C12: Communicable diseases

Question 1

how do viruses spread disease

Answer 1

• takes over cell metabolism to make new cells by inserting its genetic material into the host DNA
• uses it to make new cells that burst out of the cell, destroying it + spreads to infect other cells

Question 2

how do (parasite) protoctists spread disease

Answer 2

• they take over cells and break them, without taking over cell’s genetic material
• digests and uses the cell content as they reproduce

Question 3

how fungi spread disease

Answer 3

• digests living cells + destroys them

Question 4

how are communicable pathogens DIRECTLY transmitted between animals

Answer 4

direct contact: contact w bodily fluids, skin to skin, microbes from face.

inoculation: by a break in the skin, animal bite, puncture/wound
ingestion: by taking in contaminated foods, hand to mouth transfer

Question 5

how are pathogens INDIRECTLY transmitted between animals

Answer 5

fomites: inanimate objects eg. bedding, socks

droplet infection: droplets of saliva + mucus are expelled w coughing/talking/sneezing. if contaminated, passes on pathogens

vectors: transmits diseases from 1 host to another eg. mosquitos + malaria, water + diarrhoea

Question 6

how plants INDIRECTLY transfer com. diseases

Answer 6

soil contamination: infected plants leave pathogens/reproductive spores from protoctists/fungi in soil + infects the next crop

vectors: wind, water, animals, humans

Question 7

how plants DIRECTLY transmit com. diseases

Answer 7

direct contact of health yplant w infected plant. (eg. TMV, potato blight)