SvS Biology 2001: 
Charlotte's Web it's not!

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The Search for Better Health (module 9.4)

According to the Board of Studies Syllabus, the purpose and function for studying this unit is summarised by the following statements: (ref: NSW Board of Studies Stage 6 Syllabus, page 53)

Physiological processes proceed without any conscious intervention. Even when something malfunctions, the body tries to repair the damage automatically and unnoticed. The process is the same in all living things and it is only when the process fails to contain the damage that disease can be recognised. Humans have long recognised the symptoms of disease both in themselves and the animals and plants around them. Since the beginnings of recorded history, they have noted the signs that reveal that the body is malfunctioning. Increasing understanding of the causes of disease together with accompanying advances in technology have changed approaches to treatment and management of disease. The search for measures to treat and manage diseases of humans and other organisms continues and this search is paralleled by continued refinements in technology.

All underlined text represents suggested links to information or activities that you should be familiar with and use as a starting point in gaining a knowledge and understanding of this topic.

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1. What is a healthy organism?

• discuss the difficulties of defining the terms health and disease

• outline how the function of genes, mitosis, cell differentiation and specialisation assist in the
  maintenance of health

• process and analyse information from secondary sources and use available evidence to analyse the
  links between gene expression and maintenance and repair of body tissues

        REF: Spectrum of Life, Chapter 7.1

2. Over 3000 years ago the Chinese and Hebrews were advocating cleanliness in food, water and personal hygiene

• distinguish between infectious and non-infectious disease 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

• identify data sources, plan and choose equipment or resources to perform a first-hand investigation using appropriate materials to identify microbes in food or in 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

           REF: Spectrum of Life, Chapter 7.2

3. During the second half of the nineteenth century, the work of Pasteur and Koch stimulated the search for microbes as causes of disease

• describe the role of Pasteur in identifying the causes of disease

• describe the circumstances which resulted in a named micro-organism being identified as the causal agent of a disease of a plant or animal

• outline Koch's postulates and explain how they can be used to identify the causative organism of an infectious disease

• perform an investigation to model or process information to describe Pasteur's classic experiment to identify the role of microbes in decay

• gather and process information to trace the historical development of our understanding of the cause
  and prevention of a disease caused by a micro-organism

  REF: Spectrum of Life, Chapter 7.3

4. Ronald Ross' work on malaria identified insects as vectors of disease

• identify that infectious diseases of animals and plants are caused by pathogens that include:
  prions, viruses, bacteria, protozoans, fungi and macro-parasites

• identify a disease that is transmitted by an insect vector, name the vector and the organism
  infected by the disease

• identify data sources, gather process and analyse information from secondary sources to
  describe the life cycle of one pathogen carried by an insect vector and identify and explain
  when control or prevention of the disease is most effective

• discuss the role of quarantine in preventing the spread of disease and plants and animals into
  Australia or across regions of Australia

• 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

• examine one named infectious disease in detail to describe:
  cause, transmission, host response, major symptoms, treatment, prevention, control

• perform an investigation to examine plant shoots and leaves and gather first-hand information
  of evidence of pathogens, including insect pests, viruses or fungi

• process and analyse information to identify the role of antibiotics in combating bacterial infections

  REF: Spectrum of Life, Chapter 7.4, 7.5, 7.6, 7.7

5. Often we recognise an infection by symptoms it causes. The immune response is not so obvious, until we recover

• identify first line defence barriers to prevent entry of pathogens in
  humans:  skin, mucous membranes, cilia, chemical barriers, other body secretions

• identify antigens as molecules that trigger the immune response

• explain why organ transplants should trigger an immune response

• identify second line defence adaptations, including:
  inflammation response, phagocytosis, macrophage, lymph system, cell death to seal off pathogen

• gather, process and present information from secondary sources to show how one disease results from an imbalance of microflora in humans

  REF: Spectrum of Life, Chapter 7.8, 7.9

6. MacFarlane Burnett's work in the middle of the twentieth century led to a better understanding of the immune response and the effectiveness of immunisation programs

• identify components of the third line of defence as:
  antibodies, T cells, B cells

• describe and explain the immune response in the human body in terms of:
  * interaction between B and T lymphocytes
  * the mechanisms that allow interaction between B and T lymphocytes
  * the range of T lymphocyte types and the difference in their roles

• outline the way in which vaccinations prevent infection 

• 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 small pox, diphtheria and polio

• outline the reasons for the suppression of the immune response in organ transplant patients

  REF: Spectrum of Life, Chapter 7.10, 7.11, 7.12

7. Epidemiological studies involve the collection and careful statistical analysis of large quantities of data. Such studies assist the causal identification of non-infectious diseases

• identify and describe the main features of epidemiology using an identified case study as an example

• gather, process and analyse information to identify the cause and effect relationship of a disease, such as melanoma or lung cancer, the cause of which was identified through careful compilation and analysis of statistics

• identify causes of non-infectious disease using an example from each of the following categories:
  * inherited diseases
  * nutritional deficiencies
  * environmental diseases

• 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

  REF: Spectrum of Life, Chapter 7.13, 7.14

8. Modern knowledge of disease has led to the development of a wide range of strategies to prevent and control disease

• explain how one of the following strategies has controlled and/or prevented disease:
  * public health programs
  * pesticides
  * biological control
  * genetic engineering to produce
  * disease resistant plants and animals

• evaluate the implications of:  genetic resistance of hosts and development of drug resistance in pathogens on the likely spread of disease in the future
• 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

  REF: Spectrum of Life, Chapter 7.15

  
   

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Syllabus Outcomes:

H1     evaluates how major advances in scientific understanding and technology have changed the direction or   nature of scientific thinking
H2    analyses the ways in which models, theories and laws in biology have been tested and validated
H4    assesses the impacts and implications of biology on society and the environment
H6 explains why the biochemical processes associated with cells are related to macroscopic changes in the organism
H8    evaluates the impact of human activity on the interactions of organisms and their environment
H11   justifies the appropriateness of a particular investigation plan
H12  evaluates ways in which accuracy and reliability could be improved in investigations
H13  uses terminology and reporting styles appropriately and successfully to communicate information and understanding
H14  assesses the validity of conclusions from gathered data and information
H15  explains why an investigation is best undertaken individually or by a team
H16  justifies positive values about and attitudes towards both the living and non-living components of the environment, ethical behaviour and a desire for a critical evaluation of the consequences of the applications of science.

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Email me at: vanstriens@knox.nsw.edu.au to post questions

S. van Strien