The Search For Better Health

HSC Biology Teacher Workshop

Monday, 25th September, 2006

Nicole Sherry

Ambarvale High School

Course Requirements

Biology Syllabus p.10

The HSC course incorporates the study of:a) the core, which constitutes 90 indicative hours and includes:• Maintaining a Balance (30 indicative hours)• Blueprint of Life (30 indicative hours)• The Search for Better Health (30 indicative hours)

b) ONE option, which constitutes 30 indicative hours and may comprise any one of the following:

• Communication• Biotechnology• Genetics: The Code Broken?• The Human Story• Biochemistry

Scope & SequenceLesso

nPre-readin

g

Topic Homework Syllabus Referenc

e

Register

1.1 H pp 336-338 What is a healthy organism Q p339 1a,b,c

1.2 H pp 340-343 Prac 9.4.1: Identifying microorganisms

Write up practical 2a,b,c,d

1.3 Continued Write up practical

1.4 H pp 346-347 Prac 9.4.2: Treatment of drinking water

Answers to practical questions, Q p347-348

2e

1.5 H pp 349-351 Prac 9.4.3: Pasteur Experiment Write up practical 3a,d

1.6 H p 360 Prac 9.4.4 Malaria Q p353 3e

1.7 H p 362 Prac 9.4.6:Antibiotics (P.M Activity 7.9)

Answer questions to P.M

3c,g

Practical Hours

Biology Syllabus p. 9

Practical experiences are an essential component of both the Preliminary and HSC courses. Students will complete 80 indicative hours of practical/field work during both the Preliminary and HSC courses with no less than 35 indicative hours of practical experiences in the HSC course. Practical experiences must include at least one open-ended investigation integrating skill and knowledge outcomes in both the Preliminary and HSC courses.

We need to include at least 10 hours practical experiences in this unit.

Practical RegisterPractical

No.Title Syllabus outcome No. Hours Date

completed

9.4.1 Identify microbes in food or in water 2d 1

9.4.2 Treatment of Drinking Water 2e 1

9.4.3 Pasteur’s Experiment 3d 1

9.4.4 Malaria 3e 1

9.4.5 Research an Infectious Disease 3f 2

9.4.6 Antiobiotic Resistance 3g 1

9.4.10 Plant Diseases 7c 1

TOTAL 12hours

1. What is a healthy organism? Discuss the difficulties in defining the terms ‘health’ and ‘disease’

- definition for health

- definition for disease

- difficulties associated with these definitions

Outline how the function of genes, mitosis, cell differentiation and specialisation assist in the maintenance of health.

Use available evidence to analyse the links between gene expression and maintenance and repair of body tissues.

2. Cleanliness in food, water & personal hygiene.

distinguish between infectious and non-infectious disease - definition for infectious- definition for non-infectious

explain why cleanliness in food, water and personal hygiene practices assist in control of disease

identify the conditions under which an organism is described as a pathogen

Practical Activity

2d. identify data sources, plan and choose equipment or resources to perform a first-hand investigation to identify microbes in food or in water

Which outcomes from 9.1 Biology skills can be met during this experiment?

9.1 Biology Skills

During the practical you can meet outcomes 9.1 Biology Skills:

11.3 choose equipment or resources by:a) identifying and/or setting up the most appropriate

equipment or combination of equipment needed to undertake the investigation

1. Using agar plates to culture bacteria and fungi. Placing food or water samples on the agar and incubating for a couple of days.

2. Moistening a piece of bread in a petri dish and leaving in a warm location if you do not have an incubator.

Biology Skills

11.3 b) carrying out a risk assessment of intended experimental procedures and identifying and addressing potential hazards

Risk Assessment:Activity:

Growing micro-organismsRisk:

micro-organisms may be harmful. Precautions:

Seal the petri dish with sticky tape and clearly label the date and what the sample is. After the experiment the micro-organisms will need to be destroyed before discarding if using plastic petri dishes. If using glass petri dishes they will need to be sterilised before reusing.

9.1 Biology Skills

12.1 perform first-hand investigations by:

c)disposing carefully and safely of any waste materials produced during the investigation

d) identifying and using safe work practices during investigations

2d. Treatment of Drinking Water

Gather, process and analyse information from secondary sources to

- Describe ways in which drinking water can be treated and use available evidence to

- Explain how these methods reduce the risk of infection from pathogens.

Secondary Sources Sydney Catchment Authorityhttp://www.sca.nsw.gov.auThey will be releasing an on-line activity on their website – “Water Quality: HSC Chemistry” in December 2006 (if you don’t already have the CD)

Sydney Water http://www.sydneywater.com.au

Water Made Clear: A consumers guide to accompany the Australian Drinking water Guidelines 2004.

Activity: Treatment of Drinking Water

Scan through “Water Made Clear” and complete the table on the front.

3. Pasteur & Koch 3a. describe the contribution of Pasteur and Koch to our

understanding of infectious diseases

3b. distinguish between:– prions– viruses– bacteria– protozoans– fungi– macro-parasites

and name one example of a disease caused by each type of pathogen

Practical Activity

3d. perform an investigation to model Pasteur’s experiment to identify the role of microbes in decay

from Surfing Biology

9.1 Biology Skills

11.2 plan first-hand investigations to:

a) demonstrate the use of the terms ‘dependent’ and ‘independent’ to describe variables involved in the investigation

Turn to Prac 9.4.3 – Pasteur’s Experiment & complete

Independent Variable:

(what we are manipulating) air can re-enter/not re-enter

Dependent variable:

(what we are measuring) presence of microbes, decay

9.1 Biology Skills

b) identify variables that need to be kept constant, develop strategies to ensure that these variables are kept constant and demonstrate the use of a control

Variables that need to be kept constant:

Amount of water, amount of heating, amount of broth.

Use of a control:

Leave one flask untreated

Exam Questions

Question 27 (8 marks)Evaluate the contributions made by both Louis Pasteur and Robert Koch to our present understanding of the causes and possible prevention of infectious diseases.

Evaluate: Make a judgement based on criteria

What things should be included in this for an 8 mark answer?

For the full 8 marks students are required to:

Describe the work of Koch and Pasteur

Relate these to our present understanding of both the cause and possible methods of prevention of disease caused by micro-organisms.

Include a judgement of the impact of Pasteur and Koch’s work

2002 HSC Notes from the Marking Centre Biology

From the markers:

This question was well answered. Most candidates were able to describe Pasteur’s experiment and Koch's postulates.

Candidates were also able to evaluate, but many wrote more than required and went beyond the space suggested in the answer booklet. (a full page of 25 lines was given)

There was a small number of candidates who found it difficult to relate the work of these scientists to modern practices. This was particularly so for Koch.

A small number of candidates did not discuss the scientists separately.

The best responses included a judgement about the scientists' work as part of their evaluation.

Infectious Disease

3f. identify data sources, gather process and analyse information from secondary sources to describe one named infectious disease in terms of its:

- cause- transmission- host response- major symptoms- treatment- prevention- control

Exam Question 2005 HSC exam

Question 19 (4 marks)

During your study of Biology you have been required to gather and

analyse information on an infectious disease.

Fill in the table below for ONE infectious disease.

Name of the disease ___________________________________

Feature Description

Cause

Symptom

Treatment

Prevention

a. identify defence barriers to prevent entry of pathogens in humans:- skin- mucous membranes- cilia- chemical barriers- other body secretions b. identify antigens as molecules that trigger the immune response c. explain why organ transplants should trigger an immune response d. identify defence adaptations, including:- inflammation response- phagocytosis- lymph system- cell death to seal off pathogen

4. Immune Response

Immune Response

Animated information about the immune system, phagocytosis and lymph nodes is available at:

http://health.howstuffworks.com/adam-200095.htm

5. MacFarlane Burnet

a. identify the components of the immune response:

- antibodies

- T cells

- B cells

Non-Specific Immunity The best action against micro-organisms is to prevent their entry into the body

altogether This first line of defence against infection takes place at the body surfaces. Skin - dry, waterproof surface that limits bacterial growth and prevents

the entry of other pathogens. Mucous membranes & cilia

- mucus secreted by the cells lining your respiratory tract traps bacteria which are then swept up to the back of the throat by the action of cilia which line much of the tract. - the mucus may be swallowed, blown, coughed or sneezed out.

Chemical Barriers- acidity of the stomach

Other body secretions- tears & saliva contain lysozyme which causes bacteria to lyse or

burst.- glands in skin secrete fatty acids and sweat contains salt, both of which inhibit bacteria.

Components of the Immune System Bone marrow, the soft tissue in the hollow

centre of bones produces stem cells that become each type of blood cell.

Lymphoid cells either mature in the - bone marrow to become –B lymphocytes (B cells) or- thymus to become – T lymphocytes (T cells)

Monocytes, macrophages, and neutrophils are often referred to collectively as "phagocytes."

These scavenger cells engulf and destroy some invading particles, and clean up the remains of others that have been destroyed by T-cells or B-cells.

Lymphocytes can travel in the blood vessels or in the lymphatic vessels.

Cells are exchanged between blood and lymphatic vessels.

The organs of the immune system are positioned throughout the body.

They are called lymphoid organs because they are home to lymphocytes.

Lymphatic system monitors the body for invading microbes.

Lymphatic vessels carry lymph, a clear fluid.

Lymph Nodes are found along the lymphatic vessels, with clusters in the neck, armpits, abdomen and groin.

Removal of lymph nodes: Breast cancer cells which break off from the tumor frequently travel through the lymph fluid to the lymph nodes where they get trapped.

Immune Cells

Immune system stockpiles a huge arsenal of cells.

Some immune cells take on all comers, while others are trained on highly specific targets.

To work effectively they all work cooperatively.

Sometimes immune cells communicate by direct physical contact,

Sometimes by releasing chemical messengers.

Inflammation Response Arterioles in the area around a cut dilate, resulting in an

increased blood supply to the area. The blood carries phagocytes to the area. Phagocytes that arrive early release chemicals such as

histamine that attract more phagocytes to the infection. The pathogen is killed and engulfed by the phagocytes,

material that has leaked from the capillaries will form a clot around the infection and prevent its spread.

Pus is formed from dead white blood cells and other cell debris.

Eventually the pus and other dead or damaged cells are reabsorbed by other cells of the body or released from the skin.

T Lymphocytes (T-Cells) Viruses, parasites and bacteria that

invade the body are composed of cells.

On the surface of each cell are genetic markers called "antigens."

The immune system knows which antigens belong in a person's body and which do not.

When "helper" T-cells spot a foreign antigen in the body, they stimulate the production of

"killer" T-cells, which engulf and destroy the invading cell.

"Suppressor" T-cells shut down the immune system attack once the foreign cell is destroyed.

Helper T-cells can also order the second type of lymphocytes-B-cells- into action.

Helper T-cells point out foreign antigens to the B-cells which, in turn, replicate rapidly to produce a large number of plasma cells which produce a Y-shaped protein called an “immunoglobulin" or "antibody."

The antibody zeroes in on the antigen and attaches to the surface of the invading cell.

The antibody then summons the ''complement system"-a group of proteins circulating in the bloodstream-to surround the cell and dissolve a hole in it.

This process is called cell lysis.

Antibodies Over the course of a lifetime, millions of antibodies are produced by B-cells.

The immunoglobulins of each B cell have a specific structure and recognise only one kind of antigen.

Once an antibody has been produced, it circulates through the body for many years, making the body "immune" to further attacks by that particular antigen.

Some of the B cells produced differentiate into B-memory cells.

Plasma cells only last a couple of days.

Memory cells can survive for years or for life.

Organ Transplants

5d. outline the reasons for the suppression of the immune response in organ transplant patients

ABC Catalyst – Transplant Hope New Scientist – Boldest Cut (29 May 04)

Vaccination Programs

5c. outline the way in which vaccinations prevent infection

5e. process, analyse and present information from secondary sources to evaluate the effectiveness of vaccination programs in preventing the spread and occurrence of once common diseases, including smallpox, diphtheria and polio

6. Epidemiology

6a. identify and describe the main features of epidemiology using lung cancer as an example

6c. gather, process and analyse information to identify the cause and effect relationship of smoking and lung cancer

Non-Infectious Diseases 6b. identify causes of non-infectious disease using an

example from each of the following categories:- inherited diseases- nutritional deficiencies- environmental diseases

6d. identify data sources, plan and perform a first-hand investigation or gather information from secondary sources to analyse and present information about the

- occurrence, - symptoms, - cause, - treatment/management of a named non-infectious disease

7. Quarantine 7a. discuss the role of quarantine in preventing the

spread of disease and plants and animals into Australia or across regions of Australia

7d. process and analyse information from secondary sources to evaluate the effectiveness of quarantine in preventing the spread of plant and animal disease into Australia or across regions of Australia

www.aqis.gov.au ABC Catalyst – AQIS

7b. explain how ONE of the following strategies has controlled and/or prevented disease:

- public health programs

- pesticides

- genetic engineering to produce disease-resistant plants and animals

7e. gather and process information and use available evidence to discuss the changing methods of dealing with plant and animal diseases, including the shift in emphasis from treatment and control to management or prevention of disease

Thankyou

nicolesherry@education.nsw.gov.au