b1.2 Flashcards
(10 cards)
What is a pathogen and what types are there?
A pathogen is a microorganism that causes disease. Types include bacteria, viruses, fungi, and protozoa.
Describe the body’s first line of defense against pathogens.
Physical barriers like skin, mucus membranes, cilia in the respiratory tract, and stomach acid prevent pathogens from entering or kill them.
What happens during phagocytosis?
White blood cells (phagocytes) engulf and digest invading pathogens.
How do white blood cells produce antibodies?
White blood cells recognize specific antigens on pathogens and produce antibodies that bind to these antigens, marking pathogens for destruction.
What is the role of memory cells in the immune response?
Memory cells remember the specific antigens of pathogens, allowing the immune system to respond faster and stronger if the pathogen invades again.
Explain how vaccination works.
Vaccination introduces a dead or inactive pathogen or its antigens to stimulate the immune system to produce antibodies and memory cells without causing disease.
Why is herd immunity important?
When a large portion of the population is vaccinated, it reduces the spread of disease, protecting those who are not vaccinated.
Why can’t antibiotics treat viral infections?
Viruses live inside host cells and have different structures from bacteria; antibiotics target bacterial features and don’t work on viruses.
What is antibiotic resistance and why is it a problem?
Antibiotic resistance occurs when bacteria evolve to survive antibiotic treatment, making infections harder to treat and increasing the risk of disease spread.
How can the spread of infectious diseases be controlled?
Through hygiene, vaccination, clean water, isolation of infected individuals, and responsible use of antibiotics.
