Back to AI Flashcard MakerBiology /OCR Biology A - 4.1.1 - Communicable Disease, Disease Prevention and the Immune System Part 2
OCR Biology A - 4.1.1 - Communicable Disease, Disease Prevention and the Immune System Part 2
This flashcard deck covers key concepts from OCR Biology A, focusing on communicable diseases, disease prevention, and the immune system. It includes definitions, processes, and examples of plant and human defenses against pathogens.
Cause of malaria
Plasmodium parasite | It enters the human host via a bite from a female Anopheles mosquito
Tap or swipe ↕ to flip
Swipe ←→Navigate
1/25
Key Terms
Term
Definition
Cause of malaria
Plasmodium parasite | It enters the human host via a bite from a female Anopheles mosquito
Social factors affect direct transmission
Overcrowding Poor ventilation Poor sanitation Poor health - likely to contract other diseases Poor diet (malnutrition) Lack of education
Why is there a greater variety of diseases to be found in warmer climates
Many protoctists, bacteria and fungi can grow and reproduce more rapidly in warm and moist conditions
Why are plants targets for microorganisms
Manufacture sugars in photosynthesis and convert this into wide variety of compounds such as proteins and oils - rich source of nutrients for microorg...
Passive defences
Prevent entry
Active defences
Induced when pathogen is detected
Related Flashcard Decks
Study Tips
- Press F to enter focus mode for distraction-free studying
- Review cards regularly to improve retention
- Try to recall the answer before flipping the card
- Share this deck with friends to study together
| Term | Definition |
|---|---|
Cause of malaria | Plasmodium parasite | It enters the human host via a bite from a female Anopheles mosquito |
Social factors affect direct transmission | Overcrowding Poor ventilation Poor sanitation Poor health - likely to contract other diseases Poor diet (malnutrition) Lack of education |
Why is there a greater variety of diseases to be found in warmer climates | Many protoctists, bacteria and fungi can grow and reproduce more rapidly in warm and moist conditions |
Why are plants targets for microorganisms | Manufacture sugars in photosynthesis and convert this into wide variety of compounds such as proteins and oils - rich source of nutrients for microorganisms |
Passive defences | Prevent entry |
Active defences | Induced when pathogen is detected |
Plant passive defences | Cell wall Waxy cuticle Bark Stomatal closure Chemicals with anti pathogenic properties |
Plant active defences | Production of callose Strengthen cell walls with additional cellulose and lignin Tylose formation Wide range of chemicals produced Necrosis |
Callose as an active defence | Blocks plasmodesmata and sieve plates in the phloem, sealing off the infected part |
Tylose | Ballon like swelling that fills the xylem vessel. When a tylose is fully formed it blocks the vessel |
Necrosis as an active defence | Deliberate cell suicide | By killing cells surrounding the infections, pathogens access to water and nutrients is limited |
Chemicals produced as a part of plants active defences | Terpenoids Phenols Alkaloids Defensins Hydrolysis enzymes |
Terpenoids | Essential oils with anti-fungal and antibacterial properties |
Phenols | Have antibiotic and anti-fungal properties | Tannins bind to salivary proteins and digestive enzymes, deactivating them |
Alkaloids | Nitrogen-containing compounds that have a bitter taste to inhibit herbivores feeding Inhibit protein synthesis Also inhibit or activate enzyme action |
Defensins | Small cysteine-rich proteins with anti-microbial properties Act upon molecules in plasma membrane of pathogens |
Hydrolytic enzymes | Found in spaces between cells | Include chitinases, glucanases and lysozymes |
Glucanases | Hydrolyse glycosidic bonds in glucans |
Primary Defences | Defences that prevent pathogens from entering the body |
Non-specific defences | Prevent the entry of all pathogens |
Primary non-specific responses | Blood clotting; vessels/skin receptor Expulsive reflexes Stomach acid Tears (enzymes break down e.g. bacterial cell wall) Wax in ears Mucous membranes Skin Inflammatory response |
Main primary response | Skin |
Cells in epidermis | Keratinocytes |
How are keratinocytes produced | Cells produced at base by mitosis | Cells migrate to the top and keratinisation takes place |
Keratinisation | Cytoplasm dries out and is replaced by keratin | Keratinised layer forms an effective barrier to pathogens |