Applications of Indigenous Knowledge and Biotechnology (Grade 10 NSC Matric Life Sciences): Revision Notes
Applications of Indigenous Knowledge and Biotechnology
Traditional medicines
Traditional medicine plays a significant role in healthcare systems worldwide. According to the World Health Organisation, traditional medicine incorporates plant and animal product-based therapies as well as spiritual practices. Up to 80% of people in African and Asian countries rely on traditional medicines for their basic health care needs.
Traditional medicine systems have been developed over thousands of years and represent accumulated knowledge passed down through generations. This indigenous knowledge forms the foundation of primary healthcare for billions of people worldwide.
In South Africa, there are broadly two types of traditional medicine practitioners: herbalists and diviners. Herbalists use plants to prescribe remedies for various ailments. Diviners are believed to communicate with ancestral spirits to diagnose problems and ailments. Traditional healers rely on up to 4000 different plants for remedies. For example, Pygneum, a traditional medicine, has been used in Africa and elsewhere to treat early forms of cancer.
Due to the high cost of modern Western health care systems and technologies, there has been increased focus on researching African traditional remedies and medicines. Traditional African medicine may have healing properties that have been recognised through generations of use and passed down through cultural systems. Because of the potential to reach greater masses at lower cost, there have been attempts to combine traditional African medicine with modern health care systems.
Integration Example: KwaZulu-Natal Hospital
A 48-bed hospital opened in KwaZulu-Natal, South Africa, in 2010, demonstrating successful integration of traditional and modern medicine. This hospital treats patients using a combination of traditional methods and Western healing approaches, providing accessible healthcare that respects cultural practices while maintaining medical standards.
Modern biotechnology
Modern biotechnology has revolutionised medicine through scientific research based on reproducible investigations. Five key achievements of modern medicine demonstrate how biotechnology has transformed healthcare and treatment options.
1. Immunity and vaccines
Immunity refers to the body's resistance to infection by bacteria and viruses. The human body can be infected by numerous microorganisms including bacteria, protozoa, viruses and fungi. Our bodies have developed a range of defence mechanisms against these infections.
The body defends itself against infection through various barriers:
- Physical barriers include the skin, saliva, tears and mucus. They also include tiny hairs in the lining of the respiratory tract known as cilia.
- Chemical barriers include various allergic responses that result in inflammation or swelling. These responses are caused by the body's chemical defence system releasing chemicals to attack foreign objects entering the body. White blood cells known as eosinophils are normally responsible for allergic responses.
- Cellular mechanisms work to fight bacterial infections. These include neutrophils, macrophages and other white blood cells which attack pathogens and destroy them through a process called phagocytosis.
The defence mechanisms described above form part of the innate immune system - our body's first line of defence that responds quickly to any threat. This system provides immediate but general protection against pathogens.
The body also has an adaptive immune system which 'remembers' each pathogen that invades the body based on specific markers called antigens. When a foreign organism invades, the adaptive immune system launches an antigen-specific response which destroys the infectious agent.
Vaccination is the most effective method of preventing infectious diseases. It has led to the eradication of smallpox throughout the world and has greatly reduced diseases such as polio, measles and tetanus.
How Vaccination Works
Step 1: Inject components of an infectious agent in a non-toxic form
Step 2: Individual's adaptive immune system recognises the vaccine
Step 3: Immune response produces memory cells specific to that pathogen
Step 4: When repeat infection occurs, memory cells mount an effective and rapid immune response
2. Antibiotics
Antibiotics represent another major biotechnological advance in medicine. Antibiotics stop or inhibit the growth of disease-producing bacteria. These substances were originally found in organisms such as fungi and can now be chemically manufactured.
Antibiotics can be administered to patients through multiple methods including injections, tablets, syrups, or suspension forms, allowing for flexible treatment approaches based on patient needs and condition severity.
3. Blood transfusions
Blood transfusions often save the lives of people who have lost large amounts of blood due to trauma from accidents and surgery. Before a person receives blood from a donor, the blood must be typed to ensure the donor is compatible with the recipient.
Blood compatibility is critical - receiving incompatible blood can cause dangerous immune reactions that may be life-threatening. Both ABO blood groups and Rhesus factors must be carefully matched.
Blood is classified based on the presence of antigens in the red blood cells. An antigen is a molecule recognised by the immune system. There are four different types of blood groups, and recipients can only receive blood that is compatible with their own blood type.
The ABO blood group system works as follows:
- Blood Group A has antigen A only
- Blood Group B has antigen B only
- Blood Group AB has both antigen A and B
- Blood Group O has neither antigen A or B
| Blood group | Blood donor (person giving blood) | Blood recipient (person requiring blood) |
|---|---|---|
| A | A and AB | A and O |
| B | B and AB | B and O |
| AB | AB only | All groups |
| O | All groups | O only |
Blood Compatibility Memory Aid
Remember: Group O can give to all groups (universal donor), while Group AB can receive from all groups (universal recipient).
For Rhesus factor: Approximately 85% of the population is Rhesus positive, while 15% are Rhesus negative.
The Rhesus factor must also be considered for both recipient and donor. The Rhesus factor is another type of antigen found on the surface of red blood cells. Blood group compatibility ensures that recipients receive blood from donors that match both their ABO blood group and Rhesus factor, preventing dangerous immune reactions.
4. Cloning
Cloning is the process by which a genetically identical copy of an organism is produced. In nature, cloning occurs when organisms such as plants, insects or bacteria reproduce asexually. The copied material is referred to as a clone.
There are three main types of cloning:
- Gene cloning involves cloning small sections or regions of DNA
- Reproductive cloning produces copies of whole animals or cells
- Therapeutic cloning produces stem cells for experiments to attempt to replace injured or diseased tissues
Some plants have been producing identical clones of themselves through natural processes for millions of years. Through the production of 'runners' (stolon), strawberry crops produce genetically identical offspring. Similar cloning occurs in grasses, potato crops and onions.
Artificial cloning occurs through either vegetative propagation or tissue propagation. Propagation is the process by which existing organisms produce more offspring.
Vegetative Propagation Process
Step 1: Take a leaf cutting from a plant
Step 2: Unspecialised cells called callus begin to grow and divide
Step 3: Callus cells form various specialised cells such as roots and stems
Step 4: A complete grown plant develops, genetically identical to the original
Tissue culture propagation is a more recent practice involving taking pieces of specialised roots, isolating the cells and growing them in a nutrient-rich culture. In the culture, the specialised cells become transformed into undifferentiated cells similar to the calluses mentioned above. The calluses are then treated with chemicals that trigger the growth of new plants identical to the original plant.
Reproductive Cloning Process
The technique used to clone whole animals involves removing a nucleus from a somatic cell (any non-reproductive body cell containing both sets of chromosomes). This nucleus is then added to a recipient egg cell that has had its nucleus removed (denucleated cell). The resulting clone can be transferred to a surrogate mother for development.
5. Stem cell research
Stem cells are cells found in all multicellular organisms. Stem cells can differentiate into any type of cell such as a red blood cell, nerve cell or muscle cell. The two types of stem cells are embryonic stem cells and adult stem cells. Embryonic stem cells can specialise into any cell type, while adult stem cells usually have some restrictions regarding what type of cell they can become.
Adult stem cells are produced in various tissues including the liver and bone marrow. Embryonic stem cells are found in the womb of pregnant animals and can be created in laboratories through fertilisation methods.
The potential uses for stem cells include treating spinal cord injuries by repairing damaged nerve tissue, addressing brain damage by replacing neurons in conditions like Parkinson's disease, treating cancer through bone marrow transplants, and providing new skin cells for burn victims.
Ethical issues and legislation
The use of stem cells, particularly embryonic stem cells, is highly controversial. Many people oppose it for moral, religious or philosophical reasons, largely based on concerns about what happens to unused embryos after research.
Key ethical questions include:
- What should be done with fused cells (embryos) that are not used for therapeutic or reproductive purposes?
- Are we favouring certain genetic types over others when selecting for reproduction using cloning?
- Should private companies conducting cloning research be required to share benefits with the public?
- Do cloned human embryos have the same rights as normal human beings?
- Are there better alternatives to stem cell research?
Different countries have varying laws governing stem cell research. Some European countries such as Finland, Sweden, Belgium, Greece, Britain, Denmark and Netherlands allow stem cell research using human embryos, while others such as Germany, Austria, Ireland, Italy and Portugal do not. The United States has divided opinions, with some states providing funding while others do not. Countries like India, Iran, South Korea, China and Australia are supportive of stem cell research, while South Africa continues to support stem cell research.
Key Points to Remember:
- Traditional medicine incorporates indigenous knowledge and plant-based therapies, with up to 80% of people in African and Asian countries relying on these approaches for basic healthcare
- Modern biotechnology has revolutionised medicine through five key areas: immunity and vaccines, antibiotics, blood transfusions, cloning, and stem cell research
- The immune system uses physical, chemical and cellular barriers to defend against infection, with vaccines training the adaptive immune system to remember and fight specific pathogens
- Blood transfusions require careful matching of ABO blood groups and Rhesus factors to ensure compatibility between donors and recipients
- Cloning can be natural (like plant runners) or artificial (through vegetative or tissue culture propagation), with applications ranging from agriculture to medical research
- Stem cell research offers potential treatments for spinal cord injuries, brain damage, cancer and burns, but raises important ethical questions about the use of embryonic cells