23. Mutualism & Parasitism

Question 1

Mutualism

Answer 1

Positive for species A and B

Question 2

Commensalism

Answer 2

Positive for A
Neutral for B

Question 3

Exploitation

Answer 3

Aka parasitism
Positive for A
Negative for B

Question 4

Parasite—host vs predator—prey/ herbivore—plant

Answer 4

Parasites form an intricate and long term relationship w the host

Question 5

Intermediate host

Answer 5

Parasite grows but does not reach sexual maturity

Question 6

Definite/primary host

Answer 6

Parasite reaches sexual maturity

Question 7

Red Queen hypothesis

Answer 7

Species have to evolve to keep up with the evolution of their parasites and vice versa

Can be compared to an arms race

Question 8

Arbuscular mycorrhizal fungi

Answer 8

-penetrate cortical cells of plant roots
- ~80% of plant spp

Question 9

Ectomycorrhizal fungi

Answer 9

• do not penetrate plant cortical cells
• ~2% of plant spp

Question 10

How do flowers attract butterflies/bees vs moths

Answer 10

Butterflies: bright colours, bees are red-blind— attracted to yellow or blue

Moths: heavy scent released at night

Question 11

Facultative mutualism

Answer 11

Occurs optionally, no dependance on specific partners (low risk of extinction if partner goes extinct)

Question 12

Obligate mutualism

Answer 12

Occurs by necessity, dependent on specific partner (high risk of extinction if partner goes extinct)

Question 13

Colony Collapse Disorder

Answer 13

Colonies lack enough worker bees to sustain themselves despite abundant honey

Question 14

Mutualism—parasitism continuum

Answer 14

Mutualism becomes reciprocal parasitism as natural selection begins to favour a species own fitness rather that simply “helping” organisms