exam 4

Question 1

coevolution

Answer 1

evolution of 2 species in which each species acts as a selective pressure on the other. evolutionary change in 1 bring out evolutionary change in the other

Question 2

red queen hypothesis

Answer 2

interactions among species are a fundamental driver of evolution
a change in one is likely to select for change in another

Question 3

negative frequency dependent selection

Answer 3

rare variants slected

Question 4

trypanosoma brucei (african sleeping sickness) steps (5)

Answer 4

• tsetse fly feeds on human and transfers metacyclic trypomastigotes
• transform into slender typomastigotes and multiply in blood, lymph, spinal fluid
• some turn into trypomastigotes
• tsetse fly ingests stumpy trypomstigotes
• go through transformations and multiply, goes to salivary gland and sexually reproduce to form metacyclic trypomastigotoes

Question 5

what does tsetse fly trasnsmit

Answer 5

trypanosoma brucei (african sleeping sickness)

Question 6

tsetse fly steps 5

Answer 6

• male and female feed on blood
• one egg develops at a time
• larva emerges and feeds on milk, second egg starts to develop
• larva passed into soil, forms hard protective coat (puparium)
• puparium turns into fly

Question 7

trypanoma cruzi (chagas) steps 4

Answer 7

• triatomine takes blood meal and transfers metacyclic trypomatigotes in bite or mucus membranes
• amastigoes multiply in cytoplasm of infected tissue and burst out of cell and enter bloodstream or make new infection site
• triatomine ingests trypomastigoes and migrate to midgut and reproduce
• sexual reproduction, move to hindgut as metacyclic trypomatigotes

Question 8

what does triatominae (kissing bug) transmit

Answer 8

trypanosoma cruzi (chagas)

Question 9

leishamania steps (5)

Answer 9

• sand fly takes blood meal and injects promastigotes
• macrophages consume promastigotes and they become amstigotoes
• amastigotes rupture macrophage and get reeaten to continue cycle
• sandfly takes blood meal
• transform and sexually reproduce to promastigotes

Question 10

sand fly steps 3

Answer 10

• females take blood meal and lay eggs
• larva hatch and form matchstick hairs, molts
• pupa molts and becomes adult

Question 11

onchocerca volvulus (onchocerciasis) (river blindness) steps 5

Answer 11

-black fly takes blood meal and transmits L3 larvae
- migrate to subcutaneous tissue, molt + become adults, sexually reproduce
- produce unsheathed microfilaria consumed by fly
- move to thoracic muscle in fly, become L1 larvae
- molt to L2, L3, migrate to head

Question 12

what does the black fly transmit

Answer 12

onchocerciasis (river blindness)

Question 13

black fly steps 4

Answer 13

• females take blood meal and deposits eggs on water surface where they sink
• eggs hatch and attach to silk mat, 6-7 molts
• spins cocoon and pupates
• adults emerge from cocoon

Question 14

extirpation

Answer 14

extinction of a population

Question 15

parasite crossover

Answer 15

introduced nonindigenous host with nonindigenous parasite gives parasite to indigenous species

Question 16

parasite spillback

Answer 16

introduced nonindigenous host becomes a parasite reservoir and increases indigenous host infection

Question 17

parasite host hypothesis

Answer 17

loss of parasites during invasion of new range can give a competitive advantage

Question 18

3 categories of parasite control techniques

Answer 18

interventions to reduce parasite transmission
anti parasitic drugs
vaccines

Question 19

anisakis steps 5

Answer 19

• marine mammals excrete unembryonated eggs that become embryonated in water and hatch
• crustaceans ingest larva
• crustaceans eaten by fish/squid, larvae migrate to muscle tissues
• humans may eat them and become accidental hosts
• marine mammals eat fish, larva reach maturity and sexually reproduce

Question 20

how did ddt work

Answer 20

opening sodium channels on neurons to kill insects
lipophilic, bioaccumulates at top of food chain
interferes with Ca deposition in eggs

Question 21

what are pyrethroids

Answer 21

similar to ddt but less harmful to environment
resistance built

Question 22

biological control example

Answer 22

purposeful introduction of an organism into a habitat in order to have a negative effect on + control a population of another organism
mosquito fish, sterile insect technique

Question 23

theraputic index

Answer 23

toxic dose / effective dose

Question 24

how do antiparasitic drugs work

Answer 24

target some aspect of parasite metabolism that differs from that of the host organism
likely to have some toxicity to our cells as well

Question 25

what are standards vaccines must have 5

Answer 25

establish immunological memory
safe
protective (sustained)
activate B + T cells
practical (stable, cheat, easy to administer)