Interactions and Niches Chapter 15.1

Definitions ___- organisms that are similar enough to produce offspring ___- group of organisms in the same species that live in a particular area ___- a natural environment where living things get all it needs to live

Definitions ___- the role living things play in a habitat ___- a group of populations that live in a particular area and ___ with one another

Five Levels of the Environment ___ – Climate & types of plants or animals ___ – Living and nonliving factors ___ – Numbers of populations ___ – Group of the same species ___ – Just one

Everything has a role Think of some jobs people have in Demarest (ex: police, fireman) How are these jobs important to the community? What skills are needed to support these jobs? What tools and resources are needed to do these jobs? How many people do these jobs (average)? Why are they so important? What factors impact these jobs?

Interactions Among Species 15.2

Predator and Prey ___- an animal that eats another ___- an animal that gets eaten Many prey animals ___ to protect themselves Prey populations affect the number and location of predator populations– ___

Competition ___- the struggle between individuals or different populations for a limited resource May occur ___ – Plants competing for light May occur ___ – Vines suffocating trees to get nutrients

Competition (continued)

Cooperation ___- an interaction in which organisms work in a way that ___ This usually refers to animals in the _____ (such as herds or packs) Some organisms have roles, such as ____

Cooperation

Symbiosis ___- The relationship between ___ who live together in a close relationship Affects organisms in three ways: – ____ – One species benefits while the other is ___

Mutualism, Commensalism, and Parasitism ___- a relationship between ___ that benefits both Ex: Bird eats bugs off zebra. Bird gets food. Zebra gets debugged!

Mutualism

Mutualism, Commensalism, and Parasitism ___- a relationship between two species in which ___

Commensalism

Mutualism, Commensalism, and Parasitism ____- a relationship between two species in which ___

Parasitism

Write This Down! Cooperation (same species) ___ Mutualism (different species) ___ Commensalism ___ Predator/Prey (Predation) ___ Parasitism ___ Key: + species benefits - species is harmed 0 species is unaffected

Population Change Over Time Chapter 15.3

Population Change Populations are always ___ Sometimes, populations ___ (___)and sometimes they ___ (___) ___- a condition that ___of a population in an ecosystem – Predators limit the number of prey – Too many or too little abiotic factors

Example In 1975, there were an estimated 1500 moose in Isle Royale National Park. All of a sudden, the wolf population in this park began to increase, feeding off of the moose. By 1980, the moose population had dropped to around 900. Likewise, the wolf population decreased because there were not enough moose to thrive off of

Balancing it All out ___- the maximum number of individuals that an ecosystem can support. – Food supply, – Room to live – Predator and prey relations

Succession ____- a gradual change in an ecosystem where ___. Ex: the buffalo used to run wild in the Midwest until hunters came along and replaced the buffalo population with humans