U4 AOS 1 (first line)

Question 1

First line of defence

Answer 1

part of the innate immune system characterised by physical, chemical and microbiological barriers.

Question 2

Physical Barriers

Answer 2

Bark, closing stomata in plants.
Skin and mucus in animals.

Question 3

Chemical Barriers

Answer 3

Production of chemicals in plants.
Lysozymes and digestive enzymes, stomach acid, sweat, vaginal pH in animals.

Question 4

Microbiological Barriers

Answer 4

Presence of bacteria on the skin, gut and vagina.