1. KEY CONCEPT Organisms interact as individuals and as populations.

2. Competition and predation are two important ways in which organisms interact.
Competition occurs when two organisms fight for the same limited resource.
Intraspecific competition
Interspecific competition

3. Predation occurs when one organism captures and eats another.

4. There are three major types of symbiotic relationships.
Mutualism: both organisms benefit

5. There are three major types of symbiotic relationships.
Commensalism: one organism benefits, the other is unharmed
Human Our eyelashes are home to tiny mites
that feast on oil secretions and dead skin. Without harming us, up to 20 mites may be living in one eyelash follicle.
Demodicids Eyelash mites find all they need to survive in the tiny follicles
of eyelashes. Magnified here 225 times, these creatures measure 0.4 mm in length and can be seen only with a microscope. +
Organism benefits Ø
Organism is not affected
Commensalism

6. There are three major types of symbiotic relationships.
Parasitism: one organism benefits, the other is harmed
Organism benefits _
Organism is harmed
Hornworm caterpillar
The host hornworm will eventually die as its organs are consumed
by wasp larvae.
Braconid wasp
Braconid larvae feed on their host and release themselves shortly before reaching
the pupae stage of development.
Parasitism +

7. There are three major types of symbiotic relationships.
Parasitism meet their needs as ectoparasites (such as leeches) and endoparasites (such as hookworms)

8. Two robins eating worms is an example of
Mutualism
Commensalism
Competition
Parasitism

9. Predation is best described as
One organism capturing and eating another
Two organisms competing for limited resources
An interaction in which two species benefit from one another
An interaction in which one species benefits and the other is not affected

10. Aphids eat the sap from plants and excrete sticky waste that ants eat
Aphids eat the sap from plants and excrete sticky waste that ants eat. The ants protects the aphids from predators. This type of interaction is called
Mutualism
Commensalism
Competition
Parasitism

11. An oak tree provides a sparrow a place to build a nest
An oak tree provides a sparrow a place to build a nest. The nest neither benefits or harms the tree. What is the name for this type of relationship?
Mutualism
Commensalism
Competition
Parasitism

12. One difference between parasitism and predation is that parasites
Do very little to harm their hosts
Keep their hosts alive for a period of time
Attack the host only from the inside
Are not very big