Effectiveness of disinfectants

This is another practical lesson on comparing the size of clear zones when discs of different disinfectant is applied onto an agar plate with bacteria.

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Question 1

Question 2

Question 3

Question 4

Question 5

Q1.Prokaryotic cells have an extra ring of DNA. What is it called?

Plasmid Plasma DNA ring Genetic ring

1/5

Q2.Why is the agar plate necessary for bacterial culture?

To give bacteria a shelter. To provide bacteria with oxygen. To provide bacteria with mates. To provide bacteria with food.

2/5

Q3.Which TWO of the following is present in prokaryotic cells but not in an eukaryotic animal cell?

Select two (2) boxes

Cell wall Cell membrane Cytoplasm Capsule Mitochondria Flagellum

3/5

Q4.Why is it not a good idea to put the inoculating loop IN the Bunsen flame for 10 seconds?

This is because it will kill too many bacteria. This is because it will put out the Bunsen flame. This is because you may burn yourself. This is because it may melt the inoculating loop.

4/5

Q5.What is binary fission?

It is the process of a prokaryotic cell dividing into 3 genetically identical cells. It is the process of a prokaryotic cell dividing into 2 genetically identical cells. It is the process of a prokaryotic cell dividing into 3 genetically different cells. It is the process of a prokaryotic cell dividing into 2 genetically different cells.

5/5

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Question 1

Question 2

Question 3

Question 4

Question 5

Q1.Prokaryotic cells have an extra ring of DNA. What is it called?

Plasmid Plasma DNA ring Genetic ring

1/5

Q2.Why is the agar plate necessary for bacterial culture?

To give bacteria a shelter. To provide bacteria with oxygen. To provide bacteria with mates. To provide bacteria with food.

2/5

Q3.Which TWO of the following is present in prokaryotic cells but not in an eukaryotic animal cell?

Select two (2) boxes

Cell wall Cell membrane Cytoplasm Capsule Mitochondria Flagellum

3/5

Q4.Why is it not a good idea to put the inoculating loop IN the Bunsen flame for 10 seconds?

This is because it will kill too many bacteria. This is because it will put out the Bunsen flame. This is because you may burn yourself. This is because it may melt the inoculating loop.

4/5

Q5.What is binary fission?

5/5

Video

Play video

Click on the play button to start the video. If your teacher asks you to pause the video and look at the worksheet you should:

Click "Close Video"
Click "Next" to view the activity

Your video will re-appear on the next page, and will stay paused in the right place.

Worksheet

PDF

PPTX

Google

These slides will take you through some tasks for the lesson. If you need to re-play the video, click the ‘Resume Video’ icon. If you are asked to add answers to the slides, first download or print out the worksheet. Once you have finished all the tasks, click ‘Next’ below.

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Effectiveness of disinfectants

This quiz will assess you on your understanding in working scientifically, antibiotic resistance and aseptic techniques.

Question 1

Question 2

Question 3

Question 4

Question 5

Q1.What is a hypothesis?

A prediction that must be correct. A prediction that must be wrong. A question that you ask as a scientist. A predication that can be tested.

1/5

Q2.In the practical of testing the effectiveness of different types of disinfectants, what was the dependent variable?

The different types of disinfectant. The time of cutting out the paper discs. The size of the clear zones. The size of the paper discs.

2/5

Q3.In the practical of testing the effectiveness of different types of disinfectants, what was the control variable?

The different types of disinfectant. The time of cutting out the paper discs. The size of the clear zones. The size of the paper discs.

3/5

Q4.What does aseptic mean?

Free from bacteria. Free from viruses. Free from microbes. Free from antibiotic resistance.

4/5

Q5.Calculate the area of a clear zone with a 4 mm radius. Take π as 3.14. Correct your answer to 3 significant figures.

0.251 mm² 0.504 mm² 25.1 mm² 50.2 mm²

5/5

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Effectiveness of disinfectants

This quiz will assess you on your understanding in working scientifically, antibiotic resistance and aseptic techniques.

Question 1

Question 2

Question 3

Question 4

Question 5

Q1.What is a hypothesis?

A prediction that must be correct. A prediction that must be wrong. A question that you ask as a scientist. A predication that can be tested.

1/5

Q2.In the practical of testing the effectiveness of different types of disinfectants, what was the dependent variable?

The different types of disinfectant. The time of cutting out the paper discs. The size of the clear zones. The size of the paper discs.

2/5

Q3.In the practical of testing the effectiveness of different types of disinfectants, what was the control variable?

The different types of disinfectant. The time of cutting out the paper discs. The size of the clear zones. The size of the paper discs.

3/5

Q4.What does aseptic mean?

Free from bacteria. Free from viruses. Free from microbes. Free from antibiotic resistance.

4/5

Q5.Calculate the area of a clear zone with a 4 mm radius. Take π as 3.14. Correct your answer to 3 significant figures.

0.251 mm² 0.504 mm² 25.1 mm² 50.2 mm²

5/5

Lesson summary: Effectiveness of disinfectants

It looks like you have not completed one of the quizzes.

To share your results with your teacher please complete one of the quizzes.

The next lesson in Cell biology is "Stem cells and the use of stem cells"

Browse Oak's lessons:

Subjects Schedule