Chapter 15 Flashcards
Biodiversity
The entire diversity of living organisms in an area
What is ESA
- Endangered Species Act
- law passed in 1973 to protect endangered species
Extinction
Complete loss of a species
How many mass extinctions have there been?
5 mass extinctions over the course of life on earth
Most severe threats to species loss are…
- loss or degradation of habitat
- intro of non-native species
- overexploitation of species
- pollution
Habitat
Is the place where a particular species lives and obtain resources for survival
Species area curve
Measures the relationship between the size of a natural area and the number of species it can support
Food Chain
Secondary consumers (Lion) -feed on- Primary Consumers (Deer) -feed on- Producers (Grass) -rely on- Energy from sun
Introduced Species
- Non-native species introduced to new area either purposely or accidentally
- destructive because they have not evolved with local species
Overexploitation
When human use of natural resources exceeds its reproductive rates
Eutrophication
- Excess fertilizer runoff leads to pollution of waterways
- excess growth of bacteria that depletes oxygen from water
Loss of species can lead to…
- loss of harvested resources (wood, fuel, etc)
- loss of medicinal sources (wild species)
Food web
When species interact with one another and their environment in complex ways
Mutualism
Relationship in which two species benefit from eachother
Commensalism
Relationship where one species benefits and the other is unaffected
Predator
Species that survives by eating other species
Keystone species
Key figures in determining the food web of an ecosystem
Decomposers
Return nutrients back into soil for use by plants (flys who decompose waste)
Genetic Variability
The sum of all the alleles and their distribution within species
Inbreeding depression
A decline in heterzygotes in small populations.
-cheetahs have low rate of cub survival because of poor quality of sperm due to inbreeding
Extinction Vortex
When a small population becomes stuck in inbreeding cycle that leads to extinction
