Mutualism

Question 1

types of mutualism

Answer 1

direct and indirect

• transport
• nutritional
• propagules
• gamete mutualism
• protective

Question 2

plant mutualism

Answer 2

bacteria, fungi and animals

benefits:

• nitrogen fixation
• enhanced nutrient and water uptake
• pollination (gamete mutualism) and seed dispersal (propagules)

Question 3

mycorrhizal fungi - plants

Answer 3

nutritional

• increase access to water, nitrogen, phosphorous
• fungi get energy rich root exudates
• balance sheet can be altered by availability of nutrients

Question 4

plant-ant protection

Answer 4

protective

- plants give food and shelter for protection

Question 5

coral mutualists

Answer 5

corals depend on algae and animals

Question 6

algae - zooxanthellae (coral)

Answer 6

provide coral energy for nutrients, especially nitrogen (scarce in ocean)
coral chemically solicits release of organic compounds from algae and controls its growth

Question 7

animals - crabs and shrimps (coral)

Answer 7

protect in exchange for food and shelter

Question 8

evolution of mutualism

Answer 8

theory predicts that mutualism will evolve where the benefits exceed the costs

• weigh herbivory by ants against need for protection
• more likely when alternative defences are low