4.1.1 a communicable diseases

Question 1

what is the shape and function of cocci?

Answer 1

small and round
less surface area so can survive in dryer environments

Question 2

what is the shape and function of spirillum?

Answer 2

spiral cells
move in a corkscrew motion so meet less resistance from surrounding water

Question 3

what is the shape and function of bacilli and vibrio?

Answer 3

greater surface area to volume ratio so can easily take up nutrients from dilute solutions
shaped like tubes with rounded ends

Question 4

how long does it take for one bacterium to replicate?

Answer 4

20 minutes

Question 5

how do bacteria reproduce and why?

Answer 5

binary fission
no nucleus so mitosis doesn’t occur

Question 6

what are the problems of bacteria reproducing so quickly?

Answer 6

food spoils quickly
spread of disease can happen faster

Question 7

how do bacteria cause disease?

Answer 7

produce toxins which causes symptoms by cell damage eg cell membranes, enzymes or genetic material

Question 8

what happens during the lytic cycle?

Answer 8

the virus attaches to a specific host cell
genetic material from virus is injected into host cell
viral genes cause the host cell to make new viruses
host cell splits open releasing the new viruses and killing the cell

Question 9

what is a phage?

Answer 9

virus that infects and replicates within bacteria and archaea

Question 10

what is the lysogenic cycle?

Answer 10

phage infects a bacterium and inserts its DNA into the bacterial chromosome allowing the phage DNA to be copied and passed on along with the cell’s own DNA

Question 11

what type of pathogen causes tuberculosis?

Answer 11

Mycobacterium tuberculosis
which is a bacterium

Question 12

what organisms are affected by tuberculosis?

Answer 12

humans, cows, pigs, badgers, deer

Question 13

how is tuberculosis spread?

Answer 13

through the air from one person to another

Question 14

what are the symptoms of tuberculosis?

Answer 14

damages and destroys lung tissue and suppresses the immune system
cough that lasts more than 3 weeks
feeling tired
high temperature
loss of appetite and weight loss

Question 15

how is tuberculosis prevented and cured?

Answer 15

prevented by improving living standards and vaccinations
cured by antibiotics

Question 16

what is type of pathogen is bacterial meningitis caused by?

Answer 16

commonly caused by Streptococcus pneumonia which is a bacterium

Question 17

what organisms are affected by bacterial meningitis?

Answer 17

humans

Question 18

how is bacterial meningitis spread?

Answer 18

from person to person through the droplets of respiratory or throat secretions

Question 19

what is bacterial meningitis an infection of?

Answer 19

the meninges of the brain which can spread to the rest of your body causing blood poisoning and rapid death

Question 20

what are the symptoms of bacterial meningitis?

Answer 20

blotchy red rash that does not disappear when you press a glass to it

Question 21

how can bacterial meningitis be prevented?

Answer 21

vaccines can prevent some forms

Question 22

what type of pathogen causes ring rot?

Answer 22

Clavibacter michiganensis which is a bacterium

Question 23

what organisms are affected by ring rot?

Answer 23

potatoes
tomatoes
aubergines

Question 24

how is ring rot spread?

Answer 24

contact with infected tubers particularly if tuber is damaged

Question 25

what are the symptoms of ring rot?

Answer 25

damages leaves, tubers and fruit and can destroy up to 80% of the crop

Question 26

what is the cure for ring rot?

Answer 26

no cure

Question 27

what type of pathogen causes AIDS?

Answer 27

Human immunodeficiency virus which targets T helper cells in the immune system of the body

Question 28

what organisms are affected by AIDS?

Answer 28

humans chimpanzees gibbon apes rabbits

Question 29

how is AIDS spread?

Answer 29

from body fluids of an infected person including blood, breast milk, semen and vaginal fluids

Question 30

what does AIDS do to the body?

Answer 30

gradually destroys immune system so affected people are open to other infections like TB, pneumonia and some types of cancer

Question 31

how is AIDS prevented and cured?

Answer 31

no vaccines and no cure but anti-retrovirol drugs slow down the progress of the disease

Question 32

what is influenza caused by?

Answer 32

influenza virus

Question 33

what organisms are affect by the influenza virus?

Answer 33

humans pigs chickens

Question 34

how is influenza spread?

Answer 34

virus is spread through droplets

Question 35

what does the influenza do to the body?

Answer 35

kills the ciliated epithelial cells leaving the airways open to secondary infection severe secondary bacterial infections can occur on top of the original viral infection

Question 36

what type of pathogen causes tobacco mosaic virus?

Answer 36

viral plant pathogen

Question 37

what organisms does tobacco mosaic virus affect?

Answer 37

tobacco plants and around 150 other species

Question 38

how is tobacco mosaic virus spread?

Answer 38

infected plants rubbing against healthy plants or contaminated tools or workers hands

Question 39

what does tobacco mosaic virus do to the plants?

Answer 39

damages leaves, flowers and fruit stunts growth and reduces yields can lead to almost total crop loss

Question 40

what is the cure for tobacco mosaic virus?

Answer 40

no cure but resistant strains are available

Question 41

what type of pathogen caused malaria?

Answer 41

protoctist plasmodium

Question 42

what does organisms does malaria affect?

Answer 42

reptiles birds mammals

Question 43

what spreads malaria?

Answer 43

bite of an infected female Anopheles mosquito

Question 44

what does malaria do to the infected organism?

Answer 44

makes organism weak and vulnerable to other infections

Question 45

how is malaria cured and prevented?

Answer 45

no vaccine and limited cures

Question 46

what are the symptoms of malaria?

Answer 46

high temperature headaches feeling very tired muscle pains

Question 47

what type of pathogen causes potato/tomato blight?

Answer 47

caused by a water mould which is a fungus-like protoctist

Question 48

what organisms are affected by the potato blight?

Answer 48

potatoes tomatoes aubergines other members of the potato family

Question 49

how is potato blight spread?

Answer 49

carried by the wind and the rain

Question 50

what does potato blight do to the organism?

Answer 50

hyphae penetrate host cells and destroys leaves, tubers and fruits

Question 51

how do we cure and prevent potato blight?

Answer 51

no cure but resistant strains exist and chemical treatments can reduce infection risk

Question 52

what type of pathogen causes black Sigatoka?

Answer 52

Mycosphaerella fijiensis which is a fungus

Question 53

what organisms does black Sigatoka affect?

Answer 53

banana

Question 54

how is black Sigatoka spread?

Answer 54

rain splashes and wind borne spores during wet, humid, windy conditions

Question 55

what does black Sigatoka do to the organism affected?

Answer 55

hyphae penetrate and digest cells which turn the leaves black

Question 56

how is black Sigatoka cured and prevented?

Answer 56

no cure but resistant strains are being developed fungicide treatment and good husbandry can control the spread of the disease

Question 57

what type of pathogen causes ringworm?

Answer 57

fungi called Trichophyton

Question 58

what organisms does ringworm affect?

Answer 58

dogs cattle cats sheep goats pigs rodents rabbits birds humans

Question 59

how is ringworm spread?

Answer 59

contact with objects or surfaces that an infected person or animal has touched or rubbed against

Question 60

what are the symptoms of ringworm?

Answer 60

causes grey-white, crusty, infectious circular areas of skin rash may be scaly, dry, swollen or itchy

Question 61

what is the cure for ringworm?

Answer 61

anti fungal creams

Question 62

what type of pathogen causes athletes foot?

Answer 62

fungi called Tinia pedia

Question 63

what organisms are affected by athletes foot?

Answer 63

humans

Question 64

how is athletes foot spread?

Answer 64

through contact with contaminated surfaces

Question 65

what are the symptoms of athletes foot?

Answer 65

ringworm that grows on and digests the warm, moist skin between the toes causes cracking and scaling which is itchy and sore

Question 66

what is the cure for athletes foot?

Answer 66

anti fungal creams