Transmission and host behaviour

Question 1

What is parasite fitness determined by?

Answer 1

(no. successful progeny/ offspring)

Question 2

Give 2 examples of a parasite manipulating host behaviour

Answer 2

leucochloridium paradoxum
- parasites migrate to eyestalks of snails
- mimic caterpillar
- manipulate light perception
- ingested by birds
\+
ribeiroia ondatrae
- manipulate frog limb development so they cannot walk or swim and are eaten by shore birds1

Question 3

Nematodes infect (a) ants, leading to a (b) colouration of the abdomen, attracting birds as they think they are fruit (c).

Answer 3

a) turtle
b) red
c) berries

Question 4

Give 2 examples of a physiologically altering parasite

Aim?

Answer 4

a) plerocercoids of tapeworms cause mice to produce plerocercoid growth factor to make mouse grow excessively and attract predators

Question 5

Taenia (a) causes a (b) cyst to grow in sheep brain, (their (c) host) which causeds sluggish behaviour.

Answer 5

a) multiceps
b) hydatid
c) intermediate

Question 6

What does toxoplasma gondii to do cause behaviour changes in rodents?

Answer 6

creates cysts in brain

Question 7

How does toxoplasma gondii affect rodent behaviour?

Answer 7

1) decreased fear response to novel objects
- increased exploratory behaviour
- reduced vigilance for predators
- increased overall anxiety
- attraction to cats via cat specific odour receptors (L-DOPA)

Question 8

Trypanosoma (a) (kissing bug is the vector) is an example of (b) altering a host. It is released into the (c) while feeding on a host, which elicits an (d) allowing it to be scratched into the skin.

Answer 8

a) cruzi
b) physiologically
c) faeces
d) itch

Question 9

How are HAIR WORMS examples of what form of host manipulation? What is the host

Answer 9

• enslavers
• the host is a cricket
• the adults are aquatic and juvenile worms live in crickets
• worm manipulates host into water at night before 3am and leaves host to die

Question 10

Infected mayflies by the parasite (a) nematodes are forced to become females by a hijack of the (b) system and lay eggs over (c).

Answer 10

a) Mermithid
b) endocrine
c) water