Communicable Diseases Flashcards
Definition of communicable and non-communicable diseases
Communicable = caused by pathogens that can be passed from one person to another Non-communicable = cannot be transmitted from one person to another
Examples of factors that can make you ill:
Diet = do not get enough to eat/right nutrients → anaemia, too much food or wrong type → diabetes and cancer
Stress = cancer and mental health
Life situations = gender, ethnic group, financial status, sewage, how many children you have, healthcare
How health problems interact
Viruses living in cells = cancer
Immune system helps destroy pathogens = defects in your immune system. not work effectively
Immune reactions = common cold, allergies
Physical and mental health
Malnutrition = diabetes, cancer
Differences between bacteria and viruses
Bacteria:
Free-living cells
Live inside and outside the body
Divide and excrete toxins, damaging cells
Viruses:
Non-living
Need a host to live
Live inside cells, destroying them
How pathogens are spread
Air = expel droplets full of pathogens when you cough sneeze or talk, the other breathe in droplets
Direct contact = STD’s, plant diseases, cuts scratches and shared blood
Water = salmonella, drinking water containing sewage, fungal spores
Growing microorganisms practical
1) Sterilise agar gel and inoculating loop
2) Pour agar plates and allow to set fully
3) Sterilise loop in Bunsen burner
4) Dip inoculation loop into the microorganism solution and make streaks on agar
5) Quickly put lid on and secure with tape
6) Label plate and store it upside down
7) Incubate at maximum temperature of 25 degrees (room temperature in schools
Preventing pathogens from spreading
Hand washing (before cooking and after using toilet)
Using disinfectants (kitchen surfaces and toilets)
Keeping raw meat ad uncooked food away from each other
Coughing or sneezing into a handkerchief
Maintaining hygiene of people and agricultural machinery
Isolated infected individuals
Destroying or controlling vectors
Vaccines
Measles
Virus
Spread by water droplets in air and surfaces
Ill children
Cold, red eyes, high temperature, rash
HIV/AIDS
Virus
Attacks immune cells
Remains hidden inside immune system
Spread by sexual contact and exchange of bodily fluids (blood)
No cure
No vaccine
Prevented using condoms and not sharing needles, drugs help
Tobacco Mosaic Virus
Discolouration on leaves Virus destroys the cells Affects growth Affected areas of the leaf and do not photosynthesise Reduces yield of a crop Spread by contact Insects act as vectors Can remain infectious in soil for about 50 yrs No treatment Now grow TMV resistant strains
Salmonella
Bacteria Lives in the guts of animals Disrupts balance of natural gut bacteria Uncooked food Vomiting, diarrhoea = caused by bacteria and toxins they secrete No antibiotics given Poultry vaccinated against salmonella
Gonorrhoea
Bacteria
STD
Spread by unprotected sex with infected person
Thick yellow or green discharge, pain on urination, long term pelvic pain, infertility
Some get no symptoms
Difficult to treat
Prevent spread using barrier protection (condoms)
Bacterial disease in plants
Bacteria
Causes crown galls
Infects fruit trees, vegetables and garden flowering plants
Bacteria insert plasmids in to plant cells and cause mass undifferentiated genetically modified cells to grow
Scientists can manipulate bacteria so they carry desirable genes into cells they infect
Fungal Diseases
Athlete’s foot
Can be fatal if some fungal diseases attack lungs and brain
Antifungal drugs used
In plants fungal diseases are common
Rose Black Spot
Fungal disease
Purple or black spots develop on leaves
Weakening plant
Reduces area of leaves available for photosynthesis
Spreads by wind or water (rain)
Prevent spread by removing and burning affected leaves and stem
Cannot be prevented or cured
Malaria
Protist Pathogens
Life and feed on other organisms
Cycle of protists include time in human body and time in female mosquito
Reproduce sexually and asexually in human body
Mosquitos = vectors
Need 2 meals of human blood so female can lay eggs
Affect liver and damage red blood cells
Causes recurrent episodes of fever and shaking when protists burst out of blood cells, can be fatal
Spread can be controlled by:
- insect nets
- insecticides (kill mosquitos)
- preventing vectors for breeding
- can take antimalarial drugs
Similarities and Differences between rose black spot and tobacco mosaic virus
Similarities:
Both reduce rate of photosynthesis
Reduce growth of plant
Differences:
RBS is a fungal infection
RBS causes dark spots and leaves turn yellow and fall off
TMV causes mosaic discolouration on leaves
Skin Defences
Prevents bacteria and viruses reaching tissue
Get cut, body restores it and forms clot
Produces antimicrobial secretions destroys pathogenic bacteria
Covered in microorganisms, extra barrier prevents entry of pathogens
Defences of Respiratory and Digestive Systems
Nose hairs and mucus = trap particles and pathogens that can irritate lungs
Trachea and bronchi secretes mucus = traps pathogens, lining of tubes covered in cilia wafting mucus up to back of throat where it’s swallowed
Stomach acid = destroys microorganisms in mucus you swallow
How white blood cells protect you against disease?
Some white blood cells ingest pathogens destroying them
Some produce antibodies specific to each type of pathogen
Some produce antitoxins which counteract toxins released by pathogens
Detecting Diseases in plants
Stunted growth Spots on leaves Areas of decay or rotting Growths Malformed stems and leaves Discoloration Presence of visible pests
Aphids
Penetrate into phloem vessels
Act as vectors transferring viruses, bacteria and fungi from diseases plants into the tissues of healthy plants on their mouthparts
Destroyed using pesticides
Plants fail to grow
Non-Communicable Plant Diseases (how magnesium ions affect plants)
Plants take magnesium ions from soil to make chlorophyll
If level of magnesium ions in soil is low, leaves become yellow and growth slows because plants can’t photosynthesise
Known as chlorisis
Plant’s physical barriers
Cellulose cell walls = resist invasion by microorganisms
Waxy cuticle = surface of leaf, barrier
Bark = layer of dead cells, hard for pathogens to penetrate, dead cells are lost or shred, pathogens fall off with bark
Leaf fall = deciduous trees lose leaves in autumn
Thorns
Hairy stems/leaves
Drooping or curling when touches
Mimicry = plants droop
Chemical barriers in plants
Plants produce antibacterial chemicals, protect them against invasion of pathogens
Poisons
