Health, Disease And The Development Of Medicine

Question 1

Define health

Answer 1

A complete state of physical, mental and social wellbeing

Question 2

Describe the difference between communicable and non-communicable diseases

Answer 2

Communicable diseases can be passed on from one person to another, Non-communicable can not.

Question 3

Explain why a person with HIV is more likely to become infected with AIDS than a healthy person.

Answer 3

HIV severely weakens a persons immune system by destroying white blood cells, leading major vulnerability to AIDS

Question 4

Describe a pathogen and give 4 examples

Answer 4

A micro-organism which causes disease. These include bacteria, fungi, viruses and protists

Question 5

Describe which type of pathogen each one of the following is, and provide a symptom for each:

A)Tuberculosis
B)Chalara Ash Dieback
C) Malaria
D)HIV

Answer 5

A) Bacteria, coughing up blood
B) Fungi, leaf loss and bark lesions
C) Protists, fever
D) Virus, flu like illness

Question 6

Explain how the following pathogens are spread and how this spread can be reduced or prevented:

A)Tuberculosis
B)Chalara Ash Dieback
C)Malaria
D)HIV

Answer 6

A) Airborne disease, vaccination
B) Airborne disease, removing and disposing of infected ash plants
C) Animal vectors (Mosquitoes), use insect repellent on exposed skin.
D) Sexual intercourse, wear condoms before intercourse

Question 7

Describe the lytic cycle

Answer 7

The virus uses its protein spikes to pierce into the host cell.
Next, the virus injects its DNA into the cell, forming new parts for the virus.
Then, these parts assemble into new viruses. This keeps happening.
Finally when the cell can hold no more, the cell bursts (Cell lysis) releasing the virus particles into the host organism to infect more cells

Question 8

Describe the lysogenic cycle

Answer 8

The virus uses its protein spikes to pierce into the host cell.
Next, the virus will inject its DNA into the host cell. Here, it will combine with the host’s DNA. Now the host cell will divide and replicate, each cell containing the viral genetic material.

Question 9

Explain how the bacteria chlamydia is spread and how it can be prevented

Answer 9

Spread through sexual contact, don’t have sexual actions (Anal, vaginal, oral)

Question 10

Describe and explain 2 physical barriers plants have against pathogens

Answer 10

A waxy cuticle covers leaves, prevents their cells from being infected by bacteria/fungi.
A cell wall, prevents a pathogens contact with sub cellular structures.

Question 11

Describe a chemical defence some plants have against pests/pathogens

Answer 11

Produce antiseptics, which kill bacteria and fungi. They also produce chemicals to deter pests from feeding on their leaves

Question 12

Explain a chemical made by plants which humans use to treat disease

Answer 12

Aspirin, found in bark and leaves of willow tree. Can be used to relieve pain and fever

Question 13

Describe 2 ways plant diseases can be detected

Answer 13

1.observing changes to the plant in a different environment
2. Detecting pathogen DNA on a plant

Question 14

Describe 2 physical barriers humans have against pathogens. Explain each.

Answer 14

1.Cilia,tiny hairs in the throat to catch mucus going down, so it can be brought up the throat and coughed out.
2. Skin, blood clots form when it is cut to avoid microorganisms getting inside

Question 15

Describe 2 chemical barriers humans have against pathogens. Explain each.

Answer 15

1 Lysozymes, chemical produced by the eye to kill bacteria on the surface of the eye.
2. Hydrochloric acid, kills pathogens which are swallowed.

Question 16

Explain how pathogens are dealt with by the immune system

Answer 16

After a pathogen enters the immune system, the pathogens have antigens on their surface. These antigens trigger an immune response, which is the production of antibodies. These antibodies will kill the pathogen.

Question 17

Describe when memory lymphocytes are made and explain their role in a secondary immune response

Answer 17

Whilst antibodies are made to fight against a pathogen, memory lymphocytes are also produced. Their role in a secondary immune response is that if the same pathogen re enters the body, these memory lymphocytes will remember the pathogen and be able to deal with it extremely quickly

Question 18

Explain an immunisation using an inactive form of a pathogen

Answer 18

They are a weakened or deactivated form of a pathogen to trigger protective immunity to it.

Question 19

Describe an advantage of immunisation, and explain what it is.

Answer 19

Herd immunity is when a large number of the population are immunised against a disease. This means even people who are not immunised have less chance of catching the disease, as there are less people (the immunised) to pass it on.

Question 20

Explain a disadvantage of immunisation

Answer 20

It doesn’t always work, and some people may have a bad reaction to them (like fevers). However this is very rare.

Question 21

Why can antibiotics not be used against viruses. Give 2 reasons

Answer 21

Viruses reproduce using our body cells, meaning it is extremely difficult to develop drugs which destroy the virus without harming our body cells.
Viruses don’t have cell walls, so antibiotics can’t attack them

Question 22

How do antibiotics kill bacteria

Answer 22

They prevent the developing processes in the bacterial cells by attacking their cell walls, as well as not affect the host cells in the process.

Question 23

During an investigation of bacteria growth on Agar Jelly, state 3 aseptic techniques that should be used to ensure accurate results.

Answer 23

1. Use an autoclave (High pressure steam machine) to sterilise the Petri dish.
2. Before transferring bacteria using an inoculating loop (wire loop), run it through a hot flame, so that unwanted micro-organisms are killed.
3. Cover the completed Petri dish with a lid which is lightly taped on. This ensures no micro-organisms from the air enter the Petri dish.

Question 24

What is the formula to calculate cross-sectional areas of bacterial cultures and clear
agar jelly

Answer 24

Pi x radius squared

Question 25

From the investigating the effect of substances on bacterial growth practical, explain what the zone on inhibition is

Answer 25

Area where non resistant bacteria dies, shown as clear in colour.

Question 26

Where do each of these kill bacteria:

A) Antiseptics
B) Antibiotics

Answer 26

A) Outside the body (Skin)
B) Inside the body

Question 27

Demonstrate a step by step guide of the practical:

Investigating the effect of substances on bacterial growth (6)

Answer 27

1. Place 3 paper disks in an agar jelly plate, with 2 soaked in different antibiotics, and one soaked in NOTHING. Place all on the SAME agar plate, with an even coating of bacteria. Leave space between the disks.
   2.The antibiotics (which were soaked on 2 of the paper disks) should diffuse into the agar jelly. Antibiotic resistant bacteria will grow around the paper disks, but non resistant bacteria will die. Where the bacteria has died there will be clear areas around the disks (Zone of inhibition).
2. Leave the plate for 48hrs at 25 degrees Celsius.
3. The more effective antibiotic will have a larger zone of inhibition.

Question 28

Describe the production of monoclonal antibodies
(4)

Answer 28

1.A mouse is injected with the chosen antigen
2.Take the B-lymphocytes from the mouse (which will have the antibodies for the antigen)
3.Fuse the B-lymphocytes with myeloma cells (tumour cells)
4.This forms a hybridoma cell
5.This divides quickly to produce many clones with the same antibodies.

Question 29

Explain the use of monoclonal antibodies in pregnancy testing. (6)

Answer 29

1. The hormone HCG is present in the urine of pregnant women
2. The part of the stick where the woman would urinate has antibodies to the hormone, with BLUE beads attached.
3. At the end of the stick is strip with more of the antibodies attached.
4. If a pregnant woman urinates on the stick, the HCG would bind to the antibodies at the start of the strip.
5. The urine would move up the stick, carrying the hormone as well as the blue beads
6. The beads and hormone would bind to the antibodies on the end of the strip. The beads then would turn the strip blue, indicating a positive test.

Question 30

Describe 2 advantages of monoclonal antibodies on cancer.

Answer 30

1. You can locate the position of blood
   clots and cancer cells.
   2.They can treat cancer

Question 31

Why are monoclonal antibodies a better use to treat cancer than radiotherapy and drug use.

Answer 31

They only target the specific cancer cells, meaning no body cells are harmed in the process.

Question 32

Describe 3 ways you can attain non-communicable diseases

Answer 32

1. Cardiovascular disease
2. Cancer
3. Nutrition related disease (Type 2 diabetes)

Question 33

What is the BMI calculation

Answer 33

mass divide height squared

Question 34

How does smoking cause cardiovascular diseases. Give 2 reasons

Answer 34

Nicotine in cigarettes is highly addictive, as well as increasing heart rate and blood pressure.
Increase risks of blood clots, which can restrict blood flow, leading to heart attacks.

Question 35

What is the waist to hip calculation

Answer 35

waist diameter divide hip diameter

Question 36

Explain why alcohol can cause liver disease

Answer 36

Liver cells can be damaged by long term mis-use, and lose their ability to re-generate. This can lead to cirrhosis.

Question 37

Explain 3 treatments for cardiovascular disease.

Answer 37

Stents, a surgical procedure. Tubes are inserted into clogged arteries, making the diameter of the lumen increase, allowing free blood flow.
Statins, drug use. Reduces amount of cholesterol in the blood stream. This slows the rate of fatty build in arteries, reducing the risk of heart attacks.
Healthy, balanced diet, a lifestyle choice. Eating less saturated fats decreases cholesterol levels