4.2 Biodiversity Flashcards
What is biodiversity?
The variety of living organisms in an area.
What are the three types of biodiversity?
- Habitat
- Genetic
- Species
What is species richness?
The number of different species in an area. The higher the greater species richness.
What is species evenness?
The relative abundance of each species in an area. The more similar the population sizes the greater the evenness.
What causes greater biodiversity?
Higher species richness and the better the species evenness the better the biodiversity.
What is a habitat?
The area has inhabited by a species.
What is the formula for simpson index of diversity?
D = 1 - ( ∑ (n/N)^2 )
What is genetic diversity?
A measure of the biodiversity within a species.
What is the problems with having low genetic diversity?
- May not be able to adapt to a change in the environment and the whole population could be wiped out by a single event.
What is polymorphism?
Describes a locus that that has two or more alleles.
What types of factors affect biodiversity?
- Human population growth
- Monoculture
- Climate change
How does human population growth affect biodiversity?
- Decreasing biodiversity because of:
• Habitat loss due to land being used for housing and food production.
• Over-exploitation of resources like food water and energy.
• Urbanisation and road building can isolate species decreasing their genetic diversity.
• Pollution kills species and destroys habitats.
How has monoculture affected biodiversity?
- Decline in biodiversity due to:
• Habitat loss as land is cleared to make way for large fields like palm oil plantations.
• Loss of local plants and animals like weeds and pests so destroyed with herbicides and pesticides reducing species diversity.
• Loss of heritage varieties of crops as they do not make enough money do not grown.
How does climate change affect biodiversity?
- Climate changes affect the environmental conditions and make areas uninhabitable and cause a change in the range of species in that area.
- This will decrease biodiversity.
What are endangered species?
Species that are at risk of extinction due to low population size and/or a threatened habitat.