Interactions Among Living Things

1. Interactions Among Living Things A 7th Grade science presentation

2. Interactions • There are three major interactions among organisms: • Competition • Predation • Symbiosis

3. Predation • Predation is an interaction in which one organism kills and eats another organism. • The organism that does the killing is the predator. • The organism that is killed is the prey. • Predation can have a major effect on the size of a population.

4. Competition • Competition is the struggle between organisms to survive in a habitat with limited resources.

5. Symbiosis • Symbiosis is a close relationship between two species that benefits at least one of the species • There are three types of symbiotic relationships: • Mutualism • Commensalism • Parasitism

6. Mutualism • mutualism is an interaction between two or more species where both species derive benefit. • Ant-aphid mutualism: the aphids are protected from predators by the ants. The ants get the aphid secretion of honeydew as a reward.

7. Commensalism • Commensalism—is a relationship in which one species benefits and the other species is neither helped nor harmed. • The Remora fish (Echeneidea) is a long slender fish which has its dorsal fin modified as a sucker-like attachment organ. It attaches to the sides of larger fish and turtles using them as transport hosts but in addition, obtains food fragments dropped from the host.

8. Parasitism • An organism living on or inside another organism and harming it. • Head lice • Ticks • Fleas • Heart worm

9. Tape Worm

10. Athlete’s foot

11. Ring worm

12. Parasitism • The organism that benefits is called a parasite. • The organisms that it lives on or in is called a host.

13. Thank you • For paying attention and taking notes. • This concludes the slide show.