Communicable Diseases and Plant Defenses

Communicable Diseases

• Communicable diseases are illnesses caused by infectious agents like bacteria, viruses, fungi, or parasites.
• Transmission routes can include direct contact, airborne droplets, contaminated food or water, or vectors.
• Examples include influenza, HIV/AIDS, tuberculosis, and malaria.
• Diagnostic methods range from observing symptoms to laboratory tests like blood tests and cultures.

Plant Defenses

• Plants, lacking a mobile immune system like animals, employ various defense mechanisms to protect against pathogens and herbivores.
• These defenses can be categorized as physical, chemical, and mechanical.
• Physical barriers include the plant's cuticle, cell walls, and bark.
• Chemical defenses encompass the production of toxins, antimicrobial compounds, and defensive proteins.
• Mechanical defenses involve thorns, spines, and trichomes.
• Some mechanisms are constitutive (always present), while others are induced in response to pathogen attack.

Non-Specific Defenses

• Non-specific defenses, also known as innate immunity, are the body's first line of defense against pathogens.
• These defenses provide a general response to a wide range of pathogens, not targeting a specific one.
• Examples include the skin, mucous membranes, inflammatory response, fever, and phagocytosis.
• Skin acts as a physical barrier, while mucous membranes trap pathogens.
• The inflammatory response isolates infected areas and promotes healing.
• Fever increases body temperature, slowing pathogen replication.
• Phagocytes, like macrophages and neutrophils, engulf and destroy pathogens.

Monoclonal Antibodies

• Monoclonal antibodies (mAbs) are identical antibodies produced in the laboratory from a single clone of B-cells.
• They have a single specificity, targeting a particular antigen.
• Compared to polyclonal antibodies, mAbs are more uniform and have higher specificity.
• Production involves fusing a B-cell producing the desired antibody to a myeloma (cancer) cell, creating a hybridoma.
• Hybridoma cells then produce large quantities of the specific antibody.
• Monoclonal antibodies find broad applications in diagnostics, research, and therapeutics—specifically treating cancer, autoimmune diseases, and infections.
• Examples include treatments for some types of cancer, autoimmune diseases like rheumatoid arthritis, and some viral infections.
• Important aspects include the method of production, high specificity, and diverse applications.