BIO 100 Study Exam 3 - Chap 20 Communities and Ecosystems

Competitive Exclusion

Similar species have similar niches (resource requirements), they overlap so much that they cannot coexist indefinitely in the same place. (two species of cuckoo doves occupying different islands in the same area)

What is one of the major contributors to the extinction of species today?

Habitat destruction (more major than global warming)

What decreases biodiversity?

Introduction of invasive species

Interspecific competition (-/-)

Two or more species compete over the same limited resource (lion and cheetah both hunting gazelles)

Intraspecific competition (-/-)

Competition between its own population/same species (two birds competing over mate)

Mutualism (+/+)

Both species benefit from an interaction

Predation (+/-)

Interaction in which one kills another

Herbivory (+/-)

Consume plants

Biological magnification

Organica material decreases, the amount of toxins remains the same. As a result, the concentration of toxin increases as it is passed up the food chain.

Producer

Autotrophs (produces its own food - most plants, algae, fungi, some organisms)

Circle of the Trophic Structure:

Producer (grass), Primary Consumer (grasshopper), Secondary Consumer (bird), Teritary Consumer (snake), Quatemary/Apex Comsumer (owl), Decomposer (mushrooms), *then back to producer

Parasites and pathogens (+/-)

Lives in or on a host, must have a host to survive

Pathogen

Disease-causing bacteria, virus, fungi, or protist

Difference between infection and infestation

Inside vs. outside

Ecological succession

The replacement of one species by another (grass grows on sand dune, then shrubs, then trees)