The Search For Better Health

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The Search For Better Health

• HSC Biology Teacher Workshop
• Monday, 25th September, 2006

Nicole Sherry Ambarvale High School
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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

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Scope Sequence
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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.

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Practical Register
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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.

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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

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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?

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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.

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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-organisms
• Risk
• 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.

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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

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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.

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Secondary Sources

• Sydney Catchment Authority
• http//www.sca.nsw.gov.au
• They will be releasing an on-line activity on
  their
• website Water Quality HSC Chemistry in
• December 2006 (if you dont 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.

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Activity Treatment of Drinking Water

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

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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

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Practical Activity

• 3d. perform an investigation to model Pasteurs
  experiment to identify the role of microbes in
  decay

from Surfing Biology
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9.1 Biology Skills

• 11.2 plan first-hand investigations to
• demonstrate the use of the terms dependent and
  independent to describe variables involved in
  the investigation
• Turn to Prac 9.4.3 Pasteurs 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

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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

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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?

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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
  Kochs work
• 2002 HSC Notes from the Marking Centre Biology

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From the markers

• This question was well answered. Most candidates
  were able to describe Pasteurs 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.

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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

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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 ______________________________
  _____

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4. Immune Response

• 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

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Immune Response

• Animated information about the immune system,
  phagocytosis and lymph nodes is available at
• http//health.howstuffworks.com/adam-200095.htm

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5. MacFarlane Burnet

• a. identify the components of the immune
  response
• - antibodies
• - T cells
• - B cells

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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.

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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.

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• 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.

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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.

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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.

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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.

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• 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.

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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.

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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)

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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

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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

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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

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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

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• 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

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• 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

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• Thankyou
• nicolesherry_at_education.nsw.gov.au