1. SYMBIOTIC RELATIONSHIPS
Mutualism
Parasitism
Commensalism
Predation

2. ORGANISMS RELY ON OTHER SPECIES FOR SURVIVAL:
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.

3. Focus Question:
Organisms do not live in isolation. Explain the different relationships/ interactions ONE ORGANISM may have with OTHER ORGANISMS.
Students are expected to use their prior knowledge and list 4 different relationships: 1) both organisms benefit, 2) one organism benefits while other neither benefits or harmed, 3) organism benefits while harming other AND 4) organism KILLS other organism

4. 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.
*C: Mutualism – Both organisms (human and dog) benefit in the relationship/ interaction*
Students will be expected to apply their knowledge of mutualism, commensalism, and predation to situations they may not be familiar with.

5. Tundra biome, WHAT IF, EXAMPLE: consider the following… OR OR
cubs were not dependent of their parent? 1
polar bears did not have the physical ability to kill their prey? 2
polar bears simply DID NOT form positive relationships with other animals? 3
Organisms will have relationships within their ecosystem. In symbiotic relationships, ONE of the organisms WILL ALWAYS benefit; the behavior or outcome of the other organism will determine their relationship. OR OR

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

7. Clownfish (+) vs. Sea Anemone (+)
MUTUALISM
Person 1 (+) vs. Person 2 (+) 1 2
Butterfly (+) vs. Flower (+)
“ + ” means the organism benefits, “ 0 ” means the organism is neither benefiting nor harmed, “ – ” means the organism is harmed and “ x ” means the organism is killed

8. Tapeworm (+) vs. Human (-)
PARASITISM
Tick (+) vs. Dog (-)
Mite (+) vs. Plant (-)
“ + ” means the organism benefits, “ 0 ” means the organism is neither benefiting nor harmed, “ – ” means the organism is harmed and “ x ” means the organism is killed
Mosquito (+) vs. Human (-)

9. COMMENSALISM Remora (+) vs. Shark (0)
Bromeliad plant (+) vs. tree trunk (0)
Cattle egret (+) vs. Buffalo (0)
“ + ” means the organism benefits, “ 0 ” means the organism is neither benefiting nor harmed, “ – ” means the organism is harmed and “ x ” means the organism is killed

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

11. 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.

12. 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

13. TAKS PRACTICE
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-
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
*C* Mutualism. Two organisms interacting are the tree “Bulhorn Acacia” and the ant “Pseudomyrmex ferruginea.” The tree is protected (+) and the ant receives shelter (+).
A. Predation
B. Parasitism
C. Mutualism
D. Commensalism
ANTS VS. TREE
Remember, the ants protect the tree. The ants receive food and shelter. Each organism benefits…mutualism

14. 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. 

15. BACTERIA VS. PLANT
Remember, the bacteria get energy. The plants get nitrogen. Each organism benefits… Mutualism
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

16. 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

17. 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.

18. 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.