B6.3 Monitoring and maintaining health

Question 1

What is the definition of a disease?

Answer 1

A condition caused by any part of the body not functioning properly - can be mental or physical

Question 2

What is good health?

Answer 2

Not having any type of disease

Question 3

What is a communicable disease?

Answer 3

• can be spread between organisms - (AKA contagious / infectious disease)
• caused by pathogens (e.g. viruses, bacteria, fungi, Protozoa)

Question 4

What is a non-communicable disease?

Answer 4

• can’t spread between organisms

- caused by poor diet, genetic disorders, obesity

Question 5

What is epidemiology?

Answer 5

Branch of medicine which deals with incidence, distribution and possible control of diseases

Question 6

Factors affecting spread of communicable disease

Answer 6

• close contact individuals - e.g. schools, hospitals
• poverty
• hygiene
• education

Question 7

Preventing spread of communicable diseases in humans

Answer 7

• inhalation - cover mouth/nose when cough/sneeze
• cuts/bites to skin - protection from animal bites (insect repellent) - dont share needles
• food & drink - wash hands before - cook food thoroughly - drink clean water
• sexual inter course - use protection

Question 8

Spread of disease in plants

Answer 8

• through soil/water in which plants grow
• insect vectors (carriers)
• wind - blows fungal spores between plants
• direct contact - sap from infected plant transferred to healthy plant by tools/feeding animals

Question 9

Preventing spread of communicable diseases in plants and animals

Answer 9

• burn diseased plant
• avoid moving animals around
• clean tools/machinery
• chemical dips on farms to avoid spread of pathogens on feet
• kill infected animals if untreatable
• vaccinate animals/treat with drugs
• spray plant with fungicide
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Question 10

Monitoring the spread of a communicable disease

Answer 10

E.g. Ebola - the disease is monitored regularly over a short period

Question 11

Monitoring the spread of a non-communicable disease

Answer 11

E.g. lung cancer - the disease will be monitored over a long period of time with many cases

Question 12

In good conditions bacteria divide every…

Answer 12

…20 minutes - this is exponential growth

Question 13

What are physical plant defences?

Answer 13

barriers that prevent entry of microorganisms

• e.g. cellulose cell walls - structural barrier
• waxy cuticle layer - stops pathogens coming into contact with epidermal layer

Question 14

What are chemical plant defences?

Answer 14

Chemicals secreted by the plant that kill microorganisms

-e.g. anti fungal and antibacterial compounds

Question 15

Identifying plant disease in the field

Answer 15

• Observation - look for visual symptoms - e.g. mottled leaves & rotten fruit
• microscopy - finds pathogen responsible for disease (can normally be identified using light microscope but sometimes needs electron microscope is needed)

Question 16

Identifying plant disease in the lab - DNA analysis

Answer 16

• DNA analysis/fingerprinting - each plant pathogen has a unique set of DNA (genome) which produces a unique pattern/DNA profile (e.g. barcode)

Question 17

Identifying plant disease in the lab - identifying antigens

Answer 17

• identifying antigens - antigens are proteins found on surface of cells - each pathogen has specific antigens which can be used to identify them - diagnostic kits can be used by farmers to identify common crop pathogens

Question 18

What’s is the advantage of lab techniques over field ones?

Answer 18

Can identify plant pathogen before it causes significant damage to crop - in field, disease can only be identified once symptoms are apparent (disease has already taken hold)

Question 19

What are non-specific body defences?

Answer 19

• non-specific as prevent entry of all microorganisms

Question 20

First lines of defence (non-specific body defences)

Answer 20

• saliva & tears - antibacterial enzymes
• skin - prevents entry
• stomach acid - low pH kills harmful microbes

Question 21

What is the incubation period of a disease?

Answer 21

• time delay between a pathogen entering your body and you feeling unwell - pathogens grow + reproduce rapidly (causes damage to cells) - some pathogens produce toxins which cause symptoms such as fever + rashes

Question 22

What is the skin?

Answer 22

Main barrier to infection but if broken, pathogens can enter the body

Question 23

Why do scabs form?

Answer 23

Form to prevent pathogens entering the body and to prevent blood loss

Question 24

What are platelets?

Answer 24

Small fragments of cells made in bone marrow

• have no nucleus
• help blood to clot at site of a wound