Organisms Can Interact in Different Ways

1. Organisms Can Interact in Different Ways You will learn: About different types of interactions in an ecosystem. How some species benefit from interactions. How some species are harmed by interactions.

2. Organisms Interact in Different Ways • The human community competes and cooperates. • Other biological communities do the same. • They share a habitat and resources in the habitat. • How different organisms interact depends on their relationship to each other.

3. Organisms Interact in Different Ways • A robin in a meadow picks at soil, pulls out worm and swallows it. • This is an interaction: one eats, the other gets eaten. • Organisms compete. • The robin had to compete with a chickadee to get the worm. • Organisms cooperate. • Ants work together to build a nest, collect food, defend their colony.

4. Question… • Name three ways organisms may interact with each other in an ecosystem. • Sharing food • A water source • Living in the same place

5. Predator and Prey • Predator: the animal that eats another • Can affect how members of prey populations are distributed • Wildebeests travel in herds for protection • Sick and old members are usually eaten • Prey: the animal that is eaten by a predator • Affect the location and number of predator populations • Ex. Some birds are predators feeding on insects. One factor that may affect the movement of birds is the availability of insects.

6. Competition • Competition: the struggle between individuals or different populations for a limited resource • May occur within the same species in an ecosystem • Ex. Plants compete with each other for space, light, and nutrients • Creosote bushes produce a toxin from their roots that prevent other Creosote bushes from growing

7. Competition • Also occurs between members of different species. • Ex. In Indonesia, vines called strangler figs compete with trees for light, water, and nutrients. Attaches to host tree, surrounds and eventually kills the tree. • Infer: Do you think the strangler fig could survive on its own?

8. Strangler Fig • What is it like on the floor of the rain forest? • Deep shade, damp, moist • What is at the top of the rainforest? • Lots of sunlight, leafy • What does the tree give to the fig vine? • Support so it can grow up towards the light

9. Competition • More Examples: • Hyenas and vultures compete for carcass’ • Wolves compete with each other over territory • What sort of resources do plants and animals compete for? • Space, light, water, and nutrients

10. Competition • Does NOT occur in all populations that share resources. • Many species live together without causing harm • Ex. Maple trees, Oak trees, and Birch trees all live together in the forest • Ex. Deer and rabbits live together

11. So…. • In what ways do organisms of the same or different species compete? • For food, space, water, other resources • What groups of organisms compete for mates? • Males or females of the same species

12. Cooperation • Cooperation: an interaction in which organisms work in a way that benefits them all • Some animals cooperate when hunting. Name some. • Killer whales, lions, wolves • Ants, bees and termites cooperate. • Live in colonies • Have different jobs/responsibilities

13. Formative Assessment • When animals mark their territory, how are they relating to other members of their species? • They are competing. • How are they relating when they hunt in packs? • They are cooperating within their species, and they are preying on another species.

14. Survival • The Survival of one species might depend on another species. • One species depends on the action or presence of another. • One species gets something it needs to survive • Food, reproductive help, protection • Symbiosis: the relationship between individuals of two different species • Symbiosis means “living together”

15. Symbiosis • May affect the partners in different ways: • Both species benefit from the relationship. • One species benefits while the other is not affected. • One species benefits while the other is harmed.

16. Symbiosis- Both Species Benefit • Mutualism: an interaction between two species that benefits both • Ex. Bees and flowers • The bee gets food, flower gets pollen from other flowers to produce seeds • Termites and protozoans • Termites are able to eat wood because of the protozoans that live in the termites gut and digest the wood. • The protozoans get a place to live and the termites get a food source that no other animal can eat.

17. Assessment • Which structures and behaviors of the hummingbird enable it to get nectar from the flower? • It has a long thin beak and can hover • How is the structure of the flower suited to its interaction with the hummingbird? • Its blooms are deep; it’s colorful; produces sweet food; pollen is spread to help reproduction • Why is this a good example of mutualism? • 2 different species interact. They each get a different need met.

18. Symbiosis- One Species Benefits • Commensalism: a relationship between two species in which one species benefits while the other is not affected • Ex. Orchids and mosses • Grow on tree trunks or branches • Get light and nutrients that run down the tree • The tree is not affected • Remoras hitch a ride on sharks and eat the sharks leftovers • The shark is not affected

19. Symbiosis- One Species is Harmed • Parasitism: a relationship between two species in which one species benefits while the host is harmed • Parasites are often tiny and feed off and weaken the host • Ex. Ticks, lice, mites are external parasites • Ex. Tapeworms and fungus

20. In Your Notebook Answer These Questions: • 1. Name two ways in which members of the same species interact. • 2. In what ways do members of different species interact? • 3. Give an example of each type of symbiotic relationship: mutualism, commensalism, and parasitism • 4. Think of a biological community near you, and give an example of how one population has affected another.