Module 7 IQ2&3&4

Question 1

Describe the response of an Australian plant to a Pathogen? Provide specific examples.

Answer 1

P.cinnamomi is an introduced species of water mould (filamentous protist) that thrives in Australian conditions. P.cinnamomi has devastated the Eucalyptus Marginata (Jarrah) forests. It lives in the soil, attacking the roots of the Jarrah from which it absorbs its own nutrients. The Jarrah’s damaged roots leave the tree, unable to absorb water and other soil nutrients. Eucalyptus calophylla (marri gum) grows among the Jarrah - it demonstrates resistance to infection by P.cinnamomi.
- The Jarrah suffers from dieback while the marri gum continues to thrive. Jarrah roots reveal lesions while marri gum roots are healthy and thickened –> significantly ˄ lignin development.

Question 2

lignin

Answer 2

A complex molecule found in the xylem component of plant vascular tissue, as well as the woody material of trees. It plays a role in protecting the cellulose cell wall of plant cells from damage by pathogens including forming a physical barrier that is impervious to the pathogen.

Question 3

PAL

Answer 3

An enzyme associated with increased lignin production. It is a feature of stress in some plants.

Question 4

Antigen

Answer 4

An antigen is any substance that causes your immune system to produce antibodies against it. An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also form inside the body.

Question 5

What is adaptive immunity?

Answer 5

Immunity that is acquired throughout your life. It is a specific defence mechanism consisting of specialised cells that act if the pathogen gets past the non-specific defence mechanisms. It involves chemical responses by cells (Third Line of Defence).

Question 6

Outline the physical barriers of first-line defence.

Answer 6

Physical barriers of first-line defence include:

Skin - an outer body covering/ dry outer layer which is difficult to penetrate unless wounded –> it continually sheds to physically remove bacteria from its surface & produces slightly acidic sebum which inhibits microbial growth (contains antimicrobial chemicals)

Cilia - slender hairlike structures that protrude from the surface of most mammalian cells found in nasal passages, ear canal, oesophagus, collecting duct of the kidney –> wave-like movement sweeps foreign material out (expelled out of mouth & nostrils) & keeps passage clear of microorganisms preventing them from colonising.

Peristalsis - muscle movement that occurs in wave-like motions to enable the movement of the oesophagus via muscular contraction -> aids in the movement of secretions (mucus) or foreign invaders into the stomach in order to kill pathogenic organisms.

Question 7

Outline the chemical barriers of first-line defence. (6 barriers)

Answer 7

Chemical barriers of first-line defence include:

Mucous membranes - Contained within epithelial cells lining digestive, reproductive, respiratory and excretory systems –> A viscous slimy secretion released for protection and lubrication

Sebum - has antimicrobial properties and is slightly acidic –> inhibits microbial growth.

Cerumen - Ear wax –> waxy secretions made in ear canal by ceruminous and sebaceous glands located on outer part of canal –> Traps dust & particles.

Lacrimal secretions - Watery fluid containing mucin, lipids, lysozome, immunoglobulins –> produced by tear ducts –> lubricate and protect eye from foreign matter & pathogens

Acidic secretions - low pH –> prevents pathogenic entry by creating hostile env for invaders (produced by vagina, stomach, ear canal, skin)

Lysozymes - Enzyme that aids in the destruction of bacterial cell walls (found in saliva, mucous, tears)

Question 8

Outline the responses of second-line defence.

Answer 8

When pathogens are successful in penetrating the barriers against entry into the organism, non-specific responses that are the ‘second-line of defence’ are quickly activated to try to destroy the invaders before they can cause any damage to the body.
It includes the following responses:
Inflammation
Phagocytosis
The Lymphatic system
Fever
Cell death to seal off the pathogen (granuloma formation)

Question 9

Inflammation

Answer 9

When cells are challenged by pathogens or damaged, they release chemical ‘alarm signals’ such as histamines and prostaglandins. These chemicals cause the following physical responses:

• Capillaries dilate => ˄ blood flow to the site of infection or injury (allows defensive substances into tissue space) => area becomes red, hot and swollen, painful and sometimes less mobile.
• Increases permeability of the blood vessels which allows certain white blood cells to move from the blood into the tissue and attack the invading pathogen
• Phagocyte migration & phagocytosis –> destroys invading microbes
• Tissue repair –> new tissue created to replace dead/damaged cells

Five signs of inflammation:

• Pain
• Heat
• Redness
• Swelling (including swelling of the lymph nodes)
• Loss of function due to pain and swelling

Question 10

Phagocytosis

Answer 10

Phagocytes are white blood cells that can actively move from the blood to the tissues where they ingest and destroy any foreign material including pathogens.

• foreign material is ingested => phagocyte releases enzymes to destroy it. (phagocytosis)
• In acute inflammation (lasting hours or days) the main phagocytes are called neutrophils
• In chronic inflammation (weeks or months) the main phagocytes are called macrophages

Question 11

Lymph system

Answer 11

• The lymphatic system consists of lymph (a milky fluid), lymph nodes, lymph vessels, thymus, spleen tonsils and adenoids.
  Lymph nodes:
• engulf and destroy bacteria and other foreign materials and cell debris circulating through them.
• may become tender when there is an infection nearby
• inflamed and enlarged by the bacteria and toxins they accumulate as they fight the invaders

Question 12

Fever

Answer 12

• Normal body temperature for humans is 37°C which is set by the hypothalamus
• When exposed to pathogens => body releases ‘fever-causing’ chemicals known as pyrogens => alters this set temperature allowing the tissue to heat up.
• Fevers kill or limit the growth of pathogens as most bacteria and viruses grow better at lower temps.

Question 13

Apoptosis

Answer 13

Programmed cell death.
Once tissues is infected by a pathogen, the cells may die to seal off this area of tissue –> infected cells are surrounded by a wall of dead cells to prevent the infection from spreading –> wall of dead cells forms a capsule known as a granuloma –> cells inside granuloma die –> destruction of the pathogens that are infecting them –> debris inside the granuloma is destroyed by macrophages
(e.g bacteria that cause tuberculosis and leprosy typically cause the formation of granulomas)

Question 14

macrophages

Answer 14

A large phagocyte found at the site of tissue inflammation.

Question 15

neutrophils

Answer 15

The most common type of white blood cell, involved in phagocytosis of pathogens and other small particles.

Question 16

eosinophils

Answer 16

Eosinophils are a type of white blood cell. They can build up and cause inflammation. In some conditions, the eosinophils can move outside the bloodstream and build up in organs and tissues.

Question 17

histamines

Answer 17

A nitrogenous compound involved in allergic and inflammatory reactions; causing smooth muscle to contract and capillaries to dialate.

Question 18

Prostaglandin

Answer 18

A hormone secreted by the wall of the uterus to initiate labour; dialates blood vessels and inhibits platelet aggregation.

Question 19

Cytokines

Answer 19

Chemical messengers released by body cells.

Question 20

Other secretions (non-specific)

Answer 20

The body also produces special proteins that assist in the second line of defence.
Interferons - secreted by some cells (such as mast cells) when they are infected with viruses –> cause nearby non-infected cells to produce their own antiviral chemicals, which inhibit the spread of the virus. (non-specific and most effective in short-term viral infections such as colds and influenza.)
The complement system - a group of 20 proteins that circulate in the blood and assist other defence mechanisms –> can be involved in the destruction of pathogens by stimulating phagocytes to become more active, attracting phagocytes to the site of the infection or destroying the membranes of the invading pathogen.

Question 21

Other physical responses to infection

Answer 21

• vomiting and diarrhea
• coughing and sneezing - to expel pathogens that are trapped in mucous
• increased urination - to flush out pathogens
• wound healing (scab formation) - to stop the bleeding, re-establish the barrier and prevent infection

Question 22

Other chemical responses to infection

Answer 22

• Urine - slightly acidic pH - phagocytes such as neutrophils work best in alkaline urine so doctors may prescribe alkalinisers for UTIs
• Cells lining the urinary tract secrete chemicals that help prevent bacteria from binding to these epithelial cells
• Tears - antimicrobial properties

Question 23

How is the adaptive immune system different to the innate immune response? (5 key features)

Answer 23

It is specific
It involves a great diversity of possible responses
It has memory
It is capable of recognising self and non-self
It involves the production of two different types of lymphocytes, B cells and T cells, which are specific to the invading particle.

Question 24

Antigen-Antibody complex

Answer 24

When the appropriate B cells are activated they form plasma cells that produce antibodies, which have an antigen binding site, which match the shape of the antigen they are specific for.
These antibodies then seek out the specific antigen and bind to a part of it, forming the antigen–antibody complex, which causes the deactivation of the antigen by;
- immobilising it
- blocking and neutralising the active binding site of the antigen
- causing the antigen–antibody complex to clump together, making them easier to eliminate by phagocytosis.

Question 25

White Blood cells

Answer 25

• Are much less numerous than red (the ratio between the two is around 1:700)
• Have nuclei
• Participate in protecting the body from infection
  Consist of:
• lymphocytes and monocytes (which become macrophages) with relatively clear cytoplasm, and, 3 types of granulocytes, whose cytoplasm is filled with granules.

Question 26

Antibody

Answer 26

Proteins, called immunoglobulins, which are produced in response to the presence of an antigen in the body.

Question 27

Lymphocyte

Answer 27

One of the five kinds of white blood cells or leukocytes, circulating in the blood –> types include:

• B lymphocytes (often simply called B cells) and
• T lymphocytes (likewise called T cells).

Question 28

B cell

Answer 28

• Recognise and bind antigens, each B cell recognises one specific antigen
• A mature B cell may carry as many as 100 000 antigenic receptors embedded in its surface membrane
• They defend against bacteria and virus’ outside the cell and toxins produced by bacteria.

Question 29

Memory cell

Answer 29

• A type of B cell
• When these cells encounter the same antigen again (even years or decades later), they rapidly differentiate into antibody-producing plasma cells

Question 30

Plasma cell

Answer 30

• A type of B cell
• They secrete antibodies into the blood system
• The antibodies then inactivate the circulating antigens

Question 31

T cell

Answer 31

T cells respond only to antigen fragments that have been processed and presented by infected cells or macrophages (phagocytic cells). They defend against:

• intracellular bacteria and viruses
• protozoa, fungi, flatworms, and roundworms
• Cancerous cells and transplanted foreign tissue

Question 32

Helper T cell

Answer 32

Activates cytotoxic T cells and other helper T cells –> necessary for B cell activation.

Question 33

T cell for delayed hypersensitivity

Answer 33

Protects against pathogens. Causes transplant rejection and inflammation in allergic reactions.

Question 34

Suppressor T cell

Answer 34

Regulates immune response by turning it off when no more antigen is present. - Used for organ transplants –> to suppress the immune system. Suppress T and B cell activity when needed

Question 35

Cytotoxic T cell

Answer 35

Destroys target cells on contact. Recognises tumour (cancer) or virus-infected cells by their surface (antigens and MHC markers).

Question 36

Where do B cells and T cells originate?

Answer 36

Both B and T cells develop from stem cells located in the liver of foetuses and the bone marrow of adults. T cells complete their development in the thymus, whilst the B cells mature in the bone marrow.

Question 37

Humoural immune response

Answer 37

Associated with the serum (non-cellular part of the blood) and involves the action of antibodies secreted by B cell lymphocytes. It protects the body against circulating viruses, and bacteria and their toxins.

Question 38

Cell-mediated immune response

Answer 38

Associated with the production of specialised lymphocytes - T cells. Effective against bacteria and viruses located within the host cells, as well as against parasitic protozoa, fungi and worms. It is also an important defence against cancer.

Question 39

Describe an example of an autoimmune disorder, identifying what happens.

Answer 39

An autoimmune disease is a disease in which the body’s immune system attacks healthy cells, for e.g Coeliac disease. When people with celiac disease eat gluten (a protein found in wheat, rye and barley), their body mounts an immune response that attacks the small intestine. These attacks lead to damage on the villi, small fingerlike projections that line the small intestine, that promote nutrient absorption.

Question 40

MHC

Answer 40

“Major Histocompatibility Complex” - A glycoprotein molecule which acts like an egg-cup to hold an antigen out for inspection by a lymphocyte cell (B & T cell)

Question 41

Draw flowchart of first, second and third line defence (differentiating between the innate and adaptive immune systems)

Answer 41

Check notes

Question 42

Explain how the immune system responds after primary exposure to a pathogen.

Answer 42

Once the antigen has been identified, the appropriate T cells and B cells have to be activated and then it takes time to build up clones of these cells.

• Time is also needed for the cytotoxic T cells to kill the infected cells and for the B cells to produce plasma cells that then secrete antibodies and bind with the antigen to neutralise it.
• If sufficient antibodies are made to destroy all the infecting antigens, the person recovers completely.
• This is known as the primary response
• At the same time, memory T cells and memory B cells specific to the antigen are produced and remain in the body.

Question 43

Explain how the immune system responds when re-exposed to a pathogen.

Answer 43

If the same antigen were to re-enter the body in the future, the response, known as the secondary response, is much quicker.
- After identification of the antigen, the memory cells will activate the production of the cytotoxic T cells and the B cells.
- A very large number of B cells will then form many plasma cells, which secrete a much larger amount of antibodies than in the primary response to destroy the invading antigens before their numbers are large enough to cause any symptoms
The secondary response:
- is more rapid and requires less antigen to initiate it
- produces a much greater quantity of antibodies
- lasts for a longer period of time

Question 44

What is active acquired immunity and how is it induced?

Answer 44

A type of immunity, where the immune response occurs and memory cells are produced. It is naturally induced as the body has to undergo the immune response and suffer the symptoms of the disease in order to develop immunity to it. It can also be artificially induced through the use of vaccines, which cause the production of memory cells without the body experiencing the symptoms of the disease.

Question 45

What is passive acquired immunity and how is it induced?

Answer 45

Passive acquired immunity involves the introduction of antibodies (immunoglobulins) into the body to prevent a disease from developing. These antibodies have been produced by another organism that has suffered the disease.
For e.g,
- Injections containing antibodies are sometimes given to protect travellers to countries where certain diseases are spread (e.g. hepatitis) (This immunity will last for only a couple of months as no memory cells have been produced.)
- Naturally acquired passive immunity occurs during pregnancy, in which certain antibodies are passed from the maternal into the fetal bloodstream.

Question 46

How do hygiene practices help prevent the spread of disease? Provide two examples of personal hygiene practices and two examples of public hygiene practices to illustrate your answer.

Answer 46

Pathogens require the right conditions to continue to survive and proliferate, however, cleanliness and good personal hygiene can limit this growth and transmission.

• Thorough and frequent hand, body and hair washing can prevent the spread of microbes from person to person.
• Ensuring good dental hygiene can prevent the development of mouth infections.
• Avoiding coughing and sneezing on others can help prevent the spread of disease through direct contact.
• Wear PPE such as gloves and face masks when in contact with infected people can prevent the pathogen from entering your body and causing a disease.

Question 47

How does quarantine help prevent the spread of disease? Describe two examples of quarantine practices to illustrate your answer.

Answer 47

Quarantine is a period of isolation to reduce the spread of disease, it prevents people from coming into contact with each other, thus preventing the spread of a pathogen from one person to another.
Examples:
- Inspecting goods in private or commercial travel, with contaminated animals or goods inspected, disinfected, fumigated, isolated or destroyed, preventing indirect contact with these animals or objects, thus preventing the spread of disease.
- Quarantine at airports, border stations and seaports through entry and exit screening, health-alert notifications, public health reporting and physical examinations to prevent the spread of a disease from one state/area/country to another.

Question 48

Describe the process of vaccination and how it prevents the spread of disease, give examples.

Answer 48

Vaccination is the process of making people resistant to infection caused by specific pathogens. They are very effective at preventing future infections. The immunity provided is either active or passive, dependent on the source of the immunity. The vaccine typically contains a live-attenuated or inactivated version of the pathogen, which therefore lead to no symptoms of the disease. This leads to the production of antibodies and T and B memory cells specific to that antigen providing long-term protection from the disease. Live-attenuated examples include the measles virus, mumps, and rubella (MMR) and chickenpox vaccines.

Question 49

What does a public health campaign do? Give an example.

Answer 49

The Government, public health authorities, and non-government organisations organise and distribute public health campaigns to promote the adoption of healthy behaviours. When dealing with an outbreak of infectious disease, campaigns help inform people of the cause of the disease, how it is transmitted and the reasons for the measures employed to control the spread of the disease. For e.g The national COVID-19 campaign aims to reduce the risk to Australians by helping them to; make informed decisions and take up health recommendations (Infectious disease) and the National tobacco campaign for reducing the prevalence of chronic obstructive pulmonary disease, acute myocardial infarction, lung cancer, stroke caused by smoking by changing packaging, advertising quitting services and showing sufferers.

Question 50

Describe an example of how pesticide use has been employed to prevent the spread of disease.

Answer 50

Pesticides (insecticides, herbicides, and fungicides) are chemicals used to prevent the spread of infectious animal and plant pathogens and also insect vectors. Organophosphates are the main class of pesticides used in Australia. They work by disrupting the neurological system of insects. For example, the use of insecticide control used in the control of the female anopheles mosquito. The rapid generation turnover of most pathogens and insect resistance has led to widespread pesticide resistance.

Question 51

Describe an example of how genetic engineering can be employed to prevent the spread of disease.

Answer 51

Genetic engineering is employed to prevent the spread of the zika virus through the genetically modified OX513A mosquitoes, to reduce the population of the Aedes aegypti mosquitoes in the world, thus reducing their ability to spread diseases such as the zika virus. The GM mosquitoes are released into the wild to reproduce with wild mosquitoes and cause their offspring to die. The GM mosquitoes are made by engineering the mosquitoes with two new genes; the lethality gene and the fluorescent marker, by inserting these genes into the genome of mosquito eggs. The lethality gene makes the mosquitoes dependent on the antibiotic tetracycline, which is not available in the wild. The fluorescent marker gene produces a protein that glows red when exposed to light of a certain wavelength, showing scientists which mosquitoes are GM.

Question 52

Assess the effectiveness of antivirals as treatments for the control of infectious disease.

Answer 52

An antiviral is a drug that kills or suppresses a virus’s ability to replicate. The mechanisms by which antivirals act include:

1. Inactivation of virus envelope proteins.
2. Prevention of viral attachment and entry to the host cell.
3. Prevention of viral replication.
4. Prevention of viral protein synthesis.
5. Preventing release of new infectious virus from the host cell.

Advantages:
• Antivirals can be designed to target specific viral pathogens.
• They can significantly improve the health outcomes and life expectancy of infected individuals.

Disadvantages:
• Developing safe and effective antiviral drugs is challenging as viruses use the host cell’s machinery to reproduce, as a result harm can be caused to the host cell.
• The very high mutation rates of viruses = drug-resistance.
• Pharmaceutical companies that develop the antiviral drugs have a monopoly on the market and this is reflected in the drugs cost. For e.g - the antivirals used to treat hepatitis C can cost many tens of thousands of dollars, despite the drug production costing less than $250.
• Antivirals can take years to develop
• Evolution of pathogens can limit their effectiveness
• Bacteria and viruses replicate very quickly, evolve rapidly and spread fast

Question 53

Assess the effectiveness of antibiotics as treatments for the control of infectious disease.

Answer 53

Antibiotics are drugs (natural or synthetic) used to fight bacterial infections. Bactericidal antibiotics kill the bacteria by interfering with the formation of the cell membrane, cell wall or its cell contents, e.g. penicillin.
Bacteriostatic antibiotics stop bacteria from multiplying by interfering with DNA replication, protein production or other cellular metabolic processes, e.g. amoxicillin.

Antibiotics are most effective when;
• They are used solely for the treatment of bacterial infections, not viral infections
• They are used to kill rather than inhibit growth of bacteria
• They are able to get to the site of infection and kill the disease causing bacteria

Advantages:
• The discovery of penicillin rates as one of humanity’s greatest discoveries. Estimates are that 200 million lives have been directly saved from antibiotics.
• Due to different cell structures, e.g. cell walls, bacteria are more easily targeted than viruses.

Disadvantages:
• Antibiotics only work on bacterial infections.
• Misuse and overuse have led to multiple examples of antibiotic resistance.
• People can be allergic to antibiotics.
• There can be side effects, including diarrhea, nausea and upset stomach.

Question 54

Evaluate environmental management and quarantine methods used to control an epidemic or pandemic.

Answer 54

The Ebola epidemic in West Africa was the rapid spread of the Ebola Virus disease transmitted through body fluids such as such as; saliva, blood, vomit, feces and mucus → these must be transmitted through passageways such as the eyes, mouth or nose. Some control measures for this epidemic included;

Environmental control measures:
- Those who die from the disease need to have proper burial or cremation with handlers using protective clothing to prevent contact with bodily fluids as this can be a high risk for disease transmission.

Quarantine control measures:

• All people who have been in contact with infected individuals need to be identified, tested and quarantined if necessary
• Those who have been exposed to the disease need to be quarantined either until they show signs of the disease or are no longer at risk
• Health care workers need to wear protective clothing, e.g. masks, gloves, gowns and goggles covering all exposed skin and an infected person needs to be kept in barrier isolation
• Any equipment, surfaces and patient waste that has had contact with patient body fluids must be disinfected, e.g with chlorine powder, detergents, bleach.

Long term control measures:
- To control the spread of an outbreak, travel history cards ask if a person has visited an affected country, and at the border they are inspected for symptoms.

Question 55

Incidence

Answer 55

The incidence of an infectious disease is the no. of new cases occurring during a specified time (infection rate/probability of contracting the disease). Given by:
(Number of new cases during specified time / size of pop. at start of monitoring period) x 100

Question 56

Prevalence

Answer 56

The prevalence of a disease is the proportion of the population that have the disease at a particular point in time. (prevalence refers to all cases, not just new cases). It is expressed as;
(All new and previous cases during a time period / pop. during the time period) x 100

Question 57

Herd immunity

Answer 57

When an estimated 95% of a population is vaccinated (herd immunity) against a disease there is less of the disease in the community, which makes it harder for the disease to spread.
This is essential to protect individuals who cannot be vaccinated for medical reasons or babies who are too young to yet receive vaccinations.

Question 58

How does mobility affect the incidence and prevalence of diseases?

Answer 58

Humans act as carriers for pathogens and may spread the disease to new locations when they move.

Question 59

Incidence and prevalence of Dengue fever

Answer 59

Dengue fever is a mosquito-borne viral infection found in tropical and subtropical climates worldwide. The disease causes flu-like symptoms and can be potentially lethal (severe dengue). Due to increased urbanisation in these regions approximately half of the
world’s population is now at risk of contracting Dengue fever. The incidence of dengue fever has continued to grow in recent decades. While in part due to
increased diagnosis, the WHO believes the actual number of reported cases is low, with some
estimates suggesting there are 390 million new infections per year.

Question 60

Evaluate a historical strategy to predict and control the spread of disease.

Answer 60

In the Middle Ages there was little hygiene and people had many parasites. Many people believed that disease was caused by bad smells (e.g Black Death) and so they used pleasant scent such as pomander from the french ‘apple of amber’ to try and repel the disease. This strategy was not effective as disease was not caused by “bad smells” but rather by pathogens, which cannot be repelled by scent.

Question 61

Evaluate a culturally diverse example of a strategy to predict and control the spread of disease.

Answer 61

• Traditional Chinese medicine (TCM) involves many strategies, e.g. acupuncture, herbal medicine, maintaining a specific diet, massage and tai chi and qigong practices.
• Ancient Chinese doctors noticed the patterns of some diseases with ‘warm’ diseases which went from one person in a household to another then from street to street and ‘cold damage’ disease.
• Realised that the cause of these warm diseases had no smell, shape or shadow and produced many bitter and cold herbal formulas as treatments.
  These herbal medicines were seen to have some notable antibiotic properties, and thus were not completely ineffective.

Question 62

Evaluate current strategies to predict and control the spread of disease.

Answer 62

• The Aus gov has a National Framework for Communicable Disease Control that was developed with the assistance of the states and territories, available on the gov website. → it considers communicable disease prevention, detection and response with improved organisation and delivery of communicable disease control.
• National Notifiable Diseases Surveillance System → early detection of an outbreak of an infectious disease is registered with this system → Case is investigated and the situation contained as much as possible.
  These strategies are highly effective in the detection, reporting, control and prevention of contagious diseases, as they ensure the outbreak of a disease is recorded and precautions are taken immediately to control its spread.

Question 63

Bush Medicine

Answer 63

Bush medicine refers to the use of Native plants by Aboriginal people for medicine due to the antibacterial and anti-inflammatory properties they contain.

Question 64

Describe the use of three named bush medicines.

Answer 64

Tea tree oil - The tree is endemic to Australia. Indigenous Australians use various parts of the tree to create a paste that contains the oil. It is used as an antiseptic to treat wounds and infections. 
Eucalyptus oil (Eucalyptus sp.) - There are over 700 Eucalyptus species across Australia. Indigenous Australians have long used the oils for their natural antimicrobial and antiseptic properties.
Emu bush (Eremophila glabra) - Indigenous peoples of the Northern Territory used the leaves to make an antiseptic solution that was used to treat wounds. Pharmaceutical companies have found Eremophila glabra has the same antibacterial qualities as established antibiotics. Researchers have proposed using the plant to sterilise artificial joints prior to surgery.

Question 65

What is ‘smoke bush’? Where is it found? What is the traditional Aboriginal use of smoke bush?

Answer 65

Smoke bush (Conospermum stoechadis) is located in South Western Australia, between Geraldton and Esperance. It is a plant that has been used by Aboriginal people for thousands of years for its natural healing properties.

Question 66

Why are Indigenous Australians concerned about the awarding of rights to ‘smoke bush’ species by the WA government to a pharmaceutical company?

Answer 66

Researchers have long been interested in the plant as a potential source of treatment for various diseases, including cancer and HIV. Indigenous people are concerned that they have not received any acknowledgment, financial or otherwise, for their role in discovering the healing properties of smoke bush.

Question 67

Discuss why the development of particular medicines using ‘smoke bush’ from Western Australia shows the need for the recognition and protection of indigenous cultural and intellectual property.

Answer 67

The WA legislation disregards any potential intellectual property rights that Indigenous peoples have on their lands. Multinational drug companies could be sold exclusive rights to entire species of flora, preventing anyone from using these species for any other purposes without the consent of those companies, when it has already been used historically by Indigenous Australians.

Question 68

Describe the range of interrelated factors involved in limiting local, regional and global spread of a named infectious disease.

Answer 68

The swine flu, caused by the influenza virus results in upper, and potentially, lower respiratory tract infections, resulting in symptoms such as nasal secretions, chills, fever, decreased appetite, and possibly lower respiratory tract disease. It is transmitted via Direct person-to-person contact. Some factors involved in limiting the spread of the disease include:

Local: (in USA)
Pig farmers wearing face masks and gloves when dealing with infected animals, vaccinating swine (pigs), Avoiding touching eyes, nose or mouth when near infected people, Washing hands, Disinfecting household surfaces, social distancing/isolation, Shut down of schools, Surveillance for new strains, Quarantine for close contacts, Antiviral drugs made available to susceptible individuals, PPE, Public education programs

Regional: (USA - national response)
social distancing/isolation, Shut down of schools, Yearly flu vaccines for humans, Quarantine for close contacts, Surveillance for new strains.

Global:
Border screening e.g. Using thermal imaging at airports
Travel bans/restrictions, Yearly flu vaccines for humans
Quarantine for close contacts, Surveillance for new strains, Reporting of cases to WHO, Redistribution of antiviral stockpiles to countries lacking antivirals.

Question 69

Why is it necessary to complete the full course of antibiotics when infected by a bacterial infection.

Answer 69

• Necessary in order to minimise build up of resistance to antibiotics by ensuring no bacteria survives
• necessary to maintain effectiveness of the antibiotics against that bacteria in the future.

Question 70

Target cells

Answer 70

Cells that possess receptors for a specific hormone that influences the cells’ activity.