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.
Internal bleeding, muscular pain, fever, anemia, blockage of the intestinal passage
Eggs of the parasite excreted along with the the faeces of infected person which contaminate soil, water, plants
2.
Elephantiasis (Filariasis)
Wuchereria (W. bancrofti and W. malayi) (Filarial worm)
Slowly developing chronic inflammation of the organs in which they live for many years (Usually the lymphatic vessels of the lower limbs)
Genital organs are also often affected, resulting in gross deformities
Transmitted to a healthy person through the bite by the female mosquito vectors
Fungal Disease
Fungal Diseases
Pathogen
Symptoms & Pathogenicity
Ringworms
Microsporum, Trichophyton & Epidermophyton
One of the most common infectious disease
Appearance of dry, scaly lesions on various parts of the body such as skin, nails and scalp.
These lesions are accompanied by intense itching
Heat and moisture help these fungi to grow, which makes them thrive in skin folds such as those in the groin or between the toes
Generally acquired from soil or by using towels, clothes or even the comb of infected individuals
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
Active Immunity
Passive immunity
Produced actively by the immune system of the host.
Received passively by the host and the host immune system does not participate.
Induced by infection or by contact with immunogen Ex. Vaccines.
Conferred by introduction of readymade antibodies. Ex. Colostrum (yellowish fluid) secreted by mother has abundant IgA antibodies.
Active immunity is slow and takes time to give its full effective response.
Antibodies given in case of snake bites against snake venom.
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.
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.
Biology and Human Welfare refers to the application of biological knowledge and techniques to improve human health, agriculture, environment, and quality of life.
Biology helps by providing knowledge about pathogens, developing vaccines, antibiotics, antivirals, and promoting hygiene and sanitation practices to prevent and treat diseases.
Vaccines are biological preparations that provide immunity against specific diseases by stimulating the body's immune system to recognize and fight pathogens.
Biotechnology improves human welfare by producing medicines (like insulin), developing genetically modified (GM) crops for better yield and nutrition, creating biofuels, and aiding in environmental conservation.
Agriculture benefits through the development of high-yield crops, pest-resistant varieties, better irrigation methods, organic farming practices, and biofertilizers to enhance productivity sustainably.
Organic farming is a method of farming that avoids synthetic chemicals and relies on natural processes, promoting ecological balance and biodiversity.
Biology contributes by helping in disease prevention, developing vaccines and medicines, improving nutrition, promoting hygiene, and providing strategies for controlling epidemics.
Antibiotics are substances that kill or inhibit the growth of bacteria, helping to cure bacterial infections by targeting specific structures or functions within bacterial cells.