Helper T cells recognize antigens displayed on macrophages and activate other immune cells including B cells and T cells. Activated B cells produce antibodies that destroy pathogens, while activated T cells destroy pathogen-infected cells. Memory cells remain after an infection to provide faster protection if the same pathogen is encountered again. Vaccines provide active artificial immunity by exposing the immune system to an inactivated or weakened form of a pathogen. They work by generating memory cells and antibodies that can quickly respond to a real infection.

1. Unit:3- Human immune system
Qatar Independent
Secondary School Support -1 (STANDARDS: 11.1,11.2)
1.What is the role of Helper T cell in immune response?
A ________________ ingests foreign antigens and displays antigen fragments on its surface.
Helper T cell (TH) ____________________________________________________________________ and
____________________________ - B cells, as well as T cells .Bcells make _________________ which
produce __________________ and destroy pathogen. T cells make _____________ which destroy
____________________________________________________ directly.
2. Name and state the function of cell A and B shown in the diagram below ?
A.______________________________
_________________________________
_________________________________ A
B.__________________________________
B
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3.How does B Cell and T cell differ in their function to protect us from diseaes?
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2. 3.How does B Cell and T cell function in similar way to protect us from diseaes?
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4. What are the function of different types of T cells?
5. Explain the function of Memory cell?
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____________________________________________
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3. Unit:3- Human immune system
Qatar Independent
Secondary School Support -3 (STANDARDS: 11.3)
1. Label the structure of antibody
2. How are antibody molecules adapted to their function? B C Antigen
A
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3. How does antibody antigen complex defend your body?

4. Unit:3- Human immune system
Qatar Independent
Secondary School Support -4 (STANDARDS: 11.5)
1.Some people are allergic to pollen. List the steps the immune system goes
through when these people are exposed to pollen?
12,3_______________________________________________________
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4,5______________________________________________________
._________________________________________________________
2.Label mast cell,histamine and dilated blood vessel.What is the role of histamine in
allergy response? How do antihistamines help reduce an allergic attack?
________________________
________________________
________________________
________________________
3. Give 2 symptoms of allergy?
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5. Qatar Independent Unit:3- Human immune system
Secondary School
Support -5 (STANDARDS: 11.6)
1.Classify the correct type of immunity? Put( + )Mark
Antibody Vaccine
A B D
C
Active Passive
A
B
C
D
2- How are vaccines effective in preventing disease?Why do you develop disease even after
getting vaccine?
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3-Differentiate between Active natural immunity and Passive natural immunity?
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4. A vaccine may contain _____.
a. white blood cells that fight infection b. antibodies that recognize invading microbes
c. inactivated disease-causing microbes d. a hormone that boosts immunity
5. Explain why the respone to the secondary infection is much greater than the responsse to
the primary infection?
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