acquiring and controlling immunity - unit 4 AOS 1

Question 1

natural vs artificial immunity

Answer 1

• Natural immunity is immunity that has been developed without medical intervention
• Artificial immunity is immunity to a disease developed by medical intervention.

Question 2

active vs passive immunity

Answer 2

• Active immunity involves the production of antibodies by a person in response to exposure to a particular antigen, an results in the subsequent production of memory cells.
• Passive immunity results from antibodies being obtained from another source and does not result in the production f memory cells.

Question 3

natural active immunity

Answer 3

• Natural active immunity is created when an individual’s own immune system encounters a pathogen and mounts a response against it, creating antibodies and memory cells specific to that pathogen.

Question 4

natural passive immunity

Answer 4

• Natural passive immunity occurs when an individual receives antibodies from a natural source, such as through breastfeeding or via the placenta.

Question 5

artificial active immunity

Answer 5

• Artificial active immunity involves the deliberate and artificial introduction of a disabled pathogen or its toxin to the body. Most commonly, this is done by the injection of a particular vaccine that causes the adaptive immune system to produce antibodies to the introduced antigen

Question 6

artificial passive immunity

Answer 6

• Artificial passive immunity is created when an individual acquires antibodies from an external source via a medical intervention (either via an injection or an infusion). For example, people who have been bitten by a snake are given an antivenom which contains antibodies designed to neutralise the venom.

Question 7

vaccines

Answer 7

• Vaccines are a form of artificial active immunity
• A vaccine is a weakened or attenuated form of the pathogen that contains antigens but is incapable of triggering disease
• The body responds to an injected vaccine by initiating a primary immune response, which results in memory cells being made

Question 8

primary vs secondary immune response

Answer 8

• When a vaccine is first injected into a person, the immune system shows a primary antibody response where only a small number of antibodies is produced. As this is the first time being exposed to the antigen, the response can be delayed.
• A second injection of vaccine produces a secondary antibody response. Often, multiple injections are used to amplify the antibodies and becasue of memory cells throughout the body, the response is much faster.

Question 9

herd immunity

Answer 9

• Herd immunity is achieved when the majority of people in a community are immune to a particular pathogen, helping to prevent the spread of the pathogen to those who haven’t been vaccinated or who haven’t already been infected with the pathogen.
• if a sufficiently large proportion of people in a population are immune to a disease via vaccination, then the pathogen causing that disease cannot easily reproduce and spread through the population.
• This then protects the people who aren’t immune – they are now highly unlikely to come into contact with a person harbouring the pathogen, and therefore won’t become sick

Question 10

properties of pathogens

Answer 10

• how contagious the pathogen is – that is, how easily is it transmitted between people
• how virulent the pathogen is – that is, how severe is the disease the pathogen causes.

Question 11

emerging disease vs re-emerging disease

Answer 11

• an infectious disease that is new to the human population, or that is rapidly increasing in incidence
• re-emerging disease - an infectious disease that was previously under control but that is now increasing in incidence

Question 12

epidemics vs pandemics

Answer 12

• A pandemic refers to the global or very widespread outbreak of a disease.
• An epidemic refers to the occurrence of an infectious disease in a community or in a restricted geographic area at a particular time.

Question 13

conditions that favour the emergence of a disease

Answer 13

• when a new pathogen appears that the people have no immunity to
• when a pathogen can be passed from animals to humans
• increased populations
• increased globalisation and travel
• insufficient vaccination of the population

Question 14

impact of European arrival on the Indigenous population

Answer 14

• British colonisation resulted in the introduction of many new diseases
• a lack of immunity to these diseases meant that the Indigenous population was more susceptible to them
• an increased population densities and a lack of access to clean water and food

Question 15

methods of identifying viruses

Answer 15

physical methods: used to identify pathogens via size and shape
- microscopes
- electron microscopy

immunological: detect specific viral antigens or antibodies
- ELISA

molecular methods: locating specific genetic sequences

Question 16

methods of identifying bacteria

Answer 16

phenotypic: used to identify trains and features

Question 17

modes of transmission

Answer 17

droplet transmission: can remain
suspended in the air for a short period of time, before falling to the ground/onto a surface.

respiratory transmission: particles are spread through the air and inhaled

direct physical contact:

vector transmission:

Question 18

controlling pathogen transmission

Answer 18

• quarantine and isolation
• preventative behaviours such as handwashing, using PPE, using disinfectants
• screening and routine testing
• vaccinations
• medications such as antibiotics and antivirals

Question 19

importance of identifying pathogens

Answer 19

• so we can select appropriate responses to control the spread of disease and provide correct treatment.

how:
microscopes

Question 20

identifying host

Answer 20

• can develop treatments
• can help prevent spread (especially zoonotic diseases)