Biology Topic 3

A disease that can be passed from one organism to another.

Pathogens - Microorganisms that causes disease.

• Fungi - Spores, cause Rose Black Spot.
• Virus - Take over the cells cause Measles, HIV/ AIDs, Tobacco Mosaic Virus.
• Bacteria - Binary fission (DNA replicates), a toxin, causes Salmonella.
• Protists - Vector, Insecticide, For example, Mosquitoes carry Malaria.

Preventing infection

• Destroy or control vectors and Isolation or seperation for hosts.
• Hygene - Handwashing, disinfectant, tissues, clean equipment.

Vaccination - Dead or inactive patogens are injected. E.g. MMR - Measles, mumps and rubella.

• Future infections are beaten rapidly as the antigens stimulate the antibodies (faster response).
• Herd immunity.

A disease that can not be passed from one organism to another.

• Cancer - Melignant (spreads), Benign (stays 1 place), Tumours.
• Casual Mechanism - 1 factor influences another through a biological process.
• Smoking -  Narrows blood vessels, carcinogen (cancerous) cause heart attacks, strokes.
• Alcohol - Addictive, carcinogen, causes brain & liver damage.
• Diet & Exercise - Fatty build up, lack nutrients, cause obesity, Type 2 diabetes, anemia, rickets.
• Risk Factors - Life style & Environment.

Health - State of physical and mental wellbeing.

Immune system - The organs and processes of the body that provide resistance to infection and toxins.

• Respiratory & Digestive system - Stomach acid, nose hair and mucus, cilia, trachea & bronchi coated with mucus.

• Skin - Protective barrier, hairs on the skin.

• White Blood Cells - Ingest pathogens, produce antitoxins & antibodies.

Monoclonal Antibodies

• Produced from a single clone of a cell.
• Proteins target the cells & chemicals.
• Used in pregnancy tests
• Target & bind specific antigens.
• Form of cancer treatment.

Plant Disease

• Mineral Deficiency - Yellowing leaves, nitrates - stop growing.
• Vectors - Aphids, feed on the glucose and nutrients.
• Detecting - Growth, leaf spots, decay, pests, discolour.

Plant Defence Systems

• Physical Barriers - Cellulose cell wall to strengthen, bark, waxy cuticle.
• Chemical Barrier - Antibacterial, pesticides.
• Defence Against Herbivores - Poison,thorns, hairy stems & leaves.

Bacterial Growth

• PH and oxygen levels affect the rate.
• Nutrients are needed.

Development

• Good medicine - Safe, effective, stabel, taken and leaves body.
• Pre-clinical testing - Live animals, cell tissue, efficiancy.

Clinical trials 

• 1) Low dose, Side effects 
• 2) Small group of patients, Efficiency                         
• 3) Bigger group, Dosage 
• 4) Double blind, Effectivness.

Antibiotics

• Example: Penicilin - made from mold spores
• Cure bacterial diseases (from micro-organisms, not viral) builds resistant bacteria.

Painkillers

• DOES NOT cure,Relieves symptoms - for example: Asprin, Ibruprofen & Paracetamol.