Parasitology - Exam 3

Question 1

definition of parasitism

Answer 1

non-mutual symbiotic relationship between species where only one benefits

Question 2

key concepts of parasites

Answer 2

live in/on host, smaller than host, reduce host biological fitness, don’t kill their host normally, reproduce faster than host, use host for food/H2O/heat/habitat/transmission

Question 3

8 different types of host include:

Answer 3

host specific, broad host spectrum, definitive/final host (DH or FH), intermediate host (IH), biological vector, paratenic host (PH), transport host, aberrant/dead end host

Question 4

DH/FH

Answer 4

main host, sexual reproduction occurs within

Question 5

IH

Answer 5

other immature stages of a parasite

Question 6

PH

Answer 6

not required for life cycle, survival, transmission

Question 7

transport host

Answer 7

PH & IH can be these, help move parasite from A to B

Question 8

aberrant/dead end host

Answer 8

not the host the parasite belongs to, weird behavior, unable to properly develop/reproduce

Question 9

modes of infection

Answer 9

oral, skin penetration, injection, transplacental

Question 10

direct life cycle example

Answer 10

1 host; worms present in animal, eggs shed in feces, goes into environment, animal eats feces & gets infected

Question 11

indirect life cycle example

Answer 11

2+ hosts; worms in cat, eggs in feces, mouse eats feces, cat eats mouse

Question 12

sexual reproduction advantage

Answer 12

genetic diversity

Question 13

sexual reproduction disadvantage

Answer 13

longer life cycle, M & F parasites required

Question 14

asexual reproduction advantage

Answer 14

one (amplification), short life cycle

Question 15

asexual reproduction disadvantage

Answer 15

no genetic diversity

Question 16

benefits from the host: survival

Answer 16

heat, food, H2O, habitat,

Question 17

arrested development/hypobiotic stage

Answer 17

dormant, stop developing until parameters (temperatures) are right

Question 18

predilection site

Answer 18

preferred site in/on the host, each stage can have 1 food source, able to avoid immune system

Question 19

aberrant site

Answer 19

site in/on host which isn’t normal i.e.: eyeball

Question 20

parasite factors

Answer 20

number, location, migration, transmission (how it’s entering the animal), activity, production of toxic products,

Question 21

host response

Answer 21

previous exposure, type of host response (inflammatory, immune), nutritional status (malnourished = more likely to become ill), age of the host (size = baby vs adult)

Question 22

environmental factors

Answer 22

increase parasite, increase hypobiosis, decrease immunity, management, geographical location, weather

Question 23

-iasis

Answer 23

presence of parasite; healthy, no clinical signs

Question 24

-osis

Answer 24

disease caused by parasite

Question 25

helminth

Answer 25

worm, parasitic and nonparasitic, live extracellularly in GI tract & organs, passive/active ingestion of nutrients, stored as glycogen

Question 26

helminth sexual reproduction

Answer 26

male or female, hermaphrodite, oviparous (egg laying), viviparous (lay live young), don’t multiply within host (offspring must leave host), only way to get one is to eat one