7. Pathogens and Antibodies

Question 1

Definition of pathogens

Answer 1

are disease causing and infectious agents
includes bacteria, viruses, worms, fungi, protozoan parasite, prions
“germ theory” currently the recognised scientific theory for many diseases

Question 2

What is a culture?

Answer 2

micro-organisms, tissue, tissue cells or other living matter grown in a specially prepared nutrient medium eg. cell growth= a culture of bacteria

Question 3

Antigens

Answer 3

substances that interact with the immune system and the body to recognise pathogens present
proteins on pathogen’s surface or the toxins they produce may act as antigens

Question 4

Immune system

Answer 4

mammalian system that defends an organism against disease and other foreign tissue

Question 5

Levels of Defence

Answer 5

1st =barriers (innate response- non specific
2nd= chemical and general cellular defence (innate response)
3rd= humoral and cell-meditated responses

Question 6

Bacteria

Answer 6

prokaryotic, unicellular organisms
can infect almost any type of body
bacteria replicates via binary fusion and multiply quickly
eg. mengitis, tetanus, strep throat

Question 7

viruses

Answer 7

non-cellular pathogens
composed of genetic material (DNA and RNA) inside a protein coat
viruses cannot independently reproduce instead they insert their genetic material into host’s cell and use cell to replicate
eg. COVID-19 / rabies / AIDs

Question 8

Protozoa

Answer 8

unicellular eukaryotic organisms
can be free-living or parasitic
eg. malaria / sleeping sickness

Question 9

Prions

Answer 9

prions can be infectious proteins that destroy nerve cells in the brain
scrapie/ mad cow disease

Question 10

Fungi

Answer 10

eukaryotic organisms
have ling branching filaments called huphae
generally diseases caused by fungi are not life threatening
eg. thrush, ringworm, athlete’s foot

Question 11

Worms

Answer 11

multicellular eukaryotic organisms
parasites develop from an egg to larvae to an adult
develop slowly diseases caused= slow and chronic
eg. tapeworm-> malnutrition

Question 12

methods of transmission

Answer 12

direct through skin contact, bodily fluids, airborne particles, contact with faeces, touching a surface

Question 13

immune system lines of defence

Answer 13

inate/ non-specific ( first and second line of defence)
adaptive/ specific (third line of defence)