganisms that could contaminate the culture and affect experimental results. Contamination can lead to inaccurate data, false conclusions, and compromised research outcomes. Sterilization ensures a controlled environment for the growth of specific microorganisms, allowing for reliable observations and analyses. This process is crucial in microbiology and other scientific fields to maintain the integrity of experiments.