Biology and Human Welfare
Biology and Human Welfare is a critical area of study that focuses on the relationship between biological knowledge and its practical applications to improve human health, agriculture, environment, and overall well-being. By understanding the biological processes that govern life, we can enhance the quality of life, solve health problems, increase food security, and promote sustainable environmental practices.
1.0Human Health and Disease
Health → State of complete physical, mental and social well-being. (W.H.O.)
Disease : When the functioning of one or more organs or systems of the body is adversely affected. Characterised by sign and symptoms.
Bacterial Disease- Dysentery, plague, diphtheria, Tetanus, tuberculosis, whooping cough, cholera.
Viral Disease - Polio, influenza, measles, chicken pox, Mumps, Rabies, Swine flu, Covid-19, SARS (Severe acute respiratory syndrome)
Protozoan Disease- Malaria
Helminthic Disease
Fungal Disease
Prevention And Control of Disease
- Personal Hygiene
- Public Hygiene
- Control of disease-causing agents
Immunity : It is the overall ability of the host to fight the disease causing organism.
Immune System : Consist of lymphoid organ, tissues, cells and soluble molecules like antibodies.
Innate immunity-
- Non-specific
- Present from birth
- Memory absent
- Physical barrier
- Physiological barrier
- Cellular barrier
- Cytokine barrier
Acquired immunity
- Pathogen specific
- Developed after birth
- Memory present
Active and Passive Immunity
Vaccination and Immunization
- Preparation of antigenic proteins of pathogen or inactivated/weakened pathogen are introduced into the body.
- Antibodies are generated in the body against these antigens.
- Neutralization of pathogenic agent
- Generation of memory B & T cells
- On subsequent exposure massive production of antibodies occurs.
Allergies
- Exaggerated response of the immune system to certain antigens present in the environment.
- Producing substances → Allergens
- Antibody produced → IgE antibody
- Symptoms → Sneezing, watery eyes, running nose and difficulty in breathing.
AIDS (Acquired Immuno Deficiency Syndrome)
- Acquired during life time, not a congenital disease.
- Ist reported in 1981 and had killed more than 25 million people worldwide.
Symptoms
- Early symptoms like bouts of fever, diarrhoea and weight loss.
- Due to decrease in the number of helper T lymphocytes, the person starts suffering from infections that could have been otherwise overcome such as those due to bacteria especially Mycobacterium, viruses, fungi and even parasites like Toxoplasma.
Treatment
- Partially effective with anti-retroviral drugs.
Prevention
- Use of disposable needles and syringes in public and private hospitals.
- Making blood banks safe from HIV.
- Controlling drug abuse.
- Avoid sex with unknown partners/multiple partners.
Cancer
- Most dreaded disease and major cause of death all over the world.
Treatment of Cancer
- Surgery
- Radiation therapy – Tumor cells are irradiated lethally.
- Chemotherapy – Several chemotherapeutic drugs are used. [Side effect – Hair loss, Anemia]
- Immunotherapy – Biological response modifiers such as α- interferon are used. These substances activate the immune system and help in destroying tumors.
Drugs And Alcohol Abuse
Tobacco
- Used by human beings for more than 400 years.
- Smoked, chewed or snuffed.
- Contains chemical substance – Nicotine (Alkaloid)
Smoking
- Increases carbon monoxide (CO) content in blood and reduces the concentration of haembound oxygen, causing oxygen deficiency in the body.
- Leads to incidence of cancers of lung, urinary bladder and throat, bronchitis, emphysema, coronary heart disease, gastric ulcer, etc.
2.0Microbes In Human Welfare
- Microbes are diverse – protozoa, bacteria, fungi and microscopic animal and plant viruses, viroids & also prions that are proteinaceous infectious agents.
- Microbes like bacteria and many fungi can be grown on nutritive media to form colonies that can be seen with the naked eye.
Microbes In Household Products
Lactic acid bacteria (LAB) eg. Lactobacillus - Curd
- Produce acids that coagulate and partially digest the milk proteins
- Improves nutritional quality (increases vit-B12)
- Checks disease causing microbes in stomach
Cheese - one of the oldest food items in which microbes were used.
- Different varieties of cheese are known by their characteristic texture, flavour and taste imparted by specific bacteria and fungi.
- Swiss cheese - large holes due to production of large amounts of CO2 by Propionibacterium sharmanii.
- Roquefort cheese – ripened by a specific fungi, which gives them a particular flavour.
Saccharomyces cerevisiae (baker’s yeast)
- Dough for dosa and idli and bread
- The puffed-up appearance of dough is due to the production of CO2 gas during fermentation.
Microbes In Industrial Products
Fermented Beverages
- Saccharomyces cerevisiae (brewer’s yeast) is used for fermenting malted cereals and fruit juices, to produce ethanol.
- Depending on the type of the raw material used for fermentation and the type of processing {with distillation (e.g. whisky, brandy and rum) or without distillation (e.g. wine and beer)} different types of alcoholic drinks are obtained.
Antibiotics Anti = against and bio = life (disease causing organisms)
- For human beings they are ‘pro life’ and not against.
- Produced by some microbes and can kill or retard the growth of other (disease-causing) microbes.
Microbes In Production Of Biogas
- Biogas is a mixture of gases (containing predominantly methane).
- Type of the gas produced depends upon the microbes and the organic substrates they utilise
- Methanogens: Eg. Methanobacterium
- Grow anaerobically on cellulosic material
- Produce large amount of methane along with CO2 & H2
- Commonly found in the anaerobic sludge during sewage treatment
- Also present in the rumen (a part of the stomach) of cattle.
- Play an important role in the nutrition of cattle.
Microbes As Biocontrol Agents
- Biocontrol refers to the use of biological methods for controlling plant diseases and pests.
- This reduces our dependence on toxic chemicals and pesticides.
- A key belief of the organic farmer is that biodiversity furthers health.
- Therefore, works to create a system where the insects that are sometimes called pests are not eradicated, but instead are kept at manageable levels by a complex system of checks and balances.
Microbes As Biofertilisers
- Biofertilisers are organisms that enrich the nutrient quality of the soil.
- The main sources of biofertilisers are bacteria, fungi and cyanobacteria.