Part 3: The Work of Semmelweis

Question 1

Why was it difficult for Semmelweis to convince others to accept his ideas?

Answer 1

People did not pay attention to him as he wasn’t from the upper class.

Question 2

What other discoveries were made, and by whom, in the mid- to late- 19th century? (3)

Answer 2

1. Louis Pasteur showed that microorganisms cause disease; he developed vaccines against diseases such as anthrax and rabies.
2. Joseph Lister started to use antiseptic chemicals to destroy pathogens before they caused infection in operating theatres.
3. As microscopes improved, it became possible to see pathogens.

Question 3

Describe a method for showing the effect of washing your hands. (6)
Equipment:
• Agar plate
• Ruler
• Sterile swabs
• Agar jelly
• Tape
• Access to disinfectant and antibacterial soap
• Marker pen

Answer 3

1. Put the agar plate upside down, so the lid is beneath.
2. Use a ruler to draw line on the plate down into two halves- label one side W (washed) and the other side UW (unwashed)
3. One person should wash their hands and the other shouldn’t.
4. Both people swab their hands using a sterile swab and gently rub the jelly on the correct side of the plate.
5. Dispose of the swabs in disinfectant
6. Secure the lid with tape

Question 4

State the independent variable for showing the effect of washing your hands

Answer 4

Whether your hands are washed or not

Question 5

State the dependent variable for showing the effect of washing your hands.

Answer 5

Zones of inhibition

Question 6

State the control variables for showing the effect of washing your hands. (2)

Answer 6

1. Swabbing hands for the same length of time
2. Keeping plates at the same temperature