Transmission

Question 1

Identify the type of pathogen to which the term “die” does not apply and briefly explain your answer

Answer 1

Viruses are non-cellular and as cells are the building blocks of living organisms, these pathogens are not considered to be living

Question 2

what is direct transmission?

Answer 2

the spread of a pathogen from a host to a new host, without an intermediary (through direct contact)

Question 3

what are examples of diseases that are spread through direct transmission?

Answer 3

Athlete’s foot, TB, HIV and Bacterial meningitis

Question 4

what is droplet infection?

Answer 4

a form of direct transmission where physical contact between two individuals occurs through droplet sprays

Question 5

what diseases can be transmitted through droplet infection?

Answer 5

measles and TB

Question 6

what is an example of a common place that fungi can survive?

Answer 6

surfaces around swimming pools and in locker rooms

Question 7

what is turbidity?

Answer 7

the cloudiness of a fluid caused by large number of individual particles

Question 8

what is turbidity a key for testing for?

Answer 8

water quality

Question 9

what is transmission through direct and physical contact?

Answer 9

involves touching or kissing an infected individual or touching a contaminated surface

Question 10

what are examples of diseases that can be passed through direct physical contact?

Answer 10

Bacterial meningitis, ringworm and athlete’s foot

Question 11

how is HIV spread?

Answer 11

direct physical contact with blood, pre-ejaculate, semen, or vaginal fluids, all of which can contain the virus

Question 12

when can HIV be spread through non sexual transmission?

Answer 12

from an infected mother to the fetus during pregnancy, during childbirth by exposure to her blood or vaginal fluid, or to the baby through breast milk

Question 13

what are droplet infection, touching, kissing and sexual intercourse examples of?

Answer 13

of horizontal direct transmission

Question 14

what is vehicle- borne transmission?

Answer 14

transmission via an inanimate object or material which has become contaminated with the pathogen. The vehicle then contacts the individual’s body.

Question 15

what are some examples of objects linked to vehicle-borne transmission?

Answer 15

handkerchiefs, bedding and surgical instruments

Question 16

Name the type of pathogen that causes cholera and name the inanimate object or material that this pathogen contaminates

Answer 16

Vibrio cholerae is the species of bacteria that is mainly spread by unsafe water

Question 17

how is cholera mainly spread?

Answer 17

by fecal-oral transmission (feces in water or food consumed)

Question 18

what social factors can affect transmission?

Answer 18

Overcrowding
Levels of homelessness
Education
Diet
Ventilation in homes
and more…

Question 19

what is a vector?

Answer 19

a living organism that carries a pathogen from one host to another

Question 20

what is indirect transmission?

Answer 20

the passage of a pathogen from a host to a new host, via an intermediary organism that’s known as a vector

Question 21

what is transmitted through indirect transmission?

Answer 21

Malaria

Question 22

what is the Plasmodium parasite spread by?

Answer 22

female Anopheles mosquito

Question 23

what are obligate parasites?

Answer 23

an organism that cannot complete its life cycle without exploiting a suitable host

Question 24

where does there tend to be a greater variety of communicable diseases and why?

Answer 24

in regions with warmer climates as bacteria, fungi and Protoctista can grow and reproduce more rapidly in warm and moist conditions

Question 25

What do many fungi produce as a means of reproduction?

Answer 25

Spores ## Footnote Spores can be produced through sexual or asexual reproduction.

Question 26

What is the typical ploidy level of fungal spores?

Answer 26

Haploid ## Footnote Haploid spores grow into mature haploid cells through mitotic divisions.

Question 27

What process can lead to the formation of dikaryotic cells in fungi?

Answer 27

Fusion of two haploid cells ## Footnote Dikaryotic cells can result from the fusion of haploid spores.

Question 28

How are fungal spores often transmitted?

Answer 28

Airborne transmission ## Footnote Spores can be carried by the wind.

Question 29

What happens when spores of M.fijiensis are deposited onto banana leaves?

Answer 29

Germination and penetration through a stoma begins the formation of streaks ## Footnote These streaks are synonymous with black sigatoka.

Question 30

Fill in the blank: Spores are usually _______.

Answer 30

haploid

Question 31

True or False: Dikaryotic cells are formed from the asexual reproduction of fungi.

Answer 31

False ## Footnote Dikaryotic cells are formed from the fusion of two haploid cells.

Question 32

what is Totipotency?

Answer 32

the ability of a single cell to divide and produce all of the differentiated cells in an organism and a spore ## Footnote called a totipotent cell

Question 33

examples of a totipotent cells?

Answer 33

zygote and spores

Question 34

What are many pathogens present in?

Answer 34

Soil

Question 35

How do pathogens infect plants?

Answer 35

By entering through the roots

Question 36

Where do pathogens tend to reside once inside the plant?

Answer 36

Within the vascular tissues (xylem and phloem)

Question 37

What do pathogens feed off inside the plant?

Answer 37

Nutrients, such as sucrose

Question 38

What happens to infected leaves in deciduous trees?

Answer 38

They are shed but carry the pathogen back to the soil

Question 39

What occurs when the pathogen returns to the soil?

Answer 39

It can grow and infect another plant

Question 40

Explain why a pathogen that’s distributed with the seeds is particularly problematic

Answer 40

Many or all of the offspring are also infected