Studied by 27 peopleDescribe Aseptic technique.
Wash hands thoroughly and disinfect the work area
Flame the neck on the bottle before putting the lid on
Heat the inoculating loop for a few seconds
Lift the lid of the petri dish never fully removing it
What 3 factors do bacteria need to grow?
Nutrients (glucose)
Warmth
Oxygen
How do viruses cause disease?
Viruses live and reproduce rapidly inside an organisms cells. this can damage or destroy the cells.
Name 2 bacterial diseases.
Salmonella
Gonorrhoea
How does TMV affect the plant?
Reduces the plants ability to photosynthesise, affecting growth.
How does HIV affect the body?
The virus attacks the bodys immune cells,which can lead to AIDS where the immune system is so damaged that it cannot fight off infections or cancers.
What are the symptoms of TMV?
Mosaic patterns of discolouration on the leaves- where chlorophyll has been destroyed.
What are the symptoms of HIV?
Flu-like symptoms at first.
What are the symptoms of Measles?
Fever
Red-skin rash
Complications can be fatal
How is TMV spread?
Direct contact of plants with infected plant material
Animal and plant vectors
Soil: the pathogen can remain in soil for decades
How is HIV spread?
Sexual contact
exchange of bodily fluids (eg. blood)
How is Measles spread?
Inhalation of droplets produced by infected people when sneezing or coughing.
Name 3 viral diseases.
Measles
HIV
TMV (Tobacco mosaic virus)
How do antitoxins kill pathogens?
Bacteria can produce toxins that are harmful to the human body
White blood cells detect the toxins and produce antitoxins
the antitoxins neutralise the effects of toxins by counteracting the effect
Describe how a Lymphocyte (Antibodies) kills pathogens
Pathogens contain antigens on their surface
When white blood cells detect these antigens, they produce complementary antibodies in response
The antibodies lock onto the antigens rendering them useless, whilst other white blood cells can destroy them
Antibodies are specific to the pathogen and can be produced very quickly
What is an antigen?
A unique molecule that pathogens contain on their surface.
Describe how a phagocyte kills pathogens.
Identifies the pathogen and attaches itself to it
Cytoplasm surrounds and engulfs the pathogen
The pathogen is killed and digested
Indigestible residue is removed
Name the three types of white blood cell.
Phagocytes
Antibodies/ Lymphocytes
Antitoxin
What is a communicable disease?
Diseases that can be passed from one organism to another.
What is a non-communicable disease?
Disease that cannot be passed from one organism to another.
What is a vaccine?
Dead or inactive pathogenic material used in a vaccination to develop immunity to a disease in a healthy person.
What is a protist?
Single celled organisms. Can be pathogenic.
What is fungus?
Resemble plant cells but without chloroplasts. can be pathogenic.
What is bacteria?
Single celled prokaryotic organisms. Live outside the cell. Produce toxins that damage tissues and make us feel ill.
What is a virus?
Pathogens that reproduce inside living cells of other organisms, causing cell damage.
What are pathogens?
Micro-organisms that cause disease.
How does the immune system defend against pathogens?
Destroys pathogens using white blood cells.
How does the stomach defend against pathogens?
Produces hydrochloric acid which kills pathogens.
How does the trachea and bronchi defend against pathogens?
Secretes mucus
Covered in cilia
How does the nose defend against pathogens?
Full of hairs and produces mucus which traps pathogens.
How does the skin defend against pathogens?
Creates a barrier and produces antimicrobials in the oil it secretes.
Name 4 types of pathogens.
Bacteria
Fungus
Virus
Protists
How do health problems interact
Viruses can trigger changes in cells that lead to cancer
Immune reactions caused by pathogens can trigger allergies such as asthma
Severe physical ill health can lead to depression and other mental health problems
Malnutrition can be linked to obesity, weakened immune system, type 2 diabetes and cancer
How can life situations affect health?
Gender
Financial situation
Where you live
Health care provided
Children
Air pollution
How can stress affect health?
Heart disease → Heart attack
Certain cancers
Mental health problems → Insomnia
→ Anxiety
How can diet affect health?
Not eating enough →Starvation
→Defiency diseases
Eating too much → Obesity
→ Some cancers
→ Diabetes (type 2)
What 3 factors have an effect on health?
Diet
Stress
Life Situations
What is health?
A state of physical and mental wellbeing.
Name 4 ways we can control the spread of disease and give an example for each.
Hygiene- cleans away/kills pathogens
Isolating infected individuals- reduces the spread by limiting contact
Destroying/controlling vectors- reduces the spread of pathogens
Vaccination- Strengthens immune system defences against the disease
What mechanical adaptations help plants defend against disease?
Thorns and hairs stop animals eating plants
Leaves that droop or curl when touched to scare herbivores or dislodge insects
Some plants mimic the apperance of unhealthy or poisonous plants to deter insects or herbivores
What chemical barriers do plants use to prevent disease?
Many plants produce antibacterial chemicals
Poison production stops animals eating plants
What physical barriers do plants use to prevent disease?
Cellulose walls
Tough waxy cuticle
Bark on trees
How is malaria prevented?
Prevent mosquito vectors from breeding
Mosquito nets to prevent bites
Vaccinations
What is the treatment for malaria?
Anti-malarial medicine
What are the symptoms of malaria?
Recurrent episodes of fever
Can be fatal
How is malaria spread?
Mosquitos feed on the blood of infected people and spread the protist pathogen when they feed on another person.
What is the treatment for rose black spot?
Fungicides
Affected leaves removed and destroyed
How does rose black spot affect the plant?
Reduces the plant's ability to photosynthesise affecting growth.
What are the symptoms of rose black spot?
Purple or black spots on leaves, which turns yellow and drops early.
How does rose black spot spread?
Water and wind.
How is gonorrhoea treated?
Antibiotics (many antibiotic-resistant strains have appeared)
How is gonorrhoea prevented?
Barrier methods such as condoms
Monogamous partner
What are the symptoms of gonorrhoea?
Thick yellow or green discharge from the vagina or penis
Pain when urinating
How is gonorrhoea spread?
Direct sexual contact.
How is salmonella prevented?
Poultry are vaccinated against salmonella bacteria.
What are the symptoms of salmonella?
Diarrhoea
Fever
Abdominal cramps
Vomiting
How is salmonella spread?
Bacteria in or on food that is being ingested.
What is a toxin?
A harmful chemical produced by microorganisms
Name 3 positive effects of bacteria.
Assist in digesting food
Some bacteria produce vaccines, antibiotics and/or drugs
Act as decomposers
How can pathogens enter the body?
Water (eg drinking contaminated water)
Air (eg breathing in droplets)
Direct contact (eg touching an infected person)
What is a droplet infection?
An infection spread from one person to another by droplets of water released from the upper respiratory tract by sneezing/coughing. Can be prevented by wearing masks.
What are the features of a bacteria cell?
Single celled organisms
Have a circular strand of DNA rather than a nucleus
Do not contain mitochondria
May have a flagellum
Living cells
What are the physical features of a virus?
NOT cells
Smaller than bacteria
Consist of genetic material and a protein coat
How do bacteria cause disease?
Reproduce rapidly by splitting in 2 (binary fission) and produce toxins which can damage cells and tissues.
How do viruses cause disease?
Live and reproduce rapidly inside host cells, continuing until the cell bursts. Cell damage is what causes people to feel unwell.
What did Louis Pastuer develop?
Developed the germ theory of disease, showing that it was caused by living microorganisms.
What did Joseph Lister develop?
Introduced the use of carbolic acid to sterilise instruments and to clean wounds in surgeries.
What did Ignaz Semmelweis prove?
Proved that hand-washing could dramatically reduce the number of deaths during childbirth
What did Florence Nightingale introduce?
Introduced handwashing and other hygienic practices into hospitals.
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