Week 7

Question 1

positive interactions

Answer 1

One or both species benefit and neither is harmed.

Question 2

mutualism

Answer 2

Mutually beneficial interaction between individuals of two species

Question 3

commensalism

Answer 3

The interaction between individuals of two species in which one benefits, and one neither benefits/harmed.

Question 4

symbiosis

Answer 4

A relationship in which individuals of the two species live in close physiological contact with each other.

Question 5

mycorrhizae

Answer 5

Symbiotic associations between plant roots and various types of fungi that are usually mutualistic.

Question 6

ectomycorrhizae

Answer 6

Fungal partner grows between root cells and forms a mantle around the exterior of the root; hyphae in the mantle often extend short distances into the soil.

Question 7

arbuscular mycorrhizae

Answer 7

Partner grows farther into the soil, and it grows between some root cells while penetrating cell walls of others.

Question 8

trophic mutualism

Answer 8

Mutualist receives energy or nutrients from its partner.

Question 9

habitat mutualism

Answer 9

One partner provides another right shelter or favorable habitat.

Question 10

service mutualism

Answer 10

One partner performs and ecological service for another (e.g. pollination, dispersal).

Question 11

masting

Answer 11

When plants avoid herbivory by producing great numbers of seeds in some years, and few or no seeds in other years.

Question 12

compensation

Answer 12

When removal of plant tissues stimulates a plant to produce new tissues.

Question 13

secondary compounds

Answer 13

Production of chemicals to reduce herbivory.