Name three forces that help prevent an introduced species from becoming an invasive species.
What are predators, disease, competition, parasites, limited resources, conditions within the environment outside the organism's range of tolerance?
200
The three conditions necessary for natural selection to occur.
more offspring born than can survive
genetic differences and traits
differences in fitness (survival and reproduction)
300
When environmental conditions change rapidly or severely enough that a species cannot adapt to the change, this occurs.
What is extinction?
300
a symbiotic relationship in which both participants benefit
What is mutualism?
300
A species that exerts a powerful influence over a community.
What is a keystone species?
300
three events that can trigger the process of secondary succession
What are forest fires, deforestation, and agriculture?
300
An ecosystem is rocked by a sudden and dramatic change. Name a possible consequence.
What could be extinction, succession, genetic drift?
400
This type of evolution is driven by resource partitioning among competing species.
What is character displacement?
400
The feeding relationship in which animals feed on plants
What is herbivory?
400
This is the most realistic model of feeding relationships within a community.
What is a food web?
400
A pioneer species in primary succession.
What is lichen or moss?
400
The connection between predator and prey populations
What is high prey numbers- predators rise?
prey down- predators down
predators down- prey up
predators up- prey down
500
This type of evolution occurs when only a few individuals remain following an extreme event. These few individuals now make up the entire gene pool. The gene pool has been changed by chance.
What is genetic drift?
500
This type of organism has a restricted range of tolerance for environmental conditions.
What is a specialist?
500
The greatest biomass is found within this level of an ecological pyramid.