A student inoculates a nutrient agar plate with a sample of Escherichia coli using aseptic techniques. After securing the lid with two pieces of adhesive tape, they place the Petri dish in an incubator at $25∘C25^\circ\text{C}$ in an inverted (upside-down) position for 48 hours.

What is the primary reason for incubating the Petri dish in an inverted position?

To prevent airborne bacteria and fungal spores from settling onto the agar surface through gravity if the lid is slightly loose.

To ensure that gravity pulls the bacterial cells into the agar, allowing them to absorb nutrients from both sides of the colony.

To prevent condensation from forming on the lid and dripping onto the agar surface, which could cause the bacterial colonies to run together and merge.

To facilitate the diffusion of carbon dioxide out of the plate, as it is heavier than air and would otherwise suffocate the culture.

What is the primary reason for incubating the Petri dish in an inverted position?

To prevent airborne bacteria and fungal spores from settling onto the agar surface through gravity if the lid is slightly loose.

To ensure that gravity pulls the bacterial cells into the agar, allowing them to absorb nutrients from both sides of the colony.

To prevent condensation from forming on the lid and dripping onto the agar surface, which could cause the bacterial colonies to run together and merge.

To facilitate the diffusion of carbon dioxide out of the plate, as it is heavier than air and would otherwise suffocate the culture.

Practical skills

Question 13

Markscheme

Practical skills

Question 13

Markscheme

Practical skills

Question 13

Practical skills Questions

Practical skills

Question 13

Practical skills Questions