Quiz 31 Flashcards
Why are antibodies described as specific?
Antibodies can only bind to one type of antigen
How do antibodies help clump pathogens together?
One antibody attaches antigens on many pathogens at once which clumps them all together
What are antigens?
Small marker proteins on the surface of cells(including pathogens)
How does the stomach prevent pathogens entering the body?
Contains hydrochloric acid which kills any pathogens which are eaten(or trapped in swallowed mucus)
What are cilia?
Cilia are hair-like structures on the surface of some cells
Describe the ways the human body prevents pathogens from entering, and defends itself against pathogens inside the body(6 marks)
Skin provides a barrier to prevent entry. If pathogen enters through a nose, they are trapped by small hairs. Pathogens can also be trapped by sticky mucus produced by the trachea and bronchi. The mucus is swept up the trachea by cilia on ciliates epithelial cells. It is then swallowed mucus, or food, are killed by stomach acid in the stomach. If pathogens do enter the body, the immune system defends the body. It produces white blood cells which engulf pathogens(phagocytosis) produce antitoxins to neutralise toxins, and produce antibodies. Antibodies clump pathogens meaning they are more easily killed by phagocytosis
List 3 ways memory cells cause a stronger immune response following reinfection, or infection after a vaccine
Antibodies made sooner, antibodies made faster, overall more antibodies are made
How do vaccines work(6 marks)
- Dead/inactive pathogen injected 2. This causes white blood cells to produce antibodies. 3. Some white blood cells form memory cells.
4.if pathogen reinfects later, memory cells recognise pathogen. 5. This causes many antibodies to be made very fast, very soon after infection 6. Pathogen killed before their population is large enough to cause disease
