B2 health and disease and how disease spreads

Question 1

What is a disease?

Answer 1

A condition that commonly damages the cells of the host and impairs the normal structures or functioning of an organism.

Question 2

Causes of disease (5)

Answer 2

Infected by pathogen
Mutation in organisms genes
Affected by environmental conditions (eg a plant gets insufficient light)
May experience trauma
Lifestyle

Question 3

What is a Communicable disease?

Answer 3

A disease that can be spread among organisms

Question 4

What causes communicable diseases?

Answer 4

Pathogens infecting the organism

Question 5

What is a pathogen?

Answer 5

A microorganism that causes disease

Question 6

Types of Pathogens (4)

Answer 6

Bacteria, viruses, fungi, protists

Question 7

What is a Non-communicable disease?

Answer 7

Cannot be passed from one organism to another.

Generally long lasting and progress slowly

Question 8

Non-communicable disease (4)

Answer 8

Cancer, diabetes, cardiovascular disease, respiratory disease

Question 9

What are the causes of Non-communicable diseases?

Answer 9

Associated with genetic mutations, lifestyle and environmental factors

Question 10

What is a symptom?

Answer 10

Changes in an organism that indicate a disease is present.

Question 11

Example of a symptom of Multiple Sclerosis

Answer 11

Temporary loss of vision

Question 12

What is an incubation period?

Answer 12

Time from infection to the show of symptoms

Question 13

What is the incubation period for chicken pox?

Answer 13

14 day for spots to appear

Question 14

What is HPV (Human Papillomavirus)?

Answer 14

Virus that effect the reproductive system

Doesn’t always cause symptoms often clears up on it’s own

Can cause cell Change resulting in the development of certain types of cancer.

Though that all cervical cancer are result from HPV infection

Question 15

What are Helminths?

Answer 15

A certain type of worms that causes disease if they get inside the body

Question 16

What is Trichinosis?

Answer 16

A disease that is caused by infection by the Helminth

It can reduce the development of some autoimmune diseases e.g. Crohns

Question 17

What is an autoimmune disease?

Answer 17

The immune system recognises the bodies own cells as foreign and attacks them.

Question 18

Bacteria

Answer 18

Very small (1/100 of the size of a body cell).
Reproduce rapidly
Produces toxins that damage the cells and tissues.

Question 19

Viruses

Answer 19

Not cells
Really tiny (1/100 the size of a bacterium)
Replicate inside the infected organism’s cells, the cell then burst releasing the viruses.

Question 20

Protists

Answer 20

Eukaryotic
Single celled
Vary in size

Question 21

Fungi

Answer 21

Some fungi are single celled whilst others have a body that is made up of thread like structures called hyphae.

These can grow and penetrate human skin and the surface of plants and cause disease. They produce spores spreading the disease

Question 22

What are hyphae?

Answer 22

Thread like structures that make up the fungi body

Question 23

How are communicable disease transmitted? (7)

Answer 23

Air, water, surfaces (touch), body fluid, animal vectors, soil, food.

Question 24

How are communicable spread by water?

Answer 24

Drinking or bathing in dirty water

Cholera causes diarrhoea and dehydration.
Spread from the diarrhoea from other suffers.

Question 25

How are communicable disease spread through the air?

Answer 25

Droplets produced when you cough or sneeze others breath in.
E.g flu/influenza

In plants it can be transmitted through the wind.
E.g. Chalara ash dieback

Question 26

How are communicable disease spread on surfaces?

Answer 26

Som pathogens can be picked up by touching contaminated surfaces.

E.g. TMV (Tobacco Mosaic Virus) make the leaves of tomato plants mottled and discoloured effecting photosynthesis effecting the growth. Spread through infected leaves rubbing against healthy leaves

Athletes foot. Fungal disease which makes the skin on feet itch and flake off. Passed through touching the same surfaces as an infected person.

Question 27

How are communicable disease spread through body fluids? 3

Answer 27

Blood: sharing needles, contaminated blood transfusion
Breast milk
Semen: unprotected sex (STD/STI) e.g. HIV
HIV initial flu like symptoms then no symptoms for several years
Enters the lymph system and attacks the immune cell (AIDS)

Question 28

How are communicable diseases spread by animal vectors?

Answer 28

Animals vectors are animals that spread disease e.g. a mosquito with malaria. Caused by a protist. Part of the life cycle of the protist takes place inside the mosquito.

The mosquito picks up the protist when feeding on an infected animal then passes it on by inserting the protist in to the animals blood vessel when feeding

Malaria causes repeating episodes of fever and can be fatal

Question 29

How are communicable disease transmitted in soil?

Answer 29

Some pathogen can live in soil so plants that live in the soil can get infected.

Bacteria that causes crown gall disease are able to live freely in soil and the roots of some plants. If the plant get’s infected it can get growths or tumours called galls

The galls can damage plant tissue, restricting the flow of water. The plant becomes weaker and may die

Question 30

How are communicable disease transmitted through food?

Answer 30

By eating contaminated food.

Salmonella is an example of this. If the food isn’t cooked properly or kept too long then Bactria can infect it.