TAKS OBJECTIVE 3 TEK 12 (B) ORGANISMS RELY ON OTHER SPECIES FOR SURVIVAL: The student knows that interdependence and interactions occur within an ecosystem. The student is expected to INTERPRET interactions among organisms exhibiting predation, parasitism, commensalism and mutualism.

Focus Question: Organisms do not live in isolation. Explain the different relationships/ interactions ONE ORGANISM may have with OTHER ORGANISMS.

TAKS PRACTICE Which of the following is an example of mutualism? A A wasp injects its eggs inside the body of a caterpillar. The eggs hatch and eat the caterpillar. B A bird builds a nest in a tree. C A human uses a dog to protect a flock of sheep. The dog is given food and shelter. D A flower grows next to a bush.

Tundra biome, WHAT IF, cubs were not dependent of their parent? 1 EXAMPLE: consider the following… polar bears simply DID NOT form positive relationships with other animals? 3 polar bears did not have the physical ability to kill their prey? 2 OR

Symbiotic Relationships There are 4 symbiotic relationships: Mutualism Parasitism Commensalisms Predation

MUTUALISM Clownfish (+) vs. Sea Anemone (+) Butterfly (+) vs. Flower (+) Person 1 (+) vs. Person 2 (+) 1 2

PARASITISM Tick (+) vs. Dog (-) Mosquito (+) vs. Human (-) Tapeworm (+) vs. Human (-) Mite (+) vs. Plant (-)

COMMENSALISM Bromeliad plant (+) vs. tree trunk (0) Remora (+) vs. Shark (0) Cattle egret (+) vs. Buffalo (0)

PREDATION Snake (+) vs. Frog (x) Lion (+) vs. Buffalo (x) Sea Lion (+) vs. Salmon (x)

TAKS PRACTICE Which of the following best describes a difference between a mutualistic relationship and a parasitic relationship? F Parasitism harms both organisms, while mutualism harms only one organism. G Parasitism benefits only one organism, while mutualism benefits both organisms. H Parasitism involves only two organisms, while mutualism involves many organisms. J Parasitism continues for many generations, while mutualism is limited to one generation.

Beechdrops (Epifagus virginiana) are leafless plants that lack chlorophyll. Beechdrops get their nourishment from the roots of beech trees, which reduces the amount of nutrients available to the trees themselves. This interaction is best described as — A predatory B parasitic C commensalistic D mutualistic BEECHDROPS VS. TREE Beechdrops get nourishment and trees lose nutrients. Beechdrops benefit and trees are harmed…parasitism

TAKS PRACTICE A. Predation B. Parasitism C. Mutualism D. Commensalism In Central America there is a tree called bulhorn acacia (Acacia cornigera) that provides both food and shelter to a certain species of ant (Pseudomyrmex ferruginea). The ants live within the tree without causing it harm. In fact, the ants protect the tree by vigorously attacking and stinging other animals that try to eat it. This relationship is an example of- ANTS VS. TREE Remember, the ants protect the tree. The ants receive food and shelter. Each organism benefits…mutualism ANTS VS. TREE Remember, the ants protect the tree. The ants receive food and shelter. Each organism benefits

TAKS PRACTICE How does parasitism differ from predation? a. No organism is harmed in a parasitic relationship. b. No organism is harmed in a predator-prey relationship. c. Parasitism does not always result in the death of an organism. d. Parasitism does not occur among mammals.

1 According to the information in the box, which of these best describes the relationship between rhizobia and bean plants? A Parasitism B Opportunism C Commensalism D Mutualism BACTERIA VS. PLANT Remember, the bacteria get energy. The plants get nitrogen. Each organism benefits… Mutualism

Which of these best describes the relationship between epiphytes and trees? F Parasitism G Migration H Commensalism J Predation EPIPHYTES VS. TREE Epiphytes receive sunlight, they benefit. Trees are not affected…commensalism

EXPLANATION A relationship between two species in which one species (the parasite) nourishes itself to the disadvantage of the other species (the host). A relationship where one organism benefits while the other organism neither benefits nor is harmed.

EXPLANATION Commensalism (+,0): one organism benefits while the other organism is neither benefiting or harmed. Mutualism (+,+): relationship in which both organisms benefit. Parasitism (+,-): one organism benefits from the organism that is being harmed. Predation (+,x): one organism benefits from killing another organism Symbiosis: a close relationship between two or more organisms.