Download Human Defence System

The Human Defence System
Section A – Higher Level
2006 HL
6.
Distinguish between the members of each of the following pairs by making a brief comment
on each.
(a)
Tuber and bulb
(b)
Ureter and urethra
(c)
Hypha and mycelium
(g)
Thigmotropism and chemotropism
(e)
Antigen and antibody
2010 HL
6.
(c)
During 2009 swine flu spread through the population of many countries.
Younger people were more at risk of becoming ill with swine flu than older
people. Using your knowledge of the immune system, suggest a reason for
this.
Section C – Higher Level
SEC Sample Paper HL
15.
Answer any two of (a), (b), (c).
(30,30)
(b)
(i)
(ii)
(iii)
(iv)
What is meant by the term immunity? Distinguish between active and passive
immunity.
Describe two ways in which the skin helps to defend the body against pathogenic
micro-organisms.
Lymphocytes play a vital role in the body's immune system. To which group of
blood cells do lymphocytes belong? Name two types of lymphocyte and state a
role of each.
What is the purpose of vaccination?
2005 HL
15.
Answer any two of (a), (b), (c).
(30,30)
(a)
(i)
(ii)
(iii)
(iv)
Comment briefly on the difficulty in classifying viruses as living organisms.
Name two diseases of humans caused by viruses.
Name two types of lymphocyte and state a role of each when viruses or other
micro-organisms enter the blood.
“Immunity that results from vaccination is effectively the same as the immunity
that develops following an infection". Do you agree with this statement?
Explain your answer.
2007 HL
14.
30)
Answer any two of (a), (b) and (c).
(c)
(i)
(ii)
(iii)
(iv)
(v)
(30,
What is meant by the term immunity?
Outline briefly the role of B lymphocytes in the human immune system.
Distinguish between active and passive immunity.
“Vaccination gives rise to active immunity”. Explain this statement.
In certain situations a person is given a specific antibody rather than being
vaccinated.
1.
Is this an example of active or passive immunity?
2.
Under what circumstances might an antibody, rather than a vaccination,
be given?
3.
Comment on the duration of immunity that follows the administration
of an antibody.
20120 HL
15. Answer any two of (a), (b), (c).
(b)
(i)
(ii)
(iii)
1.
2.
3.
State two ways, other than colour, in which red blood cells differ from white blood cells.
Name a group of white blood cells, other than lymphocytes.
Lymphocytes may be divided into B cells and T cells. B cells produce antibodies.
What is the role of antibodies in the body?
Name any three types of T cell.
State a role of each of the T cell types that you named in part 2.
Section C – Ordinary Level
2011 OL
15.
Answer any two of (a), (b0, (c)
(30,30)
(c)
The diagram shows the structure of a type of virus.
(i)
(ii)
(iii)
(iv)
Name the parts labelled A and B.
State two harmful effects of viruses.
What is meant by the term immunity?
The skin is an important part of our immune system.
Outline two ways in which the skin provides immunity.
To help the immune system, many people receive vaccinations during their lifetime.
(v)
(vi)
What is meant by the term vaccination?
Antibiotics are usually not given to a person suffering from a viral infection.
Suggest a reason for this.