Biology HT2
What are the 4 pathogens?
protist
bacteria
virus
fungi
The three ways that diseases are transmitted:
direct contact
water
air
How is athlete's foot spread?
direct contact
What are ways of preventing infection?
hygiene
vaccination
decreased vectors
isolation
What are viruses?
Viruses are tiny non-living (acellular) particles that can reproduce rapidly within the body.
What are some examples of viruses?
measles
HIV
TMV
What are some ideal conditions for bacteria to reproduce?
warm
moist
good supply of oxygen
What is bacteria?
Bacteria are tiny, single-celled living organisms.
What is fungi?
Fungi are unicellular or multicellular organisms that have bodies made up of hyphae (thread-like structures).
What do fungi produce to spread to other plants and animals?
spores
Protists are often transferred to the host organism by a?
vector e.g mosquitos
What is a protist?
Protists are simple eukaryotic organisms that are neither plants nor animals or fungi.
What kind of acid does the stomach produce?
Hydrochloric acid
What are the main functions of the white blood cells in our immune system?
produce antitoxins
produce antibodies
phagocytosis
What are antigens?
Antigens are proteins found on the surface of some cells.
What is the name given to the cells produced during vaccination that remain in the body?
Memory cells
Describe the process of phagocytosis:
A white blood cell finds the pathogen and engulfs it by changing shape.
The white blood cell ingests and digests the pathogen, destroying it.
In what form are the pathogens found in vaccinations?
Dead or Inactive
What is a non-communicable disease?
A disease that cannot spread
Are viruses living organisms?
no
What does health mean?
It is a state of physical/mental well-being
What does bacteria do?
They reproduce by splitting into 2 (binary fission)
They make us ill by producing toxins
Diseases include salmonella, food poisoning, gonorrhoea
What do viruses do?
They are smaller than bacteria
The host cell bursts spreading the virus to surrounding cells
Diseases include measles, HIV, TMV
What do protists do?
They are single-celled eukaryotes e.g parasites
They are trasferred by a vector
Diseases include malaria
What does fungi do?
They are the largest of the pathogens
They spread by producing spores to other organisms
Diseases include athletes foot, RBS (Rose Black Spot)
How to calculate bacteria growth?
Calculate how many times the bacteria divide
Calculate the number of bacteria in the population
e.g Bacteria at the begining x 2 squared by the num of divisions
What is the CID SAM of preventing bacteria growth?
dependent = the chemicals that kill the bacteria
independent = how much bacteria died in one area
control = the temp
What is in the nose to stop pathogens from entering
mucus, nose hairs and cilia
What is phagocytosis?
The process by which a phagocyte (a type of white blood cell) surrounds and destroys foreign substances (such as bacteria) and removes dead cells.
What are lymphocytes?
Lymphocytes are the white blood cells involved in the specific immune response. They produce antibodies that respond to specific antigens on the surface of pathogens.
What are common signs of plant disease?
Stunted growth from mealybugs.
Spots on leaves caused by the rose black spot fungus.
Decay caused by the rice blast fungus.
Malformed stems or leaves caused by the ash dieback fungus.
Discoloration caused by the tobacco mosaic virus.
The presence of pests (aphids)
What are some properties of antibiotics?
To kill bacteria
Examples are penicillin
What are some properties of painkillers?
To treat symptoms/relieve pain
Examples are paracetamol, aspirin, ibupurofen and morphine
How can measles be spread between people?
Via droplets in air when an infected person coughs or sneezes.
What does the MMR vaccine protect you against?
measles, mumps and rubella
What were traditional drugs extracted from?
Plants and microorganisms
What did the heart drug digitalis originate from?
foxgloves
What does efficacy mean?
The ability to produce a desired or intended result.
What does toxicity mean?
The quality of being toxic or poisonous.
What does dosage mean?
The size or frequency of a dose of a medicine or drug.
What are some features of clinical trials?
Very low doses of the drug are given at the start
If the drug is safe, further tests will be taken to find out the optimal dose for the drug
In double blind trials, some patients are given a placebo
What is a monoclonal antibody?
Monoclonal antibodies. are identical copies of one type of antibody.
When are monoclonal antibodies used?
For pregnancy tests
What is the main advantage for monoclonal antibodies?
Only cancer cells are killed not like standard chemo or radiotherapy which kill other cells.
What are some treatments for cancer?
Chemotherapy
Radiotherapy
Monoclonal antibodies
What are the two types of tumours?
Malignant - these tumours are cancerous and can break apart, move around the body and start new cancers
Benign - these tumours are less serious because they are not cancerous, and do not spread.
Why is HIV dangerous?
It can suppress the immune system and makes people more susceptible to catching other infectious diseases.
What do we call the proteins on cell surfaces that identify cells as 'self' or 'foreign'?
Antigens