Explore how keratinized skin, shedding, mucus, cilia, lysozyme and acidic gastric juice protect respiratory and digestive surfaces from pathogen entry in IB Biology SL C3.2.2.
According to the cell theory, living organisms are composed of cells.
Explain the role of cells in the defence against infectious disease.
a. cells of skin provide a physical barrier/produce fatty acids/lactic acid/lysozyme which stops entry of microbes OR
mucous membranes produce mucus to trap pathogens
OR
stomach cells produce hydrochloric acid which kills microbes;
b. platelets start the clotting process preventing access of pathogens;
c. (two types of) white blood cells fight infections in the body;
d. phagocytes ingest pathogens (by endocytosis/phagocytosis);
e. gives non-specific immunity to diseases / ingest any type of pathogen;
f. production of antibodies by lymphocytes/B cells;
g. in response to particular pathogens/antigens;
h. gives specific immunity;
i. lymphocyte/B cell makes only one type of antibody;
j. plasma cells produce large quantity of (one type of) antibody;
k. some lymphocytes act/remain as memory cells;
I. can quickly reproduce to form a clone of plasma cells if a pathogen carrying a specific antigen is re-encountered;
m. results in faster defence against second exposure to specific antigen/pathogen/disease;
7 max