Edexcel GCSE Biology · 1BI0
Specification 5.18B · Paper 1
Revise: Microbial Cultures InvestigationBacteria can grow across nutrient agar in a Petri dish, forming a visible covering. This practical tests whether an antiseptic, antibiotic or plant extract reduces that growth. An antiseptic is used on living surfaces such as skin; an antibiotic is used to treat bacterial infections; and plants produce chemicals that may defend them against pests and pathogens.