B6.3 - Part 1 Monitoring and maintaining health

Question 1

What is disease?

Answer 1

A condition caused by any part of the body not functioning properly, causing mental and/or physical effects.

Question 2

What is the different between communicable and non-communicable disease?

Answer 2

• Communicable diseases are diseases that can be spread between organisms - infectious or contagious disease
• Non-communicable diseases are diseases that cannot be spread between organisms

Question 3

Define health

Answer 3

A state of complete physical, mental and social well-being (as defined by the WHO)

Question 4

What is a pathogen?

Answer 4

A microorganism that causes disease.

Question 5

Name four type of pathogen.

Answer 5

1. Fungi
2. Bacteria
3. Virus
4. Protozoa

Question 6

Why are people with HIV more likely to catch tuberculosis?

Answer 6

HIV causes AIDs which weakens their immune system making them more susceptible to infection with tuberculosis and other infections.

Question 7

What can HPV lead to?

Answer 7

HPV can lead to certain types of cervical cancer.

Question 8

How can pathogens be spread between animals?

Answer 8

• Droplet infection - respiratory system, inhaling pathogens
• Eating contaminated food or drink - digestive system
• Through cuts in the skin
• Sharing needles
• Direct contact
• Sexual intercourse

Question 9

How can pahtogens spread between plants?

Answer 9

• Vectors such as insects
• Wind - fungal spores blown
• Direct contact with sap of infected plant

Question 10

Name three ways the spread of animal disease can be reduced?

Answer 10

• Covering mouth/nose when coughing/sneezing
• Not touching infected people of objects
• Using protection - protective suits, masks, shields, condoms
• Not sharing needles
• Hand washing
• Cooking food properly
• Drinking clean water
• Insect repellent / nets

Question 11

Name four mehtods of prevening diesease in plants and animals used in farming.

Answer 11

1. Burning dieseased plant material
2. Herd slaughtering - BSE, foot and moth diseasw
3. Drugs & isolation of diseased animals
4. Movement/transport bans upon diesease animals
5. Chemical dips to kill pathogens upon aminals and footwear
6. Vaccination programs
7. Fungicides
8. Pesticides

Question 12

Name one bacterial disease that affects humans.

Answer 12

• Samonella. Found in raw meat, eggs, unwashed raw vegetables and unpasturised milk. Transimmted by ingesting infected food. Symptoms = fever, sickness and diarrhoea
• Campylobacter. Found in raw meat, unpasturised milk and untreated water. Transimmted by ingesting infected food. Symptoms = fever, sickness and diarrhoea
• E.Coli. Found in raw and undercooked meat, unpasturised milk and dairy products. Transimmted by ingesting infected food. Symptoms = fever, sickness and diarrhoea
• Chlamydia. Sexually transmitted. Pain when urinating, discharge from penis or vagina.
• Gonorrhoea. Sexually transmitted. Pain when urinating, discharge from vagina.

Question 13

Describe one bacterial disease that affects plants.

Answer 13

• Crown gall disease (Agrobacterium tumefaciens)
• Transmitted through cuts in the stems of plants.
• Plants display tumor type growths
• Tumours encircle stem/trunk cutting off flow of sap.

Question 14

Describe one viral disease that affects humans.

Answer 14

• Human Immunodeficiency Virus (HIV) - Transmitted through bodily fluids and commonly spread through sexual activity. Symptoms include rash and fever like symptoms (intial), invades immune cells preventing them from producing antibodies, leading to AIDs.
• Human Papilloma Virus (HPV) - Transmitted through bodily fluids and commonly spread through sexual activity. Symptoms include genital warts, throat warts, cancers of the genitals, head, neck, and throat.

Question 15

Describe one viral disease that affects plants.

Answer 15

• Tobacco Mosaic Virus
• Transmitted through direct contact
• Symptoms include spots and a yellow coloured masaic pattern.

Question 16

Describe one fungal disease that affects animals.

Answer 16

• Athletes foot
• Transmitted through driect contact or contact with skin particles (on shared towels/socks/shoes)
• Dry crack skin between the toes

Question 17

Describe one fungal disease that affects plants.

Answer 17

• Erysiphe graminis (barley podery mildew)
• Transmitted through vectors like aphids in cold damp environments
• Symtpoms include powdery growth and yellowing on the opposite side of the leaf

Question 18

Name two physical plant defences against disease.

Answer 18

• Thick cell wall
• Waxy cuticle

Question 19

How do plants use chemical defences to prevent diesase?

Answer 19

• Insect repellents to repel insect vectors e.g. pine resin & citronella
• Insecticides e.g. pyrethrins made by chrysanthemums
• Antibacterial compounds e.g. phenols which disrupts bacterial cell walls & defensins which disrupts bacterial cell membranes
• Antifungal compounds e.g. chitinases which breakdown fungal cell walls and caffeine which is toxic to fungi and insects.
• Antimicrobial chemicals e.g. cyanide production when plant cell attacked

Question 20

State three ways palnt disease can be identified.

Answer 20

• Analysis DNA to see whether the plant contains any pathogen DNA
• Antigen detection to find any foreing antigens present in the plant
• Obervation of symptoms
• Microscopy

Question 21

What is the function of platelets?

Answer 21

Platelets are small fragments of cells that are involved in blood clotting.

Question 22

How does a scab form?

Answer 22

• Skin is cut and starts to bleed
• Platelets change the blood protein fibronogen into fibrin which is fiberous.
• Fibrin forms a network of fibres in the cut
• Red blood cells are trapped in the fibre to form a clot
• The clot hardens to form a scab.

Question 23

State the human bodies defence mechanisms against microorganisms.

Answer 23

• Skin - Physical barrier. Sweat glands produce oils the help to kill microorganisms
• Scabs - prevent microorganisms entering via wounds
• Stomach acid - low pH kills pathogens
• Cillia & mucas in airways - trap & waft
• Nasal hairs
• Tears - lysozymes
• Earwax
• White blood cells - phagocytes & lymphocytes

Question 24

What is the function of white blood cells.

Answer 24

• Phagocytes are involved in phagocytosis - engulfing pathogens and then making enzymes that digest the microorganism (non-specific)
• Lymphocytes make antitoxins or antibodies (specific)

Question 25

What are antibodies?

Answer 25

• Proteins found on the surface of lymphocytes that bind to antigens upon the surface of microorganism
• Once bound the pathogen can be engulfed by a phagocyte cell
• Each antibody only binds to one type of antigen
• New antibodies must be made by lymphocytes every time a new type of microorganism enters the body (primary response)
• WBCs are able to make the same antibodies more quickly if infection occurs again (secondary response)

Question 26

What are monoclonal antibodies?

Answer 26

Laboratory generated antibodies used in diagnositcs and treatment.

Question 27

How are monoclonal antibodies produced?

Answer 27

• Genetically modified mice are injected with antigens
• The mouse produces an immune response producing lymphocytes with antibodies specific to the antigen
• The antibody prodcuning lymphocytes are collected and fused with myeloma (cancer) cells from the bone marrow
• The fused cell is called a hybrioma.
• The hybridoma grows rapidly forming clones which produce the antibody.
• The antibody is harvested = monoclonal antibodies.

Question 28

Name three uses of monoclonal antibodies.

Answer 28

1. Pregnancy tests
2. Detection of cancerous tissue
3. Drug delivery to cancer cells
4. Identificaton of pathogens
5. Drug testing

Question 29

What is the difference between anitbiotic and antivirals?

Answer 29

• Antibiotics kill bacteria
• Antivirals inhibit the reproduction of viruses

Question 30

What are antiseptics?

Answer 30

Substances applied external to the body to kill pathogens.

Question 31

How do vaccines work?

Answer 31

• Dead or inactive pathogens are injected into the body
• The antigens in the vaccine stimule lymphocytes to make antibodies against the pathogen
• The antibodies lead to the destruction of antigens without risk of you getting the disease.
• Memory cells are created to provide long term immunity

Question 32

What is the ‘halo’ around discs of bacterial growth called, caused by antibiotics.

Answer 32

Zone of inhibition.

Question 33

What is aseptic technique?

Answer 33

An approach to working, which prevent cross-contamination from unwanted microorganisms.

Question 34

State three important steps when culturing microorganisms in the laboratory?

Answer 34

• Clean surfaces with alcohol
• Wear gloves
• Autoclave glassware and apparatus before and after use
• Keep the culture closed until it is needed
• Use a bunsen burner to sterilise wire loop
• Work close to the bunsen flame

Question 35

What are the stages in the development of new medicines?

Answer 35

• Research the drug and test it upon lab grown cells
• Test the drug upon animals - data from two animal species required in the UK before testing upon humans
• Clinical trial 1 - test upon healthy volunteers
• Clinical trial 2 - test upon a small sample of people with the disease
• Clinical trial 3 - test upon a large number of people with the disease
• If all stages passed approval granted by the MRHA
• Continued studies undertaken after approval to monitor side effects

Question 36

What is the 3 R’s principle?

Answer 36

• Reduction - smallest number of animals possible
• Refinement - improving experiements to avoid unnecessary suffering and improve animal care
• Replacement - where possible, replacing animals with other techniques e.g. cell cultures or computer models