Chapter B5- Communicable Diseases Flashcards
What is your health?
A state of physical and mental well-being, not just an absence of disease
What is a communicable disease?
A disease that can be passed from one organism to another
What is a pathogen?
Microorganisms that cause disease
What is a non communicable disease?
A disease that can not be transmitted from one organism to another
Give an example of a communicable disease
Tuberculosis
Flu
Give an example of a non communicable disease
Heart disease
Arthritis
What factors can affect your health?
Diet
Stress
Life situations (gender, class, ethnicity, level of healthcare provided, local sewage/rubbish disposal)
What are communicable diseases known as?
Infectious diseases
Give examples of pathogens?
Bacteria
Viruses
Protists
Fungi
What does harmful bacteria in your body do?
Bacteria divides rapidly by splitting in two. They may produce toxins that affect your body, and can damage your cells
What do viruses do?
Take control of the cell, live and reproduce inside of the cell, killing them
How do pathogens spread?
By air- coughing, sneezing, talking
Other people will breath in these droplets and pick up the infection
Direct contact- contact of healthy organism and infected one
By water- pathogen enters body through your digestive system
What do toxins do?
Damage tissues and make us feel ill
How can you reduce the spread of pathogens?
Basic hygiene- washing hands
Clean drinking water
Stopping from direct contact- using condoms curing sex and not sharing needles
Quarantine- cases such as Ebola, keeping the infected person away
Destroying or controlling vectors- killing mosquitos
Vaccinations- introduce a small part of a harmless form of a disease so that a persons immune system can learn to fight it off
How do you grow microorganisms?
Give them a culture medium- a liquid or gel containing nutrients
Warmth and oxygen are also needed.
Ensure you are avoiding unnecessary contamination
Be safe, in case of mutations that may be caused
What is the maximum temperature one schools that you can culture microorganisms?
25 degrees
What effect does temperature have when growing pathogens?
Too low a temperature- the likelihood of growing pathogens that might be harmful to people is less
Higher temperature- high risk of growing dangerous pathogens
How can you prevent bacterial growth?
Raise or lower temperature
Chemicals can be used to stop or kill them
What is a disinfectant?
Chemicals used to kill bacteria in the environment around us
What is an antiseptic?
A disinfectant that is safe to use on human skin
What is an antibiotic?
An antibiotic is a chemical that can be used inside our body, which kills bacteria or prevents them from growing
What did Ignaz Semmelweis notice?
That many women were dying in childbirth due to an unknown reason. He realised that his medical students would go from dissecting a dead body to birthing children. He also noticed that a doctor died from similar symptoms as the women birthing children, when he got a cut on his hand whilst aiding a childbirth. He concluded that there was an infectious agent, and demanded his students washed their hands before delivering babies. Immediately there were fewer deaths.
What other discoveries were there in the mid-late 19th century?
Louis Pasteur showed that microorganisms caused disease. He developed vaccine against diseases such an anthrax
Joseph Lister started to use antiseptics on pathogens in operating theatres to destroy harmful pathogens
Microscopes improves so that pathogens could be seen more clearly- helped convince people they existed
Give examples of a viral disease
Measles- spread by inhalation of droplets from coughs and sneezes
HIV/AIDS- spread through sexual contact or exchange of bodily fluids
Tobacco mosaic virus- spread by direct contact, or by vectors
What are symptoms of measles?
Fever and a red skin rash
What can prevent the development of aids?
Antiretroviral drugs
Why is measles now rare in the uk?
Due to vaccinations and infected people being isolated
Why is untreated HIV usually fatal?
It develops into AIDS, and attacks your immune system, so even a common cold can kill you
Can viruses be killed by antibiotics?
No
What damage does measles cause?
Problems with the breathing system and the brain
What is the first symptom of HIV?
A flu like illness
Where can salmonella be found?
Raw eggs
Raw meat
Raw poultry
What happens if salmonella gets into our bodies?
Disrupt the balance of natural bacteria and cause salmonella food poisoning
What the symptoms of salmonella?
Fever
Abdominal cramps
Vomiting
Diarrhoea
Who is salmonella most dangerous to?
Young children or the elderly
How can you prevent salmonella?
In the uk, poultry is vaccinated against salmonella
Keep raw chicken away from food that is eaten uncooked
Avoid washing raw chicken
Wash hands and surfaces after handling raw chicken
Cook chicken thoroughly
How is gonorrhoea spread?
Unprotected sexual contact with an infected person
What are the early symptoms of gonorrhoea?
Thick yellow or green discharge from the vagina or penis, and pain on urination
Can gonorrhoea be treated with antibiotics?
Yes
How can you reduce the spread of gonorrhoea?
Sex using a barrier such as a condom
Reducing the number of sexual partners
Can bacteria be killed using antibiotics?
Yes
Give an example of a fungal disease that can affect humans
Athletes foot
What can humans use against fungi infections?
Anti fungal drugs
What is rose black spot?
A fungal disease on rose leaves
What does rose black spot do?
Causes purple or black spots to develop on leaves- this is bad for commercial flower growers.
Eventually the leaves turn yellow and drop early. This reduces the area of leaves available for photosynthesis- as a result the plant does not flower well.
How is rose black spot spread?
Spread in the environment, as the fungus is carried by the wind. Then spread as drips of water splash from one leaf to another
How can gardeners treat/ prevent rose black spot?
Chemical fungicides help to treat the disease and stop it from spreading
Burning or removing infected areas
Horticulturalists have bred roses that are relatively resistant
Is rose black spot curable?
No
Give an example of a protist disease
Malaria
What is malaria?
A disease caused by protist pathogens that are parasites- they live and feed on other organisms
How is malaria spread? You
The protists sexually reproduce in the mosquito, and when the mosquito bites humans to such their blood, the protists spread to the humans, where they can then asexually reproduce by travelling around the circulatory system
What are the symptoms of malaria?
Fever and shaking
Potential death
Weakens the person over time
Can malaria be treated?
If recognised quickly, a variety of drugs can treat it
How can we stop the spread of malaria?
Using insecticides to kill mosquitos in homes and offices
Preventing the vectors from breeding by spraying water with insecticides to kill the larvae
Travellers can take antimalarial drugs that kill the parasites in the blood of they are bitten
Using mosquito nets to prevent being bitten
What are adaptations of your skin to defend the body from disease?
The skin covers your body and acts as a barrier. It’s prevents the bacteria and viruses from reaching the tissues beneath.
Your skin is covered in dead skin cells which are hard to penetrate
Your skin produces anti microbial secretions called sebum that destroy pathogenic bacteria
Healthy skin is covered by microorganisms that help keep you healthy and act as an extra barrier to the energy of pathogens
How does your nose defend against disease?
Your nose is full of hairs and mucus, which trap particles in the air that may contain pathogens or that may irritate your lungs.
How do your trachea and bronchi defend against disease?
Secrete mucus that traps pathogens in the air
Covered in cilia- wafts the mucus up to the back of the throat where it is swallowed
How does the stomach defend against disease?
Produces acid that destroys the microorganisms in the mucus you swallow and the majority of pathogens you take in through your mouth via food and drink
How does he immune system protect you from pathogens?
White blood cells- will ingest pathogens, destroying them so they cannot make you ill
Release antibodies- target particular bacteria or viruses and destroy them. Once your body has created antibodies once, it can make them again very quickly if you come back in contact with the disease- stopping you from getting the disease twice
Producing antitoxins- counteract the toxins released by the pathogens
Why is your mucus green when your ill?
As some white blood cells contain a green coloured enzyme. These destroy cold viruses and any bacteria trapped in the mucus of your nose.
Then the dead white blood cells, along with the harmful pathogens, are removed in the mucus, making it look green
What is the non specific defence system?
First line of defence against pathogens- includes the skin, the nose, the trachea, the broncos and the stomach
What is phagocytosis?
The process where white blood cells ingest pathogens, and kill them using enzymes
What are antibodies made up of?
Protein molecules
How can we kill aphids?
Chemical pesticides
Growing in enclosed spaces
Releasing aphid eating insects such as ladybirds
Give examples of non communicable plant diseases
Mineral deficiencies in yeh soil can result in plants not growing
Magnesium deficiency
Nitrate deficiency
What happens if a plant doesn’t have enough nitrate?
Protein growth is limited as nitrate is needed to turn the sugars made in photosynthesis into proteins. This can result in the growth of plants being stunted, and they will not produce a crop properly
What happens if a plant doesn’t have enough magnesium ions?
Magnesium is required to make the chlorophyll needed for photosynthesis. If yeh magnesium level is low, the leaves will become yellow and growth slows down due to the plant being unable to photosynthesise properly. This is known as chlorosis
What are plant defence responses?
Physical barriers- the cell walls, the waxy cuticles, the bark on trees, the leaf fall
Chemical barriers- produce antibacterial chemicals that kill pathogens
Defence against herbivores- poisons, thorns, hairy stems, dropping/curling, mimicry
How do cells walls protect the plant?
Strengthen the plant to help resist invasion by microorganisms
How does yeh waxy cuticle protect the plant?
Acts as a barrier to the entry of pathogens
How does bark on trees protect the plant?
A protective layer that is hard to breach
When the dead cells fall off, so does yeh pathogens on them
How does leaf fall protect the plant?
Some trees love their leaves in autumn- this causes pathogens that have infected the leaves to fall off the tree when the leaves are lost
Can plant chemical barriers aid humans?
Mint and hazel are often used as mild antiseptics in cosmetics and over the counter medicines. Doctors are also looking into plants having potentially antibiotic properties, with example being pines, cypress and euphorbias
How do poisons protect a plant?
Prevent the animal from eating the plant as it makes them feel unwell
How do thorns protect the plant?
Thorns make it unpleasant or painful for large herbivores to eat them
How do hairy stems protect the plant?
Deter insects and large animals from laying eggs on them or eating them
How does dropping or curling protect the plant?
The leaves will collapse suddenly, dislodging insects and frightening larger animals
How does mimicry protect the plant?
Some plants droops to mimic unhealthy plants, which tricks animals into not eating them. Some also mimic butterfly eggs, so real butterflies do not lay eggs on them in order to avoid competition.
What is smaller- viruses or bacteria?
Viruses
What is a genetic disease?
A disease caused by abnormality in the genes
What is a pandemic?
A disease that is prevalent over one country or area
What is an epidemic?
A wide spread occurrence of an infectious disease in a community at a particular time that
What is crown hall disease?
Causes a mass of unspecialised cells to grow at the joint between the stem and the shoot. This is a pathogenic disease
What is tobacco mosaic virus?
Causes a distinctive mosaic pattern of discolouration on the leaves- affects the growth of the plant as the lament cannot photosynthesise as well. This is a pathogenic disease
Are aphids pathogenic?
Yes
How does iron deficiency affect a plant?
Iron is needed to produce chlorophyll, so deficiency causes yellowing leaves, which limit the plants ability to photosynthesise.
