Chapter 5 - Summary Questions

Question 1

Describe the difference between a communicable disease and non-communicable disease and a non-communicable disease and give one example

Answer 1

communicable – caused by pathogens and can be passed from one individual to another
e.g., cold, TB, HIV/AIDS

non-communicable – do not involve pathogens and cannot be passed from one individual to another
e.g., heart disease, arthritis, many cancers

Question 2

Give three factors that can effect the health of a person?

Answer 2

diet
stress
life situation/specific life situation, e.g., gender, access to health care

Question 3

How can diet affect the health of an individual?

Answer 3

diet – if a person does not have enough to eat they may suffer from deficiency diseases such as rickets and if they have too much to eat they may suffer from diseases linked to obesity such as type 2 diabetes

Question 4

How can stress affect the health of an individual?

Answer 4

stress – too much stress can lead to problems such as an increased risk of heart disease or mental health problems

Question 5

How can life situation affect the health of an individual?

Answer 5

life situations – e.g., if there is poor sewage collection and treatment people will be at increased risk of diarrhoeal disease

Question 6

Often a disease is the result of several different factors interacting.
Explain how these interactions can work giving three examples

Answer 6

any three from:
 Viruses living in cells can trigger changes that lead to cancers – for example, the human papilloma virus can cause cervical cancer.
Problems in the immune system mean it may not work effectively, either as a result of your genetic makeup, poor nutrition, or infections such as HIV/AIDS. This means you will be more likely to suffer from other communicable diseases
 Immune reactions initially caused by a pathogen, even something like the common cold, can trigger allergies to factors in the environment. These allergies may cause skin rashes, hives, or asthma.
 Severe physical ill health can lead to depression and other mental illness.
 Malnutrition is often linked to health problems including deficiency diseases, a weakened immune system, obesity, cardiovascular diseases, type 2 diabetes, and cancer

Question 7

As well as human diseases, we also study plant diseases caused by pathogens.
Suggest reasons why plant diseases are so important to human well-being
5 marks

Answer 7

• plants form the basis of human diets and feed the animals we eat
• if plants are damaged or destroyed by diseases, it can reduce human food supply
• starvation/malnutrition through lack of food can cause non-communicable diseases in people and increase the risk of contracting communicable diseases
• so understanding plant diseases and how to prevent them can have a direct effect on human health and well-being.

Question 8

Explain how communicable diseases spread from one person to another?
4 marks

Answer 8

• by air – many fungal spores are carried in the air and cause plant diseases. Many human diseases are spread by droplet infection when tiny droplets expelled from the breathing system are full of pathogens which are breathed in by other people and infect them.
   by direct contact – some pathogens are spread from one plant or person to another when a healthy organism is in direct contact with an infected individual
   by water – fungal spores carrying plant diseases are often carried in splashes of water and many human diseases such as diarrhoea and cholera are spread by pathogens from the faeces being carried in the water and entering the body through the digestive system when the water is drunk.

Question 9

What steps can an individual take to reduce the spread of a communicable disease from one person to another?

Answer 9

hand washing after using the toilet or handling uncooked meat
 using disinfectants on kitchen work surfaces
 coughing into handkerchief, tissue or hands – then washing hands
 isolating infected individuals
 destroying or controlling vectors
 vaccination

Question 10

Suggest how companies and organisations can reduce the spread of a communicable disease between employers

Answer 10

have plenty of space so people are not working too closely together to reduce spread of pathogens
provide good toilet and washing facilities
provide tissues
encourage people to take time off if they are ill so they don’t spread diseases

Question 11

What is the difference between HIV and AIDS?

Answer 11

HIV is virus that causes disease AIDS

Question 12

State three different types of plant diseases?

Answer 12

black spot
 chlorosis
 nitrate deficiency
 crown gall
 root knot disease
 magnesium deficiency
 tobacco mosaic virus

Question 13

Explain how the disease might effect the yield of a crop?

Answer 13

damage to leaves prevents photosynthesis and so limits growth
 damage to roots prevents uptake of water and so limits growth
 damage to flowers prevents pollination which therefore prevents reproduction

Question 14

List three ways farmers can help to protect their crops from plant diseases.

Answer 14

• good field hygiene
• keeping plants well apart
• controlling insect pests to prevent spread of pathogens
• planting disease-resistant strains

Question 15

Explain why research into the prevention of plant diseases is so important to human health and well being?

Answer 15

• crop protection measures can protect crop yields (particularly cotton, potatoes, rice, and maize).
• improved crop yields provide economic stability
  (reducing impact on human health of diseases associated with poverty)
• therefore reduce risk of food shortage and starvation
  (communicable diseases more dangerous and prevalent in starving populations)