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.