SB5 - Health, Disease and the Development of Medicine ✓ Flashcards Preview

Edexcel GCSE Biology (9-1) > SB5 - Health, Disease and the Development of Medicine ✓ > Flashcards

Flashcards in SB5 - Health, Disease and the Development of Medicine ✓ Deck (50)
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SB5a - What are the three type of health?

  • Physical well-being: Being free from disease, getting regular excersize, limiting harmful substance etc.
  • Mental well-being: How you feel about yourself
  • Social well-being: How well you get along with others


SB5a - What is the difference between communicable and non-communicable diseases?


  • Caused by pathogens (microorganisms athat cause disease)
  • Can be spread between people
  • Localised cases


  • Caused by problems in the body and by lifestyle choices
  • Cannot be spread between people
  • Widely spread cases


SB5a - Why may a person be more likely to catch a disease if they've already got one?

  • One disease damages the immune system, making it easier for other pathogens to cause disease
  • A disease can damage the body's natural physical and chemical defences making it easier for pathogens to get in
  • A disease can stop an organ from functioning correctly, meaning other diseases are mroe likely to occur


SB5b - Define malnutrition.

A lack or excess of a specific nutrient in the body


SB5b - Describe the defficiency diseases associated with lack of:

  1. Protein
  2. Vitamin C
  3. Vitamin D and/or Calcium
  4. Iron

  1. Kwashiorkor: enlarged belly, small muscles, failure to grow properly
  2. Scurvy: Swelling/bleeding gums, muscle/ joint pains and tiredness
  3. Rickets/Osteomalacia: Soft bones/cruved leg bones
  4. Anaemia: Less and smaller red blood cells, tiredness


SB5b - How do you calculate BMI?

mass / height ^2


SB5b Why is drinking too much alcohol dangerous?

  • Ethanol is poisonous to cells
  • When absorbed from the gut, it passes to the liver to be broken down. So liver cells are more likely than other cells to be damaged, leading to liver disease e.g cirrhosis


SB5b - Why is ethanol (in alcohol) considered a drug and what disease can it lead to?

  • It's considered a drug because it changes the way in which the body works
  • It can lead to liver cirrhosis which is a disease where the liver doesn't function properly


SB5c - What is heart bypass surgery?

  • This is when a new blood vessel is inserted to 'by-pass' a blocked artery


SB5c - Describe how smoking can lead to blood clots.

  • Tobacco from smoking will damage artery linings.
  • Fat (or plaque) can build up in the artery wall making the artery narrow.
  • This will increase blood pressure
  • Eventually, the fat will block the whole artery
  • White blood cells will form a wall around this causing a clot leading to a heart attack or stroke


SB5c - Explain how a stent works.

  • A stent is a small mesh inserted into the artery on a delfated balloon.
  • Once in place, the balloon is inflated and the stent expands widening the artery
  • The balloon is taken out but the stent stays in keeping the artery wide


SB5c - What is BMI and what are its pros and cons?

  • A measure of weight relative to height calculated by mass ÷ height².
  • Its good at being a a measurement and comparison between people helping identify if they're over/underweight or obese etc.
  • However it doesn't take into account varying muscle and bone mass and so isn't always an accurate way of assesing risk.


SB5c - What is CVD?

Cardiovascular disease is a result of the circulatory system functioning poorly and can lead to many side effects including high blood pressure, heart pains and even heart attacks


SB5c - Why is an obese person at a higher risk of developing CVD?

Obese people are more likely to have more body fat. More body fat increases risk of CVD


SB5d - Describe and explain the causes, types of pathogen, host organisms and symptoms associated with:

  1. Cholera
  2. Tubercolosis(TB)
  3. Chalera dieback

  1. Caused by vibrio cholera (bacteria). It's hosts are animals/humans and it can lead to severe diarrhea and dehydration
  2. Caused by mytobacterium tubercolosis (bacteria). It's hosts are humans/animals. It damages lung tissue leading to coughing fever and tiredness 
  3. Caused by the fungus chalara and affects trees/plants. Lesions on trunks and leaves die earlier than usual


SB5d - Describe the type of pathogen, host organisms and symptoms associated with:

  1. Malaria
  2. Ebola
  3. Ulcers

  1. Caused by the plasmodium protist, it infects humans using moquitoes as a vector. Leads to fever weakness, sickness and lack of red blood/liver cells
  2. Caused by the ebola virus. It causes haemorrhagic fever. 
  3. Caused by the heliobacter pylori bacteria, causing stomach ulcers, pain nausea and vomiting. 


SB5d - Why are people with HIV likely to develop AIDS?

  • HIV attacks the white blood cells in your immune system making it weak.
  • Thus the immune system is inable to defend the body from secondary infections effectively


SB5d - Why are viruses not 'true organisms'?

They don't have a cellular structure and require hosts to survive


SB5e - State how the pathogen is spread and 1 way to prevent the spreading of this pathogen

  1. cholera
  2. tubercolosis
  3. malaria
  4. stomach ulcers
  5. ebola
  6. HIV

  1. water - boil water to kill bacteria prior to drinking
  2. airborne - ventilate buildings to reduce chance of breathing in bacteria in droplets of mucus coughed out by an infected person
  3. mosquito vector - prevent mosquitos biting people by keeping them off skin
  4. orally - cook food thoroughly to kill bacteria 
  5. body fluids - quarantine infected people
  6. sexual fluids - use condoms


SB5f - Describe the lysogenic cycle.

  • The virus injects it's genetic material into the host cell
  • The injected genetic material is incorporated into the DNA of the host cell
  • The viral genetic material gets replicated along with the host DNA every time the host cell divides - but the virus is dormant and no new viruses are made.
  • Eventually a trigger causes the viral genetic material to leave the genome and enter the lytic pathway


SB5f - Describe the lytic cycle.


  • Virus attaches to the host cell and injects its DNA into the cell
  •  Virus copies itself and causes new proteins to be made, using the organelles in the host cell
  •  DNA and Viral proteins are packaged together to form new viruses.
  •  New viruses are released from the cell, which usually destroys it.
  • The new viruses are free to infect more cells



SB5g - What are the chemical defences of a plant (giving examples where appropriate)?

  • Poisons (in foxgloves)
  • Natural insect repellents/alarm substances (Wild potatoes)


SB5g - What are the physical defences of plants?

  • Waxy layer called the cuticle
  • Cell walls


SB5h - How are keys used to identify plant diseases?

Farmers comare visible symptoms on infected plants to pictures to try and deduce which disease the plant has


SB5h - How is diagnostic testing used to identify plant diseases?

  • Farmers will send off a sample of the infected plant to a lab where they will run tests to work out what the pathogen is.
  • They may also send soil samples to test for nutrients and toxins.
  • This can be very expensive.


SB5h - What is a distribution analysis?

  • This is the study of the pattern of where diseased plants occur to help identify the cause

  • By using other information such as wind direction, you can deduce how the disease has spread and figure out what the disease is.


SB5h - Which two methods may a farmer use to identify plant diseases?

  • Keys
  • Distribution analysis
  • Diagnostic testing


SB5i - What are physical and chemical barriers?

  • Barriers to prevent pathogens from infecting the body.
  • Physical barriers stop them getting in and chemical barriers stop them from being effective.


SB5i - What are the physical and chemical barriers in the body?

Chemical Barriers

- Lysozyme enzyme in tears kills bacteria by digesting their cel walls
- Hydrochloric Acid in stomach kills pathogens in food and drink

Physical Barriers

- Unbroken skin is too thick for most pathogens to pierce
- Sticky mucus in the breathing passages and lungs trap pathogens
- Cilia on the cells lining the lungs waft mucus and trapped pathogens back up the throat where it can be swalloed


SB5i - What is lysozyme?

  • Lysozyme is an enzyme screted by skin and in tears and saliva.
  • It is chemical defence that breaks down the cell walls of types of bacteria.