2025-2026
Different locations of the human body use different resistance strategies to help protect the
human host from microbial invaders. Match each strategy with the correct location in the
human host. - Answers Respiratory tract - Mucociliary system.
Gastrointestinal tract - Peristalsis.
Skin- Sodium Chloride.
Genitourinary tract - presence of uric acid, fatty acid and mucins
An ___________ presenting cell, such as a macrophage, dendritic cell, or B cell, takes in the
antigen or pathogen by receptor-mediated endocytosis or phagocytosis and produces antigen
fragments by digestion in the phagolysosome. - Answers Antigen
Leukocytes, or white blood cells, are the cells responsible for the innate defenses. Match the
different leukocytes with a key characteristic. - Answers Vasoactive mediator - mast cell
Important in defense against protozoa and helminths parasites - eosinophil
A granulocyte that contains histamine - basophill
Principal phagocyte responder in blood - neutrophils
Mature into macrophages - monocytes
Present antigens to lymphocyte - dendritic cell
The largest phagocytic cell in body - macrophages
An antigen is best described as __________. - Answers A defense molecule that eliminates
foreign substances
Which of the following statements is correct about the development of T cells? - Answers T
cells differentiate into progenitor cells destined to become (1) natural T regulatory (Treg) cells,
, (2) natural killer T (NKT) cells, (3) gamma/delta T cells, and (4) alpha/beta T cells.
A person lacking Paneth cells would be more likely to get an infection of their ________. -
Answers Gastrointestinal tract
The complement system acts in a cascading fashion to ________. (Check all that apply.) -
Answers - Enhance phagocytosis
- Lyse cell membranes of target cells
- Produce inflammatory peptides
Assess the following statements and classify them according to whether they refer to T-cell
receptors or B-cell receptors. - Answers Tcell receptor:
- Heterodimeric α/β polypeptides
- Cytoplasmic tails interact with cd3 polypeptides
- Six accessory polypeptides
B cell receptor:
- Igα/Igβ heterodimers
- Transmembrane immunoglobin
- Monomeric IgM and IgD.
Which of the following statements is true about clonal selection of lymphocytes? - Answers
Once a lymphocyte has been released from its primary development site and is exposed to its
specific antigen, it proliferates to form a clone (a population of identical cells derived from a
single parent cell).
To date, probiotics have successfully been used in humans, but not animals.
Group starts - Answers False
The acute inflammatory response begins when injured tissue releases chemical signals called
____________ . - Answers Chemokines
These signals stimulate the cells lining the capillaries to display ____________ on their surface,
which attract wandering ____________ . - Answers Selectins; neutrophils
These white blood cells produce ____________ , which allow them to bind to the selectin-positive
epithelial cells in a process called ____________ . - Answers Intregens; margination