B5 & B6 - Communicable diseases & Preventing and treating disease 1️⃣✅ Flashcards
What is a communicable disease?
A disease that can be transmitted from one organism to another.
What is a pathogen?
A microorganism that can cause disease
Name 4 types of pathogen.
Fungi, bacteria, virus & protists
How can pathogens spread?
Air, water & direct contact
How do bacteria make you feel ill?
By producing toxins that damage cells
How do viruses make you ill?
By reproducing rapidly inside cells & damaging or destroying them
Name 3 examples of a viral disease.
HIV, measles & tobacco mosaic virus
Name 2 examples of a bacterial disease.
Salmonella & gonorhoea
Name 4 methods of controlling the spread of communicable diseases.
Good hygiene, vaccination, isolating from infected individuals & controlling vectors
What is a vector?
A organism that transmits a pathogen e.g. aphids
What is an example of a fungal disease in plants?
Rose black spot - spread by water and wind, affects plant growth by reducing plants ability to photosynthesise.
What are 3 mechanical defences that protect plants?
Thorns/hairs, mimicry & droopy leaves
What are 3 physical defences that protect plants.?
Cellulose cell walls, tough waxy cuticles on leaves & bark on trees
What are 2 chemical defences that protect plants?
Poison & anti microbial chemicals
What are examples of the bodies first line of defence against pathogens?
Skin, nasal hairs, eyelashes & mucus in the nose
Give 3 jobs of white blood cells
phagocytosis, producing antibodies & producing antitoxins
What happens during phagocytosis?
A phagocyte is attracted to the area of infection, marked by an antibody. It then engulfs the pathogen, and releases enzymes to digest the pathogen
What are antigens?
Antigens are proteins on the surface of a pathogen.
Why are antibodies a specific defence?
Antibodies have to be the correct shape for a pathogen’s unique antigens, so they target a specific pathogen
What is the function of an antitoxin?
To neutralise toxins produced by pathogens by binding to them
What does a vaccine contain?
Small quantities of a dead or inactive form of a pathogen to stimulate white blood cells to produce antibodies
What is herd immunity?
When most of the population is vaccinated against disease, meaning its less likely to spread
What is an antibiotic?
Drugs that kill bacteria not viruses
What happens in the pre-clinical stage of a drug trail?
The drug is tested on cells, tissues and live animals
What is a placebo?
Medicine with no effect that is given to patients instead of the real drug in the trial
What is a double-blind trail?
A trial where neither patients nor doctors know who receives the real drug and who receives the placebo
What is a blind trail?
A trail where the doctor knows whether the patient has been given the real drug or the placebo
What are human trials?
The last stage of drug testing when drugs are tested on humans (healthy first then ill to see optimum dosage and side effects)
What is a open trial?
A trail where both the patient and doctor know if the patient has been given the real drug or placebo
What is the control group?
The group of people in a drug trail who are not given the new drug
What do painkillers do?
Painkillers only treat symptoms of disease & do not kill pathogens
What is an epidemic?
The widespread outbreak of a infectious disease within a country
What is a memory cell?
A white blood cell which remains in the blood after antibodies have been made.
What is a pandemic?
The widespread outbreak of a infectious disease that spreads rapidly across multiple countries
What is a symptom?
A sign of disease
What does it mean when something is antibiotic resistant?
When bacteria is not killed by an antibiotic medicine
What is immunity?
The quick production of antibodies by white blood cells in response to a pathogen that has previously entered the body to prevent a second infection from that same pathogen
What is a hybridoma?
A hybrid of a lymphocyte and tumour cell - can divide and grow endlessly, its purpose is to produce antibodies endlessly
How do pregnancy tests work?
1.Urine is applied to the end of the stick
2. The stick contains monoclonal antibodies that only bind HCG that are attached to dye
3. If HCG is present in the urine, the monoclonal antibodies cause a line of dye to appear. This means the test is positive
4. A second line appears on the test to show that the test is valid, even if the result is negative - control line
How are monoclonal antibodies used to treat cancer?
They are used for delivering toxic chemicals and drugs directly to cancer cells, limiting their harm to other cells in the body
What hormone do pregnant women produce and excrete in there urine?
HCG
Why do monoclonal antibodies need to be screened?
Because the fusion between tumour and lymphocytes only occurs on rare occasions
What is an example of a protist disease?
Malaria
Give 4 human defence systems
The nose
The skin
The stomach
The trachea & bronchi
Where does the heart drug digitalis originate from?
Foxgloves
Where does the painkiller aspirin originate from?
Willow
What was the first antibiotic discovered, how & who by?
Penicillin, from Penicillium mould by Alexander Fleming
What happens in clinical stages for the development of drugs?
Initially very low doses are given to healthy humans
If safe - further trails are carried out to discover the optimum dosage
How are monoclonal antibodies made?
- A mouse is injected with a particular antibody
- That mouse then produces lymphocytes for that specific antibody
- The lymphocytes are then combined with a rapidly dividing tumour cell
- The product of this combination is called a Hybridoma cell
- The hybridoma cell can produce the desired antibody and also divide rapidly
- The hybridoma is then cloned to make many identical cells that all produce the same antibody
- A large ammount of this antibody can be collected and screened for use on patients
Name 2 uses for monoclonal antibodies
- Pregnancy tests
- to treat disesases like cancer
Why are monoclonal antibodes not used as widley as intended when they were first produced?
Because they unfortunately create more side affects than expected.
What are some things plant diseases can be detected by?
- Stunted growth
- Spots on leaves
- Discolouration
- Areas of decay
- Malformed stems/ leaves
What is stunted growth caused by?
(In plants)
Nitrate deficiency
What is chlorosis caused by?
(In plants) (Chlorosis is another word for yellowing of leaves)
Magnesium deficiency
Why is stunted growth caused?
(explain why its cause is linked to stunted growth)
Stunted growth is caused by a nitrate deficiency
Nitrate ions are required for protein synthesis and therefore the production of amino acids so overall, without nitrate ions, a plant cannot produce enzymes (protiens) which are required for growth - therfore stunting the plants growth
Why is chlorosis caused?
(explain why its cause is linked to chlorosis/ yellowing of leaves)
Chlorosis is caused by a magnezium deficiency
Magnezium ions are required for the production of chlorophyll - the subcellular structure that causes leaves to appear green - therefore without magnezium ions and subsequently without chlorophyll, the plant wont be green and therefore will appear yellow
Measles
Type of disease, Symptoms, How is it spread & How is it treated
- Viral disease
- Fever and red skin rash
- Spread by inhilation of droplets from sneezes & coughs
- Vaccination
HIV
Type of disease, Symptoms, How is it spread & How is it treated
- Viral (STD)
- Intially flu-like symptoms which can develop (AIDS) when the bodys immune system becomes so badly damaged by the virus it can no loger deal with other infecitons or cancers
- Sexual contact or exchange of boily fluids e.g. blood
- Initially can be treated with antiretrovital drugs but late stage (AIDS) cannot be treated
Tobacco Mosaic Virus
Type of disease, Symptoms, How is it spread
- Viral
- Distinctive mosaic pattern of discolouration on the leaves which affects the growth of plant due to photosynthesis
- Vectors
Salmonella
Type of disease, Symptoms, How is it spread & How is it treated
- Bacterial
- Food poisoning - bacteria and toxins secreted therefore lead it vomiting, diarrhoea, abdominal cramps & a fever
- Bacteria in ingested food/ food prepared in unhygenic conditions
- Vaccine
Gonorrhoea
Type of disease, Symptoms, How is it spread & How is it treated
- Bacterial (STD)
- Thick yellow or green discharge from the vagina or penis and pain on urinating
- Bacterium through sexual contact
- Treatment with antibiotics or use of barrier method of contraception
Rose Black Spot
Type of disease, Symptoms, How is it spread & How is it treated
- Fungal
- Purple/ Black spots appear on leaves which often turn yellow an cause leaves to drop early - affecting photosynthesis & therefore growth
- Environment/ water/ wind
- Fungicides and removing/ destroying affected leaves
Malaria
Type of disease, Symptoms, How is it spread & How is it treated
- Protist
- Recurrent episodes of a fever and can be fatal
- Mosquitoes/ vectors
- Controlling vectors/ using mosquito nets
