Community Interactions CH 37

Community All the populations that _____________________________ __________ is the type of place where individuals of a species typically live Type of habitat shapes a _________________________

Factors Shaping Community Structure ___________________________ Available foods and ______________ Adaptations of species in community ______________________ __________________of species Physical disturbances

Niche Sum of activities and relationships in which a species engages to __________________________________ __________________________________

Species Interactions Most interactions are______; have no effect on either species _______________ helps one species and has no effect on the other Mutualism helps ________________

Species Interactions __________________has a negative effect on both species _________________________both benefit one species at a cost to another

Symbiosis ________________for at least some part of the life cycle Commensalism, mutualism, and parasitism are forms of ______________

Mutualism Both species ___________ Many examples in nature Some mutualisms are ___________; partners depend upon each other

Yucca and Yucca Moth Example of an obligatory mutualism Each species of yucca is _______________________________ ______________can grow only in that one species of yucca

Mycorrhizae Obligatory mutualism between ___________________________ Fungus supplies _____________to root Root supplies ___________ to fungus

Improved water and mineral uptake in mycorrhizal plants.

Commensalism One species _____________________________ Many examples in nature

Periwinkle on Seaweed (worksheet study)

Competition __________ - between different species _____________ - between members of the same species _____________ competition is most intense

Forms of Competition Competitors may have equal access to a resource; compete to exploit resource more effectively One competitor may be able to control access to a resource, to exclude others

Competitive Exclusion Principle When two species compete for identical resources, __________________________________ __________________________________

Paramecium caudatum Paramecium aurelia

Competitive Exclusion Expt Paramecium caudatum Paramecium aurelia

Predation Predators are animals that feed on ______________________________ Predators are free-living; _______________________________

Coevolution _____________promotes traits that help prey escape predation It also promotes traits that make predators more ____________________________

Prey Defenses ___________________ ____________________ _______________ __________________

Predator Responses Any adaptation that protects prey may select for predators that can overcome that adaptation Prey adaptations include ________, _________, and ways to avoid _________________

Parasitism Parasites drain nutrients from their _____________________________ Natural selection favors parasites that _______________________________

Types of Parasites ______________

Hog Sphinx Moth caterpillar, seen here on Smartweed, has been parasitized by Cotesia congregata, a braconid that lays its eggs in the caterpillar

Cobweb Spider (plus Ichneumonid wasp parasite)

Balanophora fungosa produces no chlorophyll so it is unable to manufacture its own food from sunlight so it lives parasitically on the roots of certain plants.

Immature Spined Assassin bug with what looks like tachinid egg parasites.

Hyalophora cecropia caterpillar

Tarantula Hawk Wasp

Tarantula Hawk Wasp in action!