Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology A-Level > Immunology > Flashcards

Immunology Flashcards

1
Q

what are the 2 types of immune response

A

non specific and specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what can trigger an immune response

A

pathogens
cells from other organisms
abnormal/cancerous/tumour cells
cells infected by a virus
injected antigens
our own cells if autoimmune disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe the non specific immune response

A

-the phagocyte binds* to foreign antigen of pathogen and phagocytosis occurs creating a phagosome
-lysosome containing lysosome enzymes fuses with phagosome and hydrolyses pathogen
-breakdown products are absorbed by phagocyte and antigens can be presented on cell membranes
*the phagocyte is attracted to chemicals released by pathogens, dead/ abnormal animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does a specific response lead to?

A

immunity-long term response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the 2 types of specific response?

A

-cellular response
-humorous response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a cellular response?

A

cell mediated immunity-for use on foreign cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is a humoral response

A

humoral immunity- for use on non cellular foreign bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of lymphocytes are cellular responses carried out by?

A

T-lymphocytes(made in the thymus glands)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the types of T lymphocytes that are involved?

A

-helper T lymphocyte
-cytoxic T lymphocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the possible targets of cellular responses?

A

-foreign(transplanted) cells
-virus infected cells
-cancer cells
-phagocytes that are presenting foreign antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe a cellular response

A

1.Helper T lymphocytes with complementary receptor binds to foreign antigen
2.helper T lymphocyte is activated and undergoes mitosis
3.Activated helper T lymphocyte will then -activate more phagocytes
-activate cytotoxic T lymphocyte
-activate B lymphocytes
-become memory T lymphocytes which do the above(1 and 2) upon reinfection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What lymphocytes are humoral responses carried out by?

A

B lymphocytes (made in the bone marrow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe a humoral response

A

1.a specific B lymphocyte with a complementary receptor takes in pathogen via endocytosis
2.B lymphocyte presents foreign antigen on cell membrane
3.helper T lymphocyte will bind to presented antigen and trigger mitosis
4.Some B cells plasma cells and secrete antibodies
5.Some become B cells become memory cells which persist and rapidly divide into plasma cells upon reinfection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is agglutination useful in a humoral response?

A

antibodies cause agglutination, which is the ‘clumping of pathogens’, which makes it easier for pathogens to find.
marks for destruction by phagocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do memonry T cells do?

A

Remember the specific antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What do memory B cells do?

A

Remember the antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe and explain the shape of curve A primary response

A

-Antigen enters body for the FIRST time.
•The response is SLOW, due to there are very few B-CELLS that can make the antibody needed.
•Person shows symptoms in the time for the antibodies to be made.
•After exposure, both T-CELLS & B-CELLS produce “memory cells” which remain in the body.
•The person is know said to be “Immune”, which means their immune system has the ability to responds very quickly if the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe and explain the shape of curve A secondary response

A

When the same antigen enters the body again, the immune system gives a “quicker, stronger” immune response.
This is down to the “memory cells” and the fact Clonal Selection can occur much faster.
Memory T-Cells are activated and divide into the correct T-Cells to kill the cell carrying the antigen.
Memory B-Cells are activated and divide into plasma cells that produce the right antibody for the antigen.
The Secondary Response will often kill the pathogen before any symptoms show.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why do diseases like the cold and flu occur in many forms?

A

Why do diseases like the cold and flu occur in many forms?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do viruses like flu evade the immune system?

A

Viruses can mutate, changing their antigen so the body can’t recognise them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How many groups of influenza virus are there?

A

3
Type A type B and type C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How are influenza vaccines prepared?

A

They are made using a mixture of type A and type B antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What makes flu outbreaks particularly dangerous?

A

The virus mutates frequently, and new strains emerge that the immune system hasn’t encountered before

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why do most people only suffer from the symptoms of diseases such as chicken pox and measles once?

A

It is because there is only 1 type of pathogen causing those diseases. If there is reinfection the memory cells respond, and the pathogen is killed before symptoms develop.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is antigenic variability?

A

Antigenic variability is when the antigens on the surface of a pathogen constantly change making it difficult for the immune system to recognise and respond to the pathogen

26
Q

Why can people catch the flu multiple times?

A

The influenza virus has over 100 strains, and its antigens frequently change due to antigenic variability. Memory cells from a previous infection will no longer be complimentary.

27
Q

What happens during reinfection with a pathogen that has already undergone antibiotics antigenic variability?

A

A primary immune response must occur (as if it has never encountered the pathogen before). This takes a while and tge symptoms are suffered all over again (headache, sore throat, high temperatures etc)

28
Q

How does antigenic variability challenge vaccine development?

A

Vaccines must be regularly updated to include antigens from the most common strains of pathogens like influenza due to constant antigen changes

29
Q

What is immunity.?

A

The ability to resist infection

30
Q

What are the 2 types of immunity ?

A

Active and passive

31
Q

What is active immunity?

A

Antibody stimulation occurs in an organism and the immunity is usually long lasting.

32
Q

What is passive immunity?

A

Antibodies are introduced by an outside source. This is usually short lived immunity as the introduced antibodies are broken down and not replaced by the bodies white blood cells.

33
Q

Give an example of active immunity

A

you get from naturally catching a disease(naturally acquired), or from being vaccinated with a harmless dose of an antigen(artificially acquired)

34
Q

Give a example of passive immunity

A

you get from mum through the placenta and breast milk (naturally acquired)or when you are injected with antibodies from someone else.(artificially acquired)

35
Q

What are the differences between active immunity and passive immunity?

A

•Active immunity requires exposure to antigen whilst passive immunity doesn’t require exposure to the antigen.
•active immunity takes time for the protection to develop whilst for passive immunity protection is immediate.
•active immunity memory cells are produced whilst for passive immunity they aren’t
•active immunity protection is long term whilst for passive immunity protection is short term

36
Q

How do we achieve immunity ?

A

By vaccination. A vaccine introduces a substance into the body which stimulates the immune response to a specific disease. When vaccination programmes are carried out on a large scale this can lead to short term immunity in a whole population.

37
Q

What is an attenuated vaccine?

A

An attenuated vaccine is a vaccine created by reducing the virulence of a pathogen, but still keeping it viable (or “live”). Attenuation takes an infectious agent and alters it so that it becomes harmless or less virulent

38
Q

What is needed for a successful vaccination programme?

A

There must be sufficient quantities of the vaccine to immunise a large population.
-There must be no / few side-affects as this discourages people from getting it.
-There must be a way of producing, transporting and organising the vaccine.
-There must be an efficient way to administer the vaccine in large populations.
-It must be possible to vaccinate all or most of the population, this is herd immunity.

39
Q

Why do vaccination programmes not always eliminate disease?

A

Some individuals have a defective immune system to immunity is not achieved through vaccination.
•If the disease is caught soon after vaccination the immune system may not have already built up resistance. The disease can then be passed on.
•If the pathogen mutates frequently (antigens change) vaccines become ineffective because the vaccination may only be against one strain of a disease which has over 100 strains (e.g. the common cold).
•Some pathogens hide in body cells, or body parts concealed from the immune system (intestines).
•Individuals may refuse the vaccination for medical, ethical, religious or ‘daft’ reasons.

40
Q

What are the difficulties with the cholera vaccine?

A

Cholera hides in the intestines which are hidden from the immune system. If oral treatments is given it is often flushed from the system by diarrhoea (caused by the pathogen) before it has the chance to work.
•The antigens of cholera frequently change (mutate).
•Movement of people from country to country makes it difficult to keep check of who has been / need vaccinating.

41
Q

What are the difficulties with the tuberculosis vaccine

A

•A rise in HIV cases has led to a rise in TB cases as those with suppressed immune systems (HIV sufferers) are more likely to catch TB.
•Poverty due to various reasons leads to lots of people living closely in unsanitary conditions which aids the spread of TB.
•Movement of people from country to country makes it difficult to keep check of who has been / need vaccinating.
•The number of elderly people in populations are increasing. They have weaker immune systems so vaccination is less likely to work.

42
Q

What are the types of vaccine ?

A

•Killed pathogens
•Isolated antigens
•Genetically engineered antigens
•Attenuated strains (non-virulent form)
•Toxoids (modified toxins)

43
Q

What are some ethical issues of vaccines?

A

•all vaccines are tested on animals before being used on humans
•testing vaccines on humans can be tricky
•some people do not want to take the risks of side effects of using vaccines

44
Q

What is an ethical issue of monoclonal antibody therapy?

A

Animals are used to produce the cells from which monoclonal antibodies are produced.

45
Q

What is herd immunity?

A

If you vaccine a large portion of a population, then there will be less chance of those not vaccinated catching the disease.

46
Q

What stimulates an immune response and how?

A

Antigen- stimulates the production of an antibody eg.toxin, bacteria etc

47
Q

What are antibodies?

A

Antibodies are proteins synthesised by B - cells when the body is invaded by a non-self or foreign material.
•Each antibody is specific to its own complementary antigen.
•There are a huge number of antibodies.

48
Q

Describe and explain the antibody structure.

A

Antibodies are made of 4 polypeptide chains (quaternary protein structure).
•There are:
-2 long HEAVY CHAINS and 2 short LIGHT CHAINS
Their shape can alter to aid attachment to the antigen. They are Y-shaped and have a binding site which fits into the complementary antigen to form a ANTIGEN-ANTIBODEY COMPLEX.
The binding site differs for every antibody so it is called the VARIABLE REGION.
Each site is made of a sequence of amino acids which forms a 3D shape and fits a specific antigen.
The rest of the structure is the same for each antibody and is called the CONSTANT REGION. This binds receptors on cells like B-cells.

49
Q

What is agglutination?

A

Pathogens clumped together

50
Q

Why can antibodies bind to two pathogens at the same time?

A

Because it has 2 binding sites

51
Q

What are polyclonal antibodies?

A

Each of the different proteins on the surface of a pathogen will induce a different B-cell to clone itself.
•Each different clone of each different B-cell will produce a different antibody.

52
Q

What are monoclonal antibodies?

A

•A single type of anybody for a specific pathogen that can be cloned

53
Q

How do you produce monoclonal antibodies?

A

Inject mouse with chosen antigen and grow fast dividing tumour cells in the lab. Take b-lymphocytes from the mouse and fuse it with tumour cell. This makes hybridoma. It divides quickly to produce lots of clones that produce the monoclonal antibodies

54
Q

What can monoclonal antibodies be used for?

A

-Pregnancy tests
-They can be used to diagnose hepatitis, HIV, herpes and chlamydia infections. (detecting pathogens)
-they can carry toxic drugs or radiation to cancerous cells. An example of this type of drug is Herceptin.

55
Q

What is the problem with using mouse derived (murine) mAbs in humans

A

They may be recognised as foreign. This will trigger an immune response which quickly inactivates the mAbs

56
Q

How can the immune response be minimised when using mAbs?

A

The immune response can be minimized by using genetic engineering to create humanized mAbs. These consist of mainly human polypeptide chains, with only the amino acids at the antigen-binding site derived from mice.

57
Q

What can be detected by binding a fluorescent dye to a complementary antibody?

A

•Measure blood hormone levels.
•Test blood for pathogens.
•Locate specific molecules on a cell or tissue.
•Diagnose blood clots.

58
Q

How can monoclonal antibodies lead to medical diagnosis?

A

Affected individuals often produce a specific protein/antigen usually present in the blood. Monoclonal antibodies can detect the presence of this antigen and also determine how much is present. If they are unaffected monoclonal antibodies would bind to nothing and this would give a negative result.

59
Q

How can monoclonal antibodies diagnose prostate cancer?

A

Prostate cancer results in more PSA (prostate specific antigen) production. Using monoclonal antibodies can give a measurable level or PSA present in blood. This does not conclude that the disease in present, but is a good early warning

60
Q

How do we treat cancer?

A

-Cancer cells have antigens that are not found on normal cells. We call them tumour markers
-As antigens are specific, monoclonal antibodies can be made that will bind only to tumour cells.
-anti cancer drugs can be attached to these antibodies
-When the antibodies come into contact with the cancer cells, they bind to the tumour markers.
-The anti-cancer drug will also accumulate at the area of the cancer cells, as they are taken along to the correct area with the antibodies. This means that any side effects are lower as they accumulate in one place only rather than being distributed all over the body, such as other chemotherapy drugs do.

61
Q

How are monoclonal antibodies linked to pregnancy testing?

A

Pregnant woman produce a high level of a protein known as hCG in their urine. Monoclonal antibodies linked with a coloured particle present on a pregnancy test strip bind to this antigen (if present) and move along the strip to the test window where a positive result would be seen.

62
Q

Explain how a pregnancy test works [6mark]

A

1.Urine passes through reaction zone.
2.HCG hormone binds to the mobile HCG antibody.
3.Passes up the stick and HCG hormone binds to the immobilised HCG antibodies in the results zone
4.Antibodies which do not attach to HCG
5.Bind to antibodies in control zone
6.Blue dye appears in both control and results zones (to show positive result)

Biology A-Level (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions