defence against pathogens Flashcards
(16 cards)
What is the purpose of primary non-specific defenses?
Trap and prevent microorganisms from causing diseases
How does the skin act as a defense?
It acts as a physical barrier and produces antimicrobial chemicals that lower pH.
What do mucous membranes do?
They protect body openings by secreting mucus that traps pathogens and contains antimicrobial enzymes.
How does blood clotting prevent infection?
Clots form a fibrin mesh that seals wounds
What triggers inflammation?
Tissue damage releases molecules that increase blood vessel permeability and cause vasodilation.
How does inflammation help fight infection?
It brings white blood cells to the area and isolates pathogens through swelling and heat.
What happens during wound repair?
Skin cells divide and migrate
What are expulsive reflexes?
Automatic actions like coughing and sneezing that expel foreign objects and pathogens from the body.
What is the purpose of plant defenses?
To protect against infection by pathogens.
How does the waxy cuticle defend plants?
It acts as a physical barrier and prevents water accumulation
What role do plant cell walls play in defense?
They form a physical barrier against pathogens that pass the waxy cuticle.
What is callose and how does it help plants?
A polysaccharide that strengthens cell walls and blocks plasmodesmata to limit pathogen spread.
How do antimicrobial chemicals protect plants?
They kill or inhibit the growth of pathogens.
What are saponins and their function?
Chemicals that destroy the cell membranes of fungi and other pathogens.
What are phytoalexins and their function?
Chemicals that inhibit the growth of fungi and other pathogens.
How do plants defend against insect-borne viruses?
They produce chemicals toxic to insects
