Mutualism and Commensalism

Question 1

Positive Interactions

Answer 1

have influenced key events in the history of life
Continue to shape communities and influence ecosystem functions

Question 2

Obligate

Answer 2

a positive interaction that are highly species specific
This is not optional for either species

Question 3

Oligotrophic

Answer 3

It is lacking in nutrients
clear= no photosynthetic life present
Coral reefs are like a tropical rainforest

Question 4

Concept 15.1

Answer 4

In positive interactions, neither species is harmed and the benefits are greater than the costs for at least one species

Question 5

Commensalism

Answer 5

Millions of species form +/0 relationships with organisms that provide habitat
Ex. birds and elephants
Elephant isn’t being bothered or affected (0)
The birds are feeding on things that are being kicked off by the elephants (+)

Question 6

Mutualism

Answer 6

Mutually beneficial interaction between individuals of two species (+/+)
Ex. Bees and Pollen

Question 7

The Fungal Garden of a Leaf-Cutter Ant

Answer 7

Human farming 12,000 years ago
Ant fungal gardening 60 million years ago
Types of hyphae are swollen to form nutritive gongylidia that the ants feed on

Question 8

From benefactor to competitor

Answer 8

Take small flower forget me not
Live in swampy very wet areas
Alot of water causes soil to become anoxic -> bacteria eats up the oxygen
Want water for evaporation but also want it with oxygen
Given a shift in the environment causes a change in the temperature

Question 9

Concept 15.2

Answer 9

Each partner in a mutualistic interaction acts in ways that serve its own ecological and evolutionary interests

Question 10

A Facultative Mutualism

Answer 10

The interaction shifts from +/+ (mutualism) to +/0 (commensalism) or +/– (parasitism)
if consumption of honeydew by ants reduces treehopper growth or reproduction.
Mafia situation
Relationships shifts if there are no predators around

Question 11

Cheaters

Answer 11

individuals that increase offspring production by overexploiting their mutualistic partner
Can occur is moths lay too many eggs and the larvae eat too many seeds
Yuccas can selectively abort flowers with too many eggs before the moth larvae hatch

Question 12

Concept 15.3

Answer 12

Positive interactions affect the abundances and distributions of populations as well as the structure of ecological communities

Question 13

Corals Form Mutialisms with Symbiodimium

Answer 13

The coral provides the alga with a home
Nutrients (nitrogen and phosphorus) and access to sunlight
Alga: provides the coral with carbohydrates produced by photosynthesis
And indirect assistance with deposition of their calcium carbonate skeletons