Types of Interactions Chapter 1 Lessons 2 3

Types of Interactions Chapter 1: Lessons 2 & 3

Interactions with the Environment n n Mathematically, populations can grow exponentially…so why don’t they? Limiting Factors: the environment contains only so much food, water, living space, and other resources. n Example: if a population becomes too large, food becomes a limiting factor

n Carrying Capacity: the largest population that an environment can support n Example: if there are more organisms than an environment can support the limiting factors cause the population to get smaller

Interactions Among Organisms n n Competition: when 2 or more individuals or populations try to use the same limited resource. Competition may also occur within a population. Predators & Prey: n n Organism that is eaten is the prey Organism that eats the prey is the predator

n Predator Adaptations: in order to survive predators must be able to catch prey, and use a variety of techniques such as: Speed n Camouflage n n Prey Adaptations: in order to survive, prey must be able to avoid predation using techniques such as: Speed n Traveling in large groups n Camouflage n poisonous n

n n Symbiosis: a close, long-term association between 2 or more species Types: n Mutualism: both organisms benefit n n Commensalism: One organism benefits & the other is unaffected n n Coral & algae – algae produce the food and the coral provides a home for the algae Shark & remora – the remora rides around on the shark feeding off scraps Parasitism: one benefits & the other is harmed n Parasite lives off of the host. The host is weakened in the process: tapeworm & human

n Coevolution: a long-term change that takes place in two species because of their close interactions with one another. n Symbiotic relationships may result in coevolution n Flowers & pollinators show numerous examples & evidence of coevolution

Questions n What is mutualism? n n Give an example of a parasite n n …. What is carrying capacity? n n Symbiotic relationship in which both organisms benefit the largest population that an environment can support What is a limiting factor? n Any resource that restricts the growth of a population of organisms