Integrated Notes on Genetics, Health, and Disease

Applications of Genetic Engineering in Agriculture

  • Improving Crop Yields

  • Enhances growth rates of plants.

  • Enables crops to thrive in diverse conditions (e.g., heat, drought).

  • Allows plants to produce their own pesticides/herbicides.

  • Addressing Nutritional Deficiencies

  • Development of vitamin-rich crops (e.g., Golden Rice enriched with beta-carotene).

  • Useful in regions where certain nutrients are scarce.

  • Genetic Engineering Concerns

  • Potential unknown health effects of GM crops on humans.

  • Ethical dilemmas about extending genetic engineering from crops to humans, e.g., designer babies.

  • Increased agricultural yields may assist in alleviating world hunger due to population growth.

  • Environmental Risks

  • GM crops pose selection pressure on ecosystems, potentially leading to super weeds and pests.

Health and Disease Overview

  • Definitions

  • Health: State of physical and mental well-being.

  • Disease: Disorder impairing the body's normal functioning.

  • Types of Diseases

  • Communicable: Infectious diseases transmissible between individuals (e.g., chickenpox, malaria, HIV).

  • Non-Communicable: Diseases not spread between people (e.g., diabetes, heart disease, cancers). Factors often include lifestyle choices (diet, stress, exercise, alcohol).

  • Disease Interactions

  • HIV and TB: HIV weakens the immune system, making individuals more susceptible to TB.

  • HPV and Cervical Cancer: HPV is linked to the majority of cervical cancer cases.

Communicable Diseases

Viral Infections

  • Human Immunodeficiency Virus (HIV)

  • Symptoms: Initial flu-like signs.

  • Transmission: Through bodily fluids (sexual activities, shared needles).

  • Complications: Can advance to AIDS.

  • Treatment: Antiviral drugs, no cure yet.

  • Tobacco Mosaic Virus (TMV) (in plants)

  • Causes chlorosis in leaves, inhibiting photosynthesis.

  • Control measures: Hygiene, pest control, resistant strains.

Bacterial Diseases

  • Salmonella

  • Origin: Lives in animal guts, transmitted through contaminated food.

  • Symptoms: Fever, cramps, vomiting.

  • Prevention: Hygiene practices and thorough cooking.

  • Crown Gall Disease (Plants)

  • Involves DNA transfer that results in tumor-like growths on plants.

Fungal Diseases

  • Athlete's Foot (Humans)

  • Symptoms: Rash between toes.

  • Spread: Contact with infected surfaces.

  • Barley Powdery Mildew (Plants)

  • Causes chlorophyll loss and affects photosynthesis.

  • Treatment: Fungicides and removing infected parts.

Protist Diseases

  • Malaria

  • Symptoms: Shivering, fever due to blood cell lysis.

  • Transmission: Through female Anopheles mosquito.

  • Prevention: Insecticide nets, removing standing water.

Plant Defense Responses

  • Physical Defenses

  • Bark, cell walls, waxy leaf cuticles act as barriers.

  • Chemical Defenses

  • Antimicrobial substances: Produced by mint and witch hazel.

  • Poisons in plants like stinging nettles deter herbivory.

Detection of Plant Diseases

  • ELISA (Enzyme-Linked Immunosorbent Assay)

  1. Liquidize plant sample.

  2. Bind proteins to plastic tube.

  3. Add specific antibodies; color change indicates pathogen presence.

  • Polymerase Chain Reaction (PCR)

  • Amplifies DNA sequences for detection of infections.

The Immune System Overview

Non-Specific Defenses

  • Skin: Physical barrier, produces antimicrobials.

  • Nose & Mucus: Traps pathogens.

  • Phagocytes: Engulf and destroy pathogens.

Specific Defenses

  • Lymphocytes: Produce antibodies targeting specific pathogens.

  • Antitoxins: Neutralize harmful toxins.

Monoclonal Antibodies

  • Production Process

  1. Antigen injected into mouse.

  2. B cell production stimulated; hybridoma created from B cells and myeloma cells.

  3. Cloned cells produce identical antibodies.

  • Uses

  • Pregnancy tests: Identifies hCG in urine.

  • Cancer diagnosis/treatment: Targeting cancer antigens for detection and therapy by directly delivering drugs to cancer cells.

Vaccination

  • Mechanism: Introduces a harmless form of a pathogen to stimulate antibody production, leading to immunity.

  • Advantages: Prevents epidemics and has eradicated diseases like smallpox.

  • Disadvantages: Not always effective, rare side effects.

Antibiotics and Antivirals

  • Antibiotics: Target bacterial infections, ineffective against viruses.

  • Antimicrobials: Kill pathogenic microorganisms, often used to sterilize wounds.

  • Antiviral Drugs: Inhibit viral replication without harming body cells.

Non-communicable Diseases (NCDs)

  • Common NCDs: Cardiovascular diseases, diabetes, and cancers, influenced by lifestyle factors (obesity, alcohol consumption, smoking).

  • Cardiovascular Disease (CVD)

  • Risk factors include high cholesterol, smoking, high blood pressure.

  • Treatments involve lifestyle changes, statins, and surgical interventions like bypass surgeries.

  • Cancer: Caused by genetic mutations and environmental factors (carcinogens). Types: benign and malignant; malignant tumors can metastasize.

Stem Cells & Gene Technology in Medicine

  • Stem Cells: Potential for treating conditions like diabetes and regenerating damaged tissues; ethical concerns exist.

  • Gene Technology: Create insulin via recombinant DNA technology. Genetic engineering offers treatment for inherited conditions.

Human Genome Project

  • Improved understanding of genetic diseases and potential future treatments targeting genetic profiles.