U4A1: 7B FIRST LINE OF DEFENCE

Question 1

part of the immune system

Answer 1

innate or non-specific

Question 2

physical barriers in plants

Answer 2

prevent pathogens from physically entering the organism.
eg. thick bark, waxy leaf cuticles, galls, thorns, closing stomata.

Question 3

chemical barriers in plants

Answer 3

harmful to the pathogen.
eg. phenols, oxalic acid, glucanases

Question 4

physical barriers in animals

Answer 4

block pathogens from entering organism.
eg. intact skin, mucous secretion

Question 5

chemical barriers in animals

Answer 5

make an environment unlivable for a pathogen.
eg. acidic sweat, lysozyme enzymes in tears, stomach acid

Question 6

microbiological barriers in animals

Answer 6

prevent the growth of pathogenic bacteria as they compete for space and resources.
eg. normal flora on skin, lower gastrointestinal tract and vagina.