B5- Health, Disease, and the Development of Medicines Flashcards
What are communicable diseases?
Diseases that can spread between people (e.g. coronavirus)
What are non-communicable diseases?
Diseases that can spread between people (e.g. cancer)
What are pathogens?
Organisms that cause communicable diseases
Examples of pathogens
- bacteria
- viruses
- fungi
- protists
Define ‘health’
A state of complete physical, mental, and social well-being
Explain how having one disease can affect the likelihood of a person getting another, different disease
As their body may have become weakened by the first disease, so its less able to fight off other diseases
Which type of pathogen causes Ebola?
A virus
Which type of pathogen causes malaria?
A protist
What would a tree infected with Chalara ash dieback look like?
- lost leaves
- have lesions on its bark
Cholera is spread by water, how could a person pick up the pathogen that causes cholera?
By drinking or bathing in contaminated water
How can disease be spread?
- through air
- contaminated food
- contaminated water
- exchanging bodily fluids
- carried by an animal vector
Why are people infected with tuberculosis advised not to go to school or work, even if they feel well enough to go?
- its spread by air so those infected with it should avoid crowded public spaces in case they spread the disease bu coughing near other people
Explain how you can reduce the spread of stomach ulcers?
They are spread by drinking contaminated water (oral transmission).
- having clean water supplies
- hygienic living conditions
Why are viruses said to be dependant on their hosts?
They need to infect host cells in order to reproduce and survive
Describe the basic structure of a typical virus
A typical virus has a strand of genetic material contained within a protein coat
Describe how viruses reproduce by the lytic pathway
- the virus attaches itself to a specific host cell and injects its genetic material into the cell
- the virus can then replicate its genetic material and reproduce the components of new viruses using proteins and enzymes
- once they’ve been produced, the viral components assemble
- the host cell gets split open releasing new viruses which infect more cells
Suggest why the human genome contains viral genetic material?
The presence of viral genetic material could have been caused by viruses reproducing by the lysogenic pathway. This involves viruses injecting their genetic material, which is then incorporated into the genome of a host cell
One way that the human body tries to fight a viral infection is by destroying cells within the body that are infected by the virus. Suggest how this might help to fight the virus.
By destroying cells infected with the virus it can prevent the virus from completing its cycle and producing new viruses. This helps to reduce the number fo viruses in the body that can infect new cells.
What pathogen causes chlamydia?
Bacterium
What cells in the body are killed by HIV?
White blood cells
How can HIV be spread?
The exchange of bodily fluids:
- sharing of needles between drug users
- sexual contact
Ways of reducing the spread of HIV:
- using condoms when having sex
- drug uses avoiding sharing needles
- using medication (to reduce the risk of passing the virus on to others during sex or infected mother passing the virus to their baby during pregnancy)
Ways of reducing the spread of chlamydia:
- wearing a condom during sex
- screening individuals so they can be treated
- avoiding sexual contact
Explain why someone infected with AIDS is very vulnerable to being infected with other pathogens?
AIDS causes an infected person’s immune system to deteriorate and eventually fail. As a result they are less able to fight off infections from other pathogens
Physical barriers that protect plants from pests and pathogens:
- waxy cuticle
- cell walls
Two types of chemical responses used by plants:
- some plants produce antiseptics to kill bacteria and fungal pathogens
- some produce chemicals that deter insects from eating their leaves
Describe how one chemical produced by a plant is used in medicine
- quinine has been used to treat malaria
- aspririn used to relive pain an fever
Some trees in a forest are infected by an unknown pathogen. The infected trees are randomly distributed throughout the forest. What does this suggest about how the pathogen is spread?
-suggests the pathogen is airborne and spread by the wind
How could you test in a field whether the symptoms shown by a plant are caused by nutrient deficiency rather than a pathogen?
- add nutrients to soil
- check for any change in plant’s symptoms
- if plants health improves its likely to have been nutrient deficient rather than infected by a pathogen
Why would testing plant tissue for the presence of specific antigens help to determine whether the plant is infected with a disease?
- antigens found on the surface of school plan are unique to each pathogen
- if antigens from a particular pathogen are detected in the plant tissue it show that the plant is infected by that pathogen