Communicable disease

Question 1

what is health?

Answer 1

a state of complete physical, mental and social well-being.

Question 2

define communicable and non communicable diseases:

Answer 2

communicable = can be transferred from one person to another
non-communicable = cannot be transferred between people or other organisms

Question 3

what do defects in the immune system result in?

Answer 3

an individual is more likely to suffer from infectious diseases.

Question 4

what does HIV do and how does it affect an individual?

Answer 4

affect the immune system and leads to an increase in susceptibility to infectious diseases.

Question 5

what happens if viruses live in cells?

Answer 5

they can be the trigger for cancers

Question 6

what does the reaction of the immune system to foreign bodies result in sometimes?

Answer 6

allergic reactions

Question 7

what could be classified as a pathogen?

Answer 7

viruses, bacteria, fungi and protists

Question 8

what is cholera caused by?
what are its symptoms?
how is it spread?

Answer 8

bacteria
diarrhoea, vomiting & stomach cramps
water

Question 9

what is tuberculosis caused by? what does it lead to?
what are its symptoms?
how is it spread?

Answer 9

bacteria that leads to lung damage
coughing up blood, high temperature, tiredness and fatigue
airborne

Question 10

what is clara ash dieback caused by?
what are its symptoms?
how is it spread?

Answer 10

fungi
causes leaf loss and bark lesions
airborne

Question 11

what is malaria caused by?
what are its symptoms?
how is it spread?

Answer 11

protists
damage to blood and liver
animal vectors

Question 12

what is HIV caused by?
what are its symptoms?
how is it spread?

Answer 12

virus which destroys white blood cells, leading to onset of AIDS
mild flu-like symptoms
bodily fluids, sharing needles

Question 13

what is helicobacter caused by?
what are its symptoms?
how is it spread?

Answer 13

bacteria
indigestion, stomach ulcers
oral transmission (saliva)

Question 14

what is Ebola caused by?
what are its symptoms?
how is it spread?

Answer 14

virus
diarrhoea, vomiting, stomach pain and internal bleeding. + haemorrhagic fever
bodily fluids

Question 15

describe (simply) the life cycle of a pathogen: (3)
+ if its a virus

Answer 15

they infect a host
reproduce themselves or replicate

if it is a virus, spread from their host and infect other organisms

Question 16

describe the 3 main categories of non-communicable diseases:

Answer 16

-Inherited genetic disorders like cystic fibrosis can be passed to offspring but not to anyone else.

-Deficiency diseases which are caused by a lack of essential vitamins or minerals, such as scurvy which occurs when an individual has insufficient vitamin C.

-Diseases like cancer that develop as a result of exposure to carcinogens or develop naturally as cell division occurs incorrectly.

Question 17

what are the 5 types of disease transmission?

Answer 17

direct contact, water, air, unhygienic food preparation. vector

Question 18

describe ‘direct contact’ and ‘water’ as methods of transmission:

Answer 18

Direct contact = This can be sexual contact during intercourse or non-sexual contact, like shaking hands.

Water = Dirty water can transmit many diseases and harbour bacteria

Question 19

describe ‘air’ and ‘Unhygienic food preparation ‘ as methods of transmission:

Answer 19

When a person who is infected by the common cold sneezes, they can spray thousands of tiny droplets containing virus particles to infect others.

Undercooked or reheated food can cause bacterial diseases like Escherichia coli which is a cause of food poisoning.

Question 20

describe a ‘vector’ as a mode of transmission:

Answer 20

Any organism that can spread a disease is called a vector. Many farmers think tuberculosis in their cattle can be spread by badgers.

Question 21

how do viruses reproduce?

Answer 21

They do not divide and reproduce like cells, but complete the lytic pathway.

Question 22

describe the lytic pathway: (4)

Answer 22

• they replicate their DNA and protein coats.
• these are then assembled into new virus particles.
• host cell or cells to burst. this is called lysis
  -Other nearby cells can then be infected with the virus.

Question 23

what happens in the lysogenic pathway? (3)

Answer 23

• viruses join their DNA to that of their host or leave small circles of their DNA in the cytoplasm of their host cell or cells.
• when these cells divide the DNA is copied.
• later in the life cycle the viral DNA is copied and the lytic cycle detailed above begins.

Question 24

how do we refer to viruses since they are not a specie (an organism)?

and define the meaning of this:

Answer 24

strains

relatively short length of genetic material (DNA) which is surrounded by a protein coat.

Question 25

how does HIV become AIDS

Answer 25

after months (or years) of acquiring HIV, virus becomes active and attacks the patient’s white blood cells.

Question 26

what is the treatment for HIV/ AIDS?

Answer 26

antiviral drugs, which can significantly slow the development of AIDS.

Question 27

what do the symptoms of cholera cause people to go into?

Answer 27

Having diarrhoea and vomiting mean infected people quickly become dehydrated and can go into shock

Question 28

what could help prevent cholera + treatments:

Answer 28

-a vaccine is available and antibiotics are used
-oral rehydration solutions (which contain salts and glucose to substitute the lost ones) to prevent dehydration and shock.

Question 29

what is used to treat tuberculosis? + treatments:

Answer 29

BCG vaccine prevents infection with TB. If infected, antibiotics are prescribed.

Question 30

what does the helicobacter do?

Answer 30

starts to irritate the lining of the stomach which then stops protecting them from the hydrochloric acid in their stomach, which forms an ulcer