B6.3 - Monitoring & Maintaining Health Flashcards
1
Q
Disease
A
= a condition caused by any part of the body not functioning properly
Affects physical & mental health
2
Q
Relationship between health and disease
A
Good health = no disease
3
Q
Communicable disease
A
- diseases spread between organisms
- caused by pathogens (microorganisms cause disease when they enter the organism, parasites: lives on/in host organism and gets its food from or at the expense of its host)
4
Q
Causes and examples of non-communicable diseases
A
- poor diet (vitamin/mineral deficiencies)
- obesity (arthritis, type 2 diabetes, heart disease, stroke)
- inheriting a genetic disease (cystic fibrosis)
- body processes not operating correctly (cells divide uncontrollably = cancer)
5
Q
Types of pathogens that causes diseases
A
- fungi
- bacteria
- viruses
- protists/protozoa
6
Q
How are HPV & cervical cancer linked
A
- HPV can cause cell chances that lead to cervical cancer
- therefore girls vaccinated against HPV, reduced cervical cancer
(HPV = communicable, Cervical cancer = non-communicable)
7
Q
How are HIV and AIDS linked
A
- HIV invades white blood cells & reproduces inside them
- weakens immune system (affected cells can’t produce antibiotics to defend against disease)
- without antibodies, body becomes target of everyday infections & cell changes cause cancers (AIDS)
- AIDS = final stage of HIV infection, body can’t fight life-threatening infections
8
Q
How are HIV & tuberculosis linked
A
- HIV causes AIDS, weakens persons immune system, easier for microorganisms (tuberculosis-causing bacteria) to cause disease
- many ppl with HIV die from tuberculosis
(HIV = communicable, tuberculosis = non-communicable)
9
Q
How can pathogens spread between animals
A
Through:
- cuts in skin (injury, insect/animal bites)
- digestive system (shared foods/drinks)
- respiratory system (inhaling)
- reproductive system (sexual intercourse)
10
Q
How can pathogens spread between plants
A
- through soil/water in which plants grow
- vectors (insects)
- direct contact of sap from infected plant with healthy plant (sap released by agricultural damage / animals feeding on plants)
- wind (fungal spores / infected seeds blown between plants)
11
Q
Incubation period
A
Time delay between harmful microorganisms entering body & feeling unwell
- pathogens grow & reproduce rapidly, cause cell damage
- some pathogens produce toxic waste products, cause range of symptoms (fever, rashes, sores)
12
Q
Viral replication (how viruses replicate)
A
Can’t replicate themselves, take over & use host organisms cells to make more viruses
- virus attacks cell
- inserts its genes
- tells nucleus to copy its genes
- new viruses made
- cell bursts, releasing new viruses & destroying cell
13
Q
Incidence of a disease
A
Rate at which new cases occur in a population over a period of time
(used by scientists to monitor a disease outbreak)
14
Q
How can you prevent the spread of a communicable disease
A
- cover mouth/nose when you cough/sneeze
- don’t touch infected people/objects
- use protection during sexual intercourse
- don’t share needles (used to inject drugs)
- wash hands before eating
- cook food properly (kills bacteria)
- drink clean water (boil/sterilisation tablets)
- protect from animal bites (insect-repellant spray)
15
Q
Antigens
A
= proteins on the surface of a microorganism
16
Q
How are diseases identified by farmers
A
- changes to organisms appearance
- identifying pathogen by its DNA / antigens
17
Q
How do farmers prevent the spread of communicable disease in plants/animals
A
- diseases plant material burnt
- animals treated using drugs, but some require whole herds to be slaughtered
- livestock can’t be moved
- chemical dips installed on forms to kill pathogens on footwear
- spray plants with fungicides, prevent fungal disease
- animals vaccinated against some pathogens
18
Q
Athletes foot
A
- caused by group of parasitic fungi (dermatophytes)
- feet have warm, humid environment = dermatophytes live & multiply
- symptoms = cracked, flaking, itchy skin
- treating with anti-fungal cream
- highly contagious (easily transmitted)
19
Q
Food poisoning
A
- caused by growth of microorganisms in food
- most serious caused by bacteria & toxins produced
- these bacteria survive refrigeration & freezer storage, thorough cooking kills them
- symptoms = stomach pains, diarrhoea, vomiting, fever
- some recover, some use a drip to replace fluids, some die
20
Q
3 main groups of bacteria causing food poisoning:
A
- salmonella : found in raw meat, eggs, raw unwashed vegetables, unpasteurised milk
- campylobacter: found in raw meat, unpasteurised milk, untreated water
- E.coli: found in raw & undercooked meats, unpasteurised milk & dairy
21
Q
Types of Sexually Transmitted Infections (STI)
A
- chlamydia
- gonorrhoea
- genital heroes
- HIV
22
Q
Chlamydia
A
- cause: bacteria
- symptoms: pain when urinating, discharge from penis/vagina
- treatment: antibiotics
23
Q
Gonorrhoea
A
- cause: bacteria
- symptoms: burning pain when urinating, vaginal discharge
- treatment: antibiotics
24
Q
Genial herpes
A
- cause: virus
- symptoms: painful blisters/sores
- treatment: no cure
25
HIV
- cause: virus
- symptoms: weakened immune system, often results in AIDS
- treatment: no cure, symptoms controlled with antiretroviral drugs
26
Types of plant diseases
- virus plant disease: tobacco mosaic virus
- bacterial plant disease: crown gall disease
- fungal plant disease: powdery mildew
27
Tobacco mosaic virus
- prevents chloroplast from forming = stunts growth of plant, attacks & makes leaves discoloured & mottled
- lowers quantity & quality of crop produced, doesn’t kill plant
- to prevent: remove infected plants, wash hands & equipment between planting, plant plants resistant to virus in previously infected soil to stop re-infection
28
Crown gall disease
- caused by genes in tumour-inducing plasmid in bacterium
- bacteria enters plant through wound, plasmid integrates into host genome, causes production of greater amounts of growth chemicals than normal
- leads to production of large tumour-like growth = galls
- galls can encircle plant stem/trunk, cutting off flow of sap = stunt growth, death
- to prevent spread: destroy & remove infected plants, don’t plant in same area for 2 years (till bacteria die out)
29
Powdery mildew (fungal disease)
- caused by different species of fungi
- symptoms: white powdery spots (fungal growth) on leaves & stems, fungus reduces growth, makes leaves drop off early = reduces crop yield
- viruses grows well in areas of high humidity & moderate temperature
- releases spores, spread by wind to to infect new crop
- controlled by spraying crop with fungicide
30
Types of plant defences
- physical defences: physical barriers, prevent microorganisms entering
- chemical defences: substances secreted by plant, kill microorganisms
31
Examples of chemical plant defences:
- insect repellents: repel insect vectors that carry disease (pine resin, citronella)
- insecticides: kill insects (pyrethrins)
- antibacterial compounds: kill bacteria (phenols)
- antifungal compounds: kill fungi (chitinases)
- cyanide: plant chemicals break down to form cyanide compounds when plant cell attacked, toxic to most living things
32
Why is a cuticle a physical plant defences
- epidermal cells covered in waxy cuticle
- prevents water loss from plant & direct contact between pathogens & epidermal cells (limits chance of infection)
- relatively thin (on aquatic plants) or extremely thick (cactus)
- hydrophobic (water repelling) nature prevents water from collecting on leaf surface = defence against fungal pathogens (require water on lead surface for spore germination)
33
Why is a cell wall a physical plant defence?
- defence against fungal & bacterial pathogens
- primary cell wall = provides structural support, made of cellulose (gives strength & flexibility) fibres cross linked with other substances (pectin), forms gel (helps cement neighbouring cells together)
- secondary cell wall = provides further structural barrier
- also contains variety of chemical defences, activated rapidly when cells detect pathogens
34
Diagnosis
Identifying a disease in a plant/animal
35
2 key techniques to identify plant diseases in the field
- observation
| - microscopy
36
2 key techniques to identify plant diseases in the laboratory
- DNA analysis
| - identification of antigens
39
DNA analysis for plant diseases in the laboratory
- every plant pathogen has unique genome, identified using DNA fingerprinting
- profile = map of genome produced,
- scientists compare unknown plant pathogens genome to known DNA profile
- if match found, accurate diagnosis made
- DNA profiles used to identify individual strains of microorganisms
40
Identification of antigens (plant diseases in the laboratory)
- plant pathogens carry specific antigens (proteins) on surface
- pathogen identified through chemical analysis
- scientists developed diagnostic kits, enable farmers to identify common crop pathogens
41
Advantage of identifying plant diseases in the laboratory over the field
- can identify plant pathogens before it causes significant damage to crop
- in field, only identified once infection taken hold & symptoms apparent
42
Visual symptoms (observation) of plant diseases
- strawberry mottle disease: discolours leaves of strawberry plant
- bacterial soft rot: rotting of plants leaves/fruit of cabbage
- powdery mildew: white, powdery deposit on plant
43
Microscopy to diagnose plant diseases
- plant pathologists(scientists who specialise in plant diseases) use microscopy to identify pathogens
- many plant pathogens identified using light microscopy
- some require electron microscopes to provide accurate diagnosis
