Download Holyrood Secondary School Higher Human Biology Unit 4

Holyrood Secondary School
Higher Human Biology
Unit 4
Immunology and Public Health
Homework 1-8
Homework 1 – Non-specific defences
1. The diagram below illustrates the fluid mosaic model of a plasma membrane.
Substance Z is an antigen.
(i) What is an antigen?
(ii) Explain the difference between self and non-self antigens.
2. Which of the following is a cell which engulfs bacteria?
A
B – lymphocyte
B
T – lymphocyte
C
Lysosome
D
Phagocyte
3. Which of the following types of white blood cell is involved in a non-specific immune
response which causes apoptosis in invading pathogens?
A
Phagocytes
B
B lymphocytes
C
T lymphocytes
D
Natural killer cells
4. The flow chart below outlines some non-specific defence responses which occur when
tissue is damaged and invaded by bacteria.
(a)
Describe how histamine changes the arteries and capillaries to bring about the effects
shown in the flow chart.
(b)
Describe the role of cytokines in the inflammatory response.
(c)
Describe the role of natural killer (NK) cells in apoptosis.
5. Describe non-specific defences that the body uses to protect itself from pathogens.
Homework 2 – Specific cellular defences
1. Lymphocytes act in the defence of the body by
A
ingesting toxins
B
ingesting pathogens
C
producing lysosomes
D
producing antibodies
2. Which of the following is an immune response
A
T-lymphocytes secreting antigens
B
T-lymphocytes carrying out phagocytosis
C
B-lymphocytes combining with foreign antigens
D
B-lymphocytes producing antibodies
3. The diagram below represents the body’s response to BCG vaccination against
tuberculosis.
(a) (i) Where does B – cell activation occur?
(ii) What feature of the injected bacteria activates the B – cells?
(b) Name the protein molecule Y secreted by the plasma membrane and state its
function.
Protein Y –
Function –
(c) What is the function of memory B – cells in the immune response?
(d) Why do the bacteria present in the vaccine not cause tuberculosis?
(e) How does passive immunity differ from BCG immunisation?
4. The diagram below represents an immune response following a viral invasion.
(a)
(i) Name the defence cells which are mobilised during this response.
(ii) What feature of the invading virus is recognised by the defence cells?
(iii) Name the cell secretions which destroy viruses.
(b)
If the same virus invades the body again, a secondary immune response occurs.
How does this response differ from the primary response?
5. The diagram below shows a section through a lymph node.
(a) Complete the table below to naming the cells, and describing their functions.
(b)
Add an arrow to the diagram to indicate the direction of flow of lymph in vessel X.
Give a reason for your choice.
Reason –
(c) Describe one way in which the composition of lymph differs from plasma.
(d) What eventually happens to the lymph after it leaves the gland?
(e) Describe one function of the lymphatic system, apart from protecting the body from
infection.
6. The diagram below shows three stages in an immune response.
(a) (i) What type of white blood cell carries out the immune response shown?
(ii) What name is given to foreign molecules which stimulate the immune response?
(b)
Describe two responses made by the white blood cell as a result of the attachment
of the foreign molecules.
(c)
A person was injected with a vaccine on day 1 and again on day 36 of a 70 day
clinical trial. The table below shows the concentration of antibodies to this vaccine
in this person’s blood at the end of each 7 day period during the trial.
(i) How many times greater was the maximum antibody concentration following the second
injection compared with the maximum concentration following the first?
Space for calculation
times
(ii) The second injection caused a higher concentration of antibody to be produced than
the first injection.
Identify two other differences in the response to the second injection.
(iii) State two improvements that would need to be made to this trial to ensure that the
findings were statistically significant.
7. The diagram below shows a polio virus.
(a) This virus can be used to prepare a polio vaccine. In order to do this, the nucleic acid
must be broken up, but the surface proteins must be left intact.
Explain why it is necessary to:
(i)
break up the nucleic acid
(ii)
leave the surface proteins intact
(b) The average diameter of a red blood cell is 7 µm.
By how many times is a red blood cell bigger than a polio virus? (1µm = 1000m)
Space for calculation
Times
8. The diagram below shows blood from a person who has been infected by bacteria.
These bacteria have triggered an immune response involving proteins P and Q.
Phagocyte
(a) (i) Identify proteins P and Q.
P
Q
(ii) Cell R produced protein Q.
Name this type of cell.
(iii) Describe the role of the following cells in combating infection.
Phagocyte
(b) Describe what happens during an autoimmune response.
Homework 3 – Transmission and Control of Infectious Diseases
1.
The graph below shows the number of cases of meningitis and deaths due to meningitis in
the UK from 1998 to 2001.
In which year was the number of deaths from meningitis less than 10% of the number
of cases?
A
1998
B
1999
C
2000
D
2001
2. When a disease occurs regularly in an area it is classified as being
A
sporadic
B
pandemic
C
epidemic
D
endemic
3. The table below contains information about the number of cases of influenza in
Dundee over a five year period.
Which of the following conclusions can be drawn from the data in the table?
A
There are always more cases of influenza in January than in July.
B
The number of cases of influenza decreased by 75% between January and July
of 2005.
C
The greatest percentage decrease in influenza cases occurred between January
and July of 2003.
D
The greatest percentage increase in influenza cases occurred between July
2002 and January 2003.
4. Several outbreaks of infectious diseases are described in the table below. Complete
the table by matching the following words classifying the spread of infectious
diseases to the correct description.
Epidemic
Pandemic
Endemic
Sporadic
Description
An outbreak of chicken pox in the UK
The outbreak of ‘whooping cough’ in Shetland in 2013
The outbreak of Ebola in Western Africa in 2014
The global spread of HIV
Spread of Infection
5. Give an account of infectious diseases under the following headings:
(i)
the classification of the spread of diseases;
(3)
(ii)
the transmission of disease;
(3)
(iii)
the control of disease.
(4)
Homework 4 – Immunisation, Vaccination and Evasion of Immune Responses
1. Adjuvants are often added to vaccines to
A
make the vaccine safer
B
enhance the immune response
C
make immunity last for a longer time
D
ensure the vaccine contains no live pathogen
2. In a clinical trial of a vaccine, researchers placed volunteers into two groups.
Each group contained individuals of matched ages.
The researchers then gave group A an injection of the vaccine and group B an injection of
a dilute sugar solution.
Which of the following protocols was used in this trial?
A
Placebo controls
B
Pedigree analysis
C
Double blind design
D
Randomised allocation
3. On which of the following does the herd immunity threshold not depend?
A
Type of disease
B
Population density
C
Effectiveness of the vaccine
D
Quarantine of non-immune individuals
4. Concerns about the MMR vaccine caused the percentage of children in the UK immunised
against measles, mumps and rubella to fall below the critical level of 80% between 2000
and 2005. As a result, outbreaks of these viral diseases occurred in various parts of the
country.
(a) (i) State what is present in an injection of vaccine.
(ii) Explain how the process of vaccination prevents a child from showing symptoms of
mumps during future outbreaks of the disease.
(iii) Suggest why these diseases spread more rapidly when the vaccination level falls
below 80%.
(b)
Unlike the MMR vaccine, a different vaccine is required against each strain of the
influenza virus.
(i)
Suggest why different vaccines are required
(ii)
Give the reason why a vaccine for influenza should be given annually.
(c)
Researchers are attempting to develop a new vaccine which will be effective against
all strains of the influenza virus. Trials of this new vaccine have shown that it
increases the activity of T-lymphocytes in the body.
Describe two ways in which T-lymphocytes combat infection.
(d)
Clinical trials of vaccines use several different design protocols. Describe how the
correct protocols would be set up for:
1.
A randomised, placebo-controlled trial.
2. A double-blind trial.
5.
Describe the importance of herd immunity in the control of infectious disease.
Homework 5 – The Inflammatory Response
Give an account of the inflammatory response. (8 marks)
Homework 6 – Clonal Selection Theory
Give an account of clonal selection theory. (6 marks)
Homework 7 – Controlling the Spread of Pathogens
Describe the role of community responsibility in the control of the spread of
pathogens. (6 marks)
Homework 8 – Public Health Immunisation Programmes
State the aim of public health immunisation programmes and explain why they
may fail to protect non-immunised individuals. (6 marks)