Iain Barr

Question 1

What is a parasite

Answer 1

Organisms that feed on other organisms
Dependent for food and development
Fitness effects are negative

Question 2

What forms can a parasite take

Answer 2

Bacteria
– Viruses
– Worms
– Flies
– Fungi

Question 3

5 common types of parasite

Answer 3

• Malaria
• Tapeworms
• Nematodes
• Wolbachia
• Brood parasites

Question 4

Describe a simple life parasite life cycle

Answer 4

Reproducing adults in the definitive host alternate with free-living egg or larval stages

Question 5

Describe a complex lifecycle

Answer 5

Include additional larval stages (which may reproduce asexually) in one or more intermediate hosts.

Question 6

What hurdles do parasites face

Answer 6

– Attachment to the host
– Withstand defences
– Competitors and predators

Question 7

What two forms of defenses do hosts have

Answer 7

Constitutive and inducible

Question 8

What are constitutive defences

Answer 8

Ones which are always present ie
Common to healthy animals
General protection
Wide range of parasites and disease

Question 9

What are inducible defences

Answer 9

responses activated through a previous encounter with a consumer or competitor that confer some degree of resistance to subsequent attacks.

Question 10

How can parasites limit populations

Answer 10

Limit;
Demographics
Body size
Distribution

Question 11

Life cycle of Leucochloridium paradoxum

Answer 11

Bird has the flatworm parasite
Passes eggs in droppings
Miracidia hatch
Infect snail living close to water
Moves into digestive system
Develop
Gather in the tentacles
Create eye-catching patterns
Bird eats the snail/tentacle
Snail may seek the light

Question 12

What is brood parasite

Answer 12

organisms that rely on others to raise their young.

Question 13

Types of brood parasites

Answer 13

Cuckoo and cuckoo wasps

Question 14

How are hosts adapted against brood parasitism

Answer 14

Removal of parasitic eggs by the host
Hiding of the nest
Identifying the parasite and killing/starving
Abandoning the nest and re-nesting

Question 15

What counter adaptations do brood parasites have against hosts

Answer 15

Laying mimetic eggs
Specialising on one host
Destroying nests if the eggs is rejected

Question 16

What are the 4 phenotypes of wolbachia

Answer 16

male killing (death of infected males). This selectively allows females to survive and more likely to reproduce even in the absence of males.
feminization (infected males grow as either fully fertile females or infertile pseudo-females)
parthenogenesis(reproduction of infected females asexually)
Cytoplasmic incompatibility (the inability of Wolbachia-infected males to successfully reproduce with uninfected females). This method causes a certain Wolbachia strain to be more dominant over the others.

Question 17

How is wolbachia passed down

Answer 17

Wolbachia are not found in mature sperms, but are found in mature eggs. So, the infection is carried along to offspring by infected females but not males.