Pathogens Test

Question 1 - Before an influenza infection can occur, identify one appropriate barrier that would prevent entry of this pathogen into a person.

Mucus

Question 2 - a) Identify the structure that a phagocyte would bind to, to determine if the cell was infected or not.

MHC 1 on an infected cell

Question 2 - b) Identify a mechanism to prevent viral pathogenic infection and describe how it would work.

A vaccine introduces harmless virus antigens, causing the immune system to make specific antibodies and memory cells, so the real virus can be destroyed much faster if it enters the body later.

Question 2 - c) Suggest one treatment an infected person could receive to cure this infection.

Antiviral medication

Question 3) - a) Cells in the cell-mediated (T) cell immune response differentiate into two specific cells. Name each of these cells and explain the function of each.

Memory T cells remember the specific antigen of a pathogen. If the same pathogen enters the body again, they help produce a faster and stronger immune response.

Question 3) - b) Cells in the cell-mediated (T) cell immune response differentiate into two specific cells. Name each of these cells and explain the function of each.

Helper T cells activate and coordinate other immune cells, helping the body fight the infection.

Question 4) - Antibodies play an important role in the adaptive immune response. Draw a clearly labelled diagram of an antibody binding to influenza.

done

Question 5) - In this case, B Cell Humoral immunity has been activated. Outline the role of this process in the adaptive immune response.

After the APC presents the antigen, it activates helper T cells, which activate the specific B cells. The B cells multiply and form plasma cells, which produce antibodies specific to the influenza virus. The antibodies bind to the virus, helping prevent it from infecting cells and allowing it to be destroyed Some B cells become memory cells, providing a faster response if the same virus enters the body again.

Question 6) - a) A woman gets influenza from the air — circle whether this is natural/artificial and passive/active.

natural active

Question 6) - b) Describe what would happen if she caught influenza for a second time.

The second exposure produces a faster and stronger secondary immune response because memory B cells and memory T cells were produced during the first infection.

Question 6 - c) Draw and label a graph showing antibody levels for a primary vs secondary exposure to an antigen, including the lag period.

done

Question 7 - a) Identify the chemical released by mast cells during an allergic/inflammatory response.

Histamine

Question 7 - a) Outline the process of the histamine reaction during inflammation.

• Mast cells detect tissue damage or infected

• They release histamine.

• Histamine causes nearby blood vessels to dilate (widen) and become more permeable.

• This allows more fluid and white blood cells to leave the blood vessels and enter the affected tissue.

• This causes redness, heat and swelling and sometimes pain

• White blood cells help destroy pathogens

Allgeric Rection for Pollen

1. Pollen enters the body

2. The immune system identifies allgern as a theat

3. B cells produve antibodies IgE against allegern

4. 4. IgE antibodies attach to mast call

5. Pollen allgern binds to IgE on mast cells

6. Mast cells release histamine