Expert: Walter Hintz - 8/8/2006

Question
expriment:took a steriled petridish and exposed it to any surface,sealed and put in a warm place,no light, for 4 days.bacterias began to grow.what caursed the growth besite the above mensioned conditions?the grown ones are harmfull?so what(to all this questions)?

Answer
Besides warmth and a surface on which to grow bacteria need nutrients.  The agar in the dish contained nutrients.
Most bacteria are not harmful but exposed agar can grow pathogenic (disease causing) germs.
 I do not know how to answer your "so what" question