Year 10 Health and Disease -Washing Hand Experiment

Hygiene  -HOW CLEAN ARE YOUR HANDS?  (need to leave experiment over the

next 2 or 3 days and record observations).

Download file: Yr10 Diseases Hygiene and hand washing

 

  •  Hygiene-PART (A) -Hand Washing Experiment
  • Watch the videos in PART (B) Hygiene Videos.
  • Hygiene – Part (C) – Research – Different types of pathogens
  • Hygiene – Part (D) – Research  – Food Safety
  • Hygiene- Part (D) – Research – Definitions

Practical work: Washing Hands

HYGIENE  Part A  Hand washing Experiment

Aim: To observe microbe numbers and types from unwashed and washed hands

Materials:    Sterile nutrient agar plates, marking pen, sticky tape

Hand washing (water, soap bar, soap on tap, disinfectant, hand wipes, hand sanitiser, alcohol)

Method:

  1. Collect sterile agar plates (all poured with the same nutrient agar under the same conditions)
  2. Label each petri dish (write information on the base of the agar plate around the edge .
  3. Leave one plate unopened. Seal and label it = CONTROL
  4. For each plate use aseptic techniques to inoculate the plate:
  • – clean bench with alcohol,
  • bunsen burner running, work near bunsen flame,
  • lifting the petri dish lid on angle only, agar facing downwards
  • – to minimise the risk of contamination with microbes from the air)

5. Lightly press fingers onto agar side labelled unwashed, then wash hands with chosen technique

then press fingers onto labelled side washed

6. Seal petri dish with sticky tape (by winding the tape around the edge at the closure point)

and place in the storage tray (with the agar base side upwards

7. Incubate the plate at 300C for 48 hours (this decreases the risk of growing human pathogens)

8. Examine the plate (DO NOT OPEN)

9. Record the number and types of colonies visible through the petri dish lid

10. Collate class results on google drive (to ensure reliability through repetitions for a science experiment. (Due to cost involved, collating results from different groups may be feasible. If resources are available, you may have 5 sets of agar plates per group instead of one set of agar plate).

SAFETY RISK = potential spread of pathogenic organisms

SOLUTION :

1. Incubate at 300C only (not body temperature 370C to minimise chance of growing human pathogens).

2. Ensure plates fully sealed and never reopen (to stop exposure to potential pathogens).

3.  Dispose of plates correctly at end of experiment (all plates placed in a pressure cooker and

exposed to heat and pressure to destroy all microbes before disposal)

Results:

 

 

Hand washing tested

Bacterial colonies (estimation) Fungal colonies (estimation)
Number of different types Total number of colonies present Number of different types Total number of colonies present
Unwashed
Control
Washing method:

·       Water only

·       Soap bar

·       Soap on tap

·       Hand wipes

·       Disinfectant

·       Alcohol

·       Hand sanitiser

Questions

 

  1. Purpose: What do you want to learn?

________________________________________________________________________________________

___________________________________________________________________________________________

  1. Hypothesis: What do you predict will happen?

________________________________________________________________________________________

________________________________________________________________________________________

3(a) List the controlled variables (Controlled variables are quantities that you as a scientist wants to remain constant so that the experiment can be considered as a fair test).

____________________________________________________________________________

b) What is the independent variable? (The variable that is changed to allow comparisons).

___________________________________________________________________________

c) What is the dependent variables? (The variables (things) that you as a scientist focus your

observation on to see how they respond to the changes made to the independent variables).

 

4. Was your hypothesis proved or disproved?___________________________________________________

5.Explain any differences in the bacterial cultures on the hand sanitizer and soap and water agar plates. ­­­

Which is a better method for cleaning your hands?

Differences: ________________________________________________________________________

Better method: _____________________________________________________________________

6.From this experiment, what can you conclude about the effectiveness of hand-washing with soap and

water and using hand sanitizer to reduce the bacteria present on your hands?

 

___________________________________________________________________________________

7.How would you do this experiment differently if you carried it out again?

__________________________________________________________________________________

8.Discussion: Which hand washing method was the most successful? Research why this may be so (hint: look at hygiene control in hospitals)  ____________________________________________________________

 

 

 

 

PART B HYGIENE Videos:  (3 mins)  Growing Bacteria https://www.youtube.com/watch?v=A0b6_kg2oMc

Keep Everything Clean (5 mins)  https://www.youtube.com/watch?v=3FMZbIoPn2w

Spangler Science – Growing Bacteria cool science (5 mins) https://www.youtube.com/watch?v=LSZE6WofLAs

PART C HYGIENE  – RESEARCH – Different types of PATHOGENS  and how to interpret the colonies on the agar plate.

Use the website below to complete all the questions.

https://www.sciencebuddies.org/science-fair-projects/references/interpreting-agar-plates

  1. Complete the table below:
Characteristics used to identify the bacteria/fungi colonies Meaning
Form What is the basic shape of the colony? For example, circular, filamentous
Elevation
Margin
Surface
Opacity
Pigmentation

 

  1. Complete the table below:
Types of pathogen Pictures of colonies on agar plate Description
Bacteria
Fungi (yeast)
Moulds
Other types of pathogens

 

 

Part (D) Hygiene- Research – Food Safety

https://www.rd.com/health/healthy-eating/food-poisoning-food-contamination/

  1. A rare burger might sound juicy and delicious. Should you eat it?
  2. Why should you wash the rock melon as soon as you get home and then store it in the fridge?
  3. You should not leave potato salad outside the fridge for more than 2 hours. Why?

 

 

 

 

 

 

 

Part (E) Research – Micro-organisms that can make you sick.

https://www.mayoclinic.org/diseases-conditions/infectious-diseases/in-depth/germs/ART-20045289?p=1

 

Germs live everywhere. You can find germs (microbes) in the air; on food, plants and animals; in soil and water — on just about every other surface, including your body.

 

Most germs won’t harm you. Your immune system protects you against infectious agents. However, some germs are formidable adversaries because they’re constantly mutating to breach your immune system’s defenses. Knowing how germs work can increase your chances of avoiding infection.

Infectious agents come in a variety of shapes and sizes. Categories include:

  • Bacteria
  • Viruses
  • Fungi
  • Protozoans
  • Helminths

Write definitions  for the above infectious agents.

 

Year 10 Disease – What is ill health and disease?

HYGIENE and SALMONELLA POISONINGS – Research download word document               Yr10_2 Research Hygiene

Research the role of hygiene in preventing food poisoning.

The following sites may help you get started.

http://www.foodauthority.nsw.gov.au/fp/food-poisoning

http://www.foodauthority.nsw.gov.au/ip/legislation

http://www.foodauthority.nsw.gov.au/_Documents/retailfactsheets/health_hygiene_of_food_handlers.pdf

http://tenplay.com.au/news/sydney/2016/1/26/suspected-salmonella-outbreak-at-sylvania-bakery

http://www.smh.com.au/nsw/sylvania-bakery-closed-after-at-least-40-people-suffer-food-poisoning-20160125-gmdwp4.html

  • Describe what is meant by the term food poisoning
  • Complete the following table

Australia’s Most Unwanted

Bacteria Conditions under which these bacteria thrive Food Source Symptoms Prevention
Escherichia coli (E. coli)
Salmonella
Staphylococcus
Listeria
Camphylobacter
Clostridium perfringens
Clostridium botulinum (botulism)

 

  • Identify a recent food poisoning case in Australia. Where? The food involved? The causative organism? Based on your research so far describe one way that this food may have become contaminated.
  • Discuss four food safety rules that apply in Australia include at least one related to storage temperature of food. You may find it easier to present this in a table like the one that follows.
Outline of Food Safety Rule How it minimises contamination risk Have you seen this rule being used in shops? Outline what you saw

 

Year 10 Core B – Topics NSW

ear 10 Topics

 

Year 10 CORE A Year 10 CORE B
Genetics (Biology) Health and Disease (Biology)
Chemical Reactions (Chemistry) Universe (Physics)
Scientific Method

(All Sciences)

Bionics (All Sciences)
Motion (Physics) Forensic Science (All Sciences)
Evolution (Biology)
Climate Science (Earth and Environmental Science)
Reproduction (Biology)

Year 10 Disease

Year 10 Disease – What you will learn

1.Define health and disease.

  • List things that can cause ill health.
  • Relate your personal experiences of health issues/diseases and how do they link to infectious and infectious disease,

2. Distinguish between infectious and non infectious disease.

  • Discuss several examples of each, listing organisms that can cause infectious diseases ie bacteria, viruses, protozoans, fungi, parasites, and prions.
  • Draw diagrams of each of these infectious agents and list distinguishing characteristics of each and a well known example of each including non-human or plant examples
  • Discuss the use of treatments for different types of diseases ie use of antibiotics for bacteria, antifungals for fungal diseases, inability of antibiotics to treat viruses
  • PRAC – Investigate if handwashing/antibacterial sprays are effective in removing bacteria
  • PRAC – Growing Bacteria –
  • Investigate a specific infectious disease including cause, symptoms, treatment
  • Discuss reasons why humans get non-infectious diseases eg lifestyle, genetic, environmental
  • Create a table to show cause and several examples of each cause on non-infectious disease
  • Investigate a specific non-infectious disease including cause, symptoms, treatment

3. Distinguish between infectious and non infectious disease.

  • Discuss the 3 lines of defence that humans have to disease
  • 1st line of defence – barriers eg skin, tears, stomach acid
  • 2nd line of defence – inflammation eg phagocytosis
  • 3rd line of defence – immune system eg antibodies
  • Draw flow chart of what happens in the human body when a pathogen attacks

4. Describe defence mechanisms that humans have to diseases

  • Discuss immunity – natural and vaccine
  • Draw flow chart of what happens in the human body when a pathogen attacks
  • Discuss some issues associated with using vaccination to control disease
  • View and discuss the immunisation schedule for children in Australia

5. In your groups, investigate a recent infectious disease pandemic or non-infectious disease that is of global importance. It can be a human disease (eg Ebola, prostate cancer), or another animal (eg equine influenza, BSE) or plant (citrus canker).

  • It should be a different disease than the one investigated earlier in the course.
  • Students should investigate causes/risk factors, symptoms, mortality, prevention, transmission, control, treatment, distribution, prevalence, current research.
  • Louis Paster – historical events/discovery

Definition of some of these terms will be necessary. The research task can be submitted as a pamphlet, document or powerpoint presentation.

Year 10 Forensic Science

Forensic Science –An overview of Forensic Science Degrees.

Forensic Science Technicians

A simplified guide to forensic Science 

The term forensic science (or forensis, in Latin), which means a public discussion or debate. In the modern context,  forensic applies to courts or the judicial system. Combine that with science, and forensic science means applying scientific methods and processes to solving crimes. Forensic science uses modern technologies to look for scientific evidence in a mixture of scientific fields, tasks, occupations and services, which may include anthropology, ballistics, DNA, chemical (drug) analysis in laboratories, crime scene examination, fingerprints, computer forensics, digital imaging, audio and video analysis. The forensic scientist must have not only the means to analyse chemicals found at the scene and on the suspects but enough knowledge of the uses of the chemicals so that the meaning of finding a chemical somewhere is known.