Question

During an experiment, the same type of bacteria is grown in two petri dishes. Petri dish A has a diameter of 51 mm and has approximately 40,000 bacteria after 1 hour. Petri dish B has a diameter of 75 mm and has approximately 72,000 bacteria after 1 hour. Determine and state which petri dish has the greater population density of bacteria at the end of the first hour.

Answer 1

Answer:

Petri Dish A with a Population density of 19.6 bacteria/mm² has a higher population density at the end of the first hour.

Explanation:

Population density = number of bacteria/area of dish

For Petri dish A

Area of dish = πd²/4 = (22/7) * 51² / 4 = 2043.64 mm²

Population density = 40000 bacteria / 2043.64 mm² = 19.6 bacteria/mm²

For Petri dish B

Area of dish = πd²/4 = (22/7) * 75² / 4 = 4419.64 mm²

Population density = 72000 bacteria / 4419.64 mm = 16.29 bacteria/mm²