Health and disease

Question 1

What is health?

Answer 1

state of complete physical, mental and social wellbeing

Question 2

what’s a disease?

Answer 2

condition where part of an organism doesn’t function

Question 3

What’s the difference between a communicable and a non communicable disease?

Answer 3

a communicable disease can be transmitted by individuals but non communicable cannot

Question 4

How does a presence of one disease lead to a higher susceptibility of other diseases?

Answer 4

• if you are affected by one disease it damages your immune system and allows pathogens to enter and attack more easily
• can damage body’s natural barriers and defenses
• stops organ systems functioning properly which makes diseases more likely to occur.

Question 5

Describe a pathogen and give examples

Answer 5

a microorgaism that causes diseases.
- bacteria
- fungi
- protist
- viruses

Question 6

How do pathogens spread?

Answer 6

• direct contact : touching contaminated surfaces
• airborne : pathogens are carried in air and breathed (tiny droplets we cough and sneeze)
• waterborne : drinking / coming in contact with water

Question 7

How to limit the spread of pathogens?

Answer 7

• improve hygiene : handwash and use disinfectants and clean cutlery
• remove contact : isolate from infected individuals
• remove vectors : use pesticides/insecticides and remove their habitats
• vaccination : inject small amounts of harmless pathogens so individual becomes immune which stops spread

Question 8

What are diseases caused by bacteria?
State
i) symptoms
ii) prevention

Answer 8

cholera
- symptoms : diarrhea
- spread : through contaminated water
- prevention : access to clean water

tuberculosis
- symptoms : coughing and lung disease
- spread : airborne or by infected individuals
- prevention : keep rooms well ventilated and have good hygiene

helicobacter
- symptoms : stomach ulcers
- spread : oral transmission
- prevention : clean water

Question 9

What are diseases caused by virus?
State
i) symptoms
ii) prevention

Answer 9

ebola
- symptom : haemorrhagic fever
- spread : bodily fluids
- prevention : isolate individual and sterilize infected areas.

HIV
symptoms : destroys white blood cells
spread : bodily fluids

Question 10

What’s a disease caused by protists?
State
i) symptoms
ii) prevention

Answer 10

malaria
- symptoms : damage to red blood cells and liver
- spread : mosquitos as vectors
- prevention : mosquito net and repellent

Question 11

What’s a disease caused by fungi?
State
i) symptoms
ii) prevention

Answer 11

chalara ash dieback
- symptoms : leaf loss and bark lesions
- spread : wind
- prevention : remove young infected trees and replace with new species and restrict import or movement of these trees

Question 12

What are viruses?

Answer 12

protein coats around strands of genetic material that infect living cells to reproduce

Question 13

Describe the virus life cycle including the lytic and lysogenic pathway.

Answer 13

Lytic pathway:
- virus attaches to host cell and injects its genetic material into it
- using proteins and enzymes of the host cell, (host of cell ) it replicates the viral DNA
- these assemble to form virus particles
- once host cell is full of virus particles it bursts and lysis which is ejected into the environment which infects even more cells

Lysogenic Pathway:
- injected genetic material is incoporated into the genome of the host cell
- host cell and genetic dna of virus is replicated but virus is dormant
- a trigger causes viral genetic material to leave genome and return to lytic pathway and cycle repeats

Question 14

How can STIs be spread and prevented?

Answer 14

Chlamydia
- bacterium that acts similar to virus (reproduces in host cells )
- causes infertility & painful urination
- prevention : reduced by wearing a condom, screening, or avoid sexual contact

HIV
- virus that kills white blood cells and later leads to AIDs
- which is when immune system deteriorates and eventually fails - person becomes vunerable to other pathogens
- spread : bodily fluids
- prevention : wear a condom, medication, screening and proper treatment.

Question 15

Describe how plants defend themselves against pests and pathogens using physical barriers.

Answer 15

• waxy cuticle : acts as a barrier which stops pathogens entering. also stops water collecting on leaf which reduces infections that are transferred through water
  -thick cellulose cell wall : impermable to many pathogens
• layer of bark : prevents pathogens reaching cells and tissues
• leaves close stomata : stops pathogens entering

Question 16

Describe how plants defend themselves against pests and pathogens using chemical barriers

Answer 16

• release antiseptics which kill bacteria and fungal pathogens
• produces chemicals which deter pests feeding on leaves by attracting larger insects that eat them
• some of these chemicals are used as drugs ( ex. aspirin relieves pain and fever which is a chemical found in leaves and bark of willow tree)

Question 17

identifying diseases in the field

Question 18

identifying diseases in the lab

Question 19

What are human physical barriers?

Answer 19

• skin : stops pathogens entering and protects tissues and cells underneath. if damaged. blood clots and seals cuts to keep pathogens out
• mucus : traps bacteria and pathogens entering before they reach the lungs
• cilia : wafts away mucus that’s trapped with pathogens which are then killed in stomach

Question 20

What are human chemical barriers?

Answer 20

hydrochloric avid - kills pathogens that are swallowed
- lysozyme : kills bacteria on eye surface

Question 21

What is the role of phagocytosis?

Answer 21

1) phagocyctes track down pathogens and binds to it
2 ) phagocyte’s membrane surrounds pathogen and engulfs it
3 ) enzymes inside phagocyte break down the pathogen in order to destroy it

Question 22

How does the immune system act as a defense against disease?

Answer 22

1) pathogen enters body with antigens on its surface
2) B-lympocytes find these antigens which releases antibodies
3) the specific complementary antibodies bind to the antigens, which makes it easier for WBCs to track and find them ( ex phagocytes)
4) antigens also trigger release of memory lympocytes remains in blood for long time
5) antibodies are produced rapidly and flow around body to find similar anitgens
6)

Question 23

What is the role of antitoxins?

Answer 23

bind with pathogens to neutralise the toxins they release

Question 24

how do memory lympocytes work

Answer 24

• they remember specific anitgens for a long time so they reduce the time needed to produce specific antibodies
  t-he rate of antibodies increases
• individual will no longer feel symptoms of illness as the secondary response got rid of the pathogen - immune

Question 25

what are 3 uses for monoclonal antibodies?

Question 26

describe the stages of antibiotic development that would occur after discovering an antibiotic

Question 27

describe an investigation of antibiotics & antiseptics (CORE PRACTICAL)

Question 28

describe a practical oj growing bacteria

Question 29

how do u investigate the effectiveness of growing bacteria

Question 30

what’s a risk factor?

Answer 30

increase likelihood that a person will develop certain disease
- a disease is caused by multiple risk factors interacting with each other

Question 31

what are 3 ways smoking increases chance of cardiovascular disease?

Answer 31

• nicotine increases heart rate : increases blood pressure
• high blood pressure damages artery walls : build up fatty deposits in artery restrict blood flow & increase risk of heart attack or stroke
• increases risk of blood clots forming in arteries : restrict / block blood flow -> heart attack / stroke

Question 32

what do we think of risk factors beignets?

Answer 32

• aspects of person’s lifestyle
• substances in body or environment

Question 33

what are other lifestyle factors that are associated with diseases?

Answer 33

• diet with too many / little nutrients : malnutrition (ex scurvy - vitamin c deficiency)
• not getting enough exercise & diet high in saturated fats and sugar :obesity which leads to obesity
• drinking too much alcohol : lung disease
  
  • alcohol is broken down by enzymes in the liver + some products are toxic. after a long period of drinking this can cause permanent liver damage

Question 34

how do you measure BMI?

Answer 34

BMI = mass / height^2

Answer 35

if you have high fat, sugar diet & don’t do enough exercise you take in more energy than you use which is stored as fat -> higher bmi & obese

Question 36

why is the BMI not always reliable?

Answer 36

athletes have higher muscle mass which weights more than fat
this leads to them having a high BMi suggesting they are overweight