click below
click below
Normal Size Small Size show me how
H U3 - Biodiversity
Higher - Unit 3 - Biodiversity
Question | Answer |
---|---|
What is genetic diversity | The number and frequency of alleles within a population |
Define Ecosystem diversity | Number of distinct ecosystems within a defined area. |
Define Species diversity | The species richness and relative abundance in an ecosystem. |
If there is a dominant species in an area, what happens to species diversity? | Species diversity is lowered. |
What are the 3 components to biodiversity? | Genetic, ecosystem and species |
What are the three threats to biodiversity? | Over exploitation, Habitat loss, invasive species |
Give two examples of over exploitation. | Over-fishing, Over-hunting |
What is the bottleneck effect? | When a large population becomes much smaller due to a natural distaster |
What is the disadvantage to the bottleneck effect? | 1. Small populations loose genetic variation for them to adapt to environmental change. 2. Causes inbreeding leading to poor reproductive rates. |
What is habitat fragmentation? | The clearing of habitats. |
What happens when there is degradation of the edges of habitats? | This increases competition between species, decreasing biodiversity. |
Habitat fragmentation makes habitats become ... | Smaller and more isolated. |
State the solution to habitat fragmentation. | Habitat corridors. |
What are habitat corridors? | Area of natural habitat that links two fragments together. |
What are the advantages to habitat corridors? | 1. Increases access to food or mates 2. Leads to recolonisation of fragments after local extinction. |
What is an introduced species? | When humans have moved species intentionally / accidentally to a new location. |
What is a naturalised species? | When introduced species become established in their new location. |
What is an invasive species? | When an organism spreads rapidly and eliminates the native species. |
Why are invasive species successful in their new location? | The new location is free from predators / pathogens / parasites. |
Why are native species eliminated by invasive species? | Invasive, prey on native species, outcompete native species and hybridise with native species. |