Required Practical 6 Flashcards
(19 cards)
What does the action of the disinfectant do to bacteria?
Kills the bacteria.
What happens if the clear zone is too large?
The clear zone could be too large or overlap with others.
What must be the same for a fair test?
The discs must be the same size.
What material property must be the same in the experiment?
The material or absorbency of the discs.
How long should the discs be in solution?
They should be in the solution for the same time period.
What process do bacteria use to reproduce?
Binary fission.
What is one precaution to prevent contamination?
Keep the lid on the Petri dish.
Why should the lid of the Petri dish be kept closed?
To prevent unwanted bacteria from contaminating the dish.
Why wear gloves in the lab?
To prevent contamination from bacteria on your hands.
How should you handle bacterial cultures to prevent contamination?
Use a sterile pipette or flame the loop.
Which substance is tested in the experiment?
Cinnamon.
Which substance is the most effective at 4°C?
Thyme is the most effective at 4°C.
Which substances have the same effectiveness at 4°C and 35°C?
Clove and cinnamon.
Which substances are less effective at 4°C than 35°C?
Bay and nutmeg.
What happens at lower temperatures regarding molecular movement?
Less kinetic energy or less movement of oil or phospholipid molecules.
Why must the bacteria be sterilized before the experiment?
To prevent contamination or ensure the same number of bacteria are transferred.
How do you express 6 million in scientific notation?
6 × 10⁶.
What is another acceptable answer for 6 million?
6,000,000.
What should be done for more reliable results?
Repeat the measurements for each value.
