4.2 biodiversity Flashcards
What is biodiversity?
The variety of living organisms in an area?
What is a species?
A group of similar organisms able to reproduce and give fertile offspring.
What is a habitat?
An area inhabited by a species. It includes physical factors (soil & temperature) and biotic factors (availability of food and predators)
What is habitat diversity?
the number of different habitats in an area.
What is species diversity?
The number of different species and the abundance of each species in an area.
What is genetic diversity?
The variation of alleles within a species. Eg the variation of alleles within the dog species gives rise to different breeds.
What is Simpson’s index of diversity?
A measure of diversity.
Why is low genetic diversity bad?
They might not be able to adapt to changes so the whole population can be wiped out in a single event. Populations may include isolated populations such as those in captivity.
What is genetic polymorphism?
Alleles of the same gene are found at the same point (a locus). Polymorphism describes a locus that has two or more alleles.
How do you calculate the proportion of polymorphic gene loci?
Number of polymorphic gene loci / number of loci.
How does human population growth affect global biodiversity?
Habitat loss, over exploitation as there’s a greater demand for resources, urbanisation can isolate species and pollution is killing species and habitats.
How is increased use of monoculture affecting global biodiversity?
Habitats are lost as land is cleared to make way for large fields (habitat diversity). Local and naturally occurring plants are seen as pests so are destroyed (species diversity). Heritage varieties of crops are lost because they are not planted.
How is climate change affecting global biodiversity?
Most species need a specific climate to survive, so a change in climate can mean a habitat can become uninhabitable. This causes a change in the range of some species. Some species may be made to migrate to more suitable areas causing a change in species distribution. Is there’s isn’t somewhere to migrate to the species becomes extinct.
What would happen if we lost species?
Organisms in an ecosystem are interdependent, so a loss of a species can disrupt the food chain and the nutrient cycles.
What is a keystone species?
a species on which other species largely depend on. They are often predators keeping the prey in check or modifiers (eg beavers) or hosts that provide a particular environment (eg palm trees)
Why should we maintain genetic resources?
We need them for: food, mainly from plants and animals; clothing, a lot of fibres are made from plants and animals; drugs, many are made from plant compounds; fuels, we use many micro organisms to produce fuel; and other industrial materials such as wood, paper, adhesives etc.
Why should we reduce soil depletion?
Continuous Monoculture causes soil depletion because the nutrients required by the crops are used up. The economic costs of soil depletion include increased spending on fertilisers and reduced yield.
What is in situ conservation?
In situ means on site conservation which involves protecting species in their natural habitat.
What are methods of in situ conservation?
Establishing protected areas such as national parks (restricts urban development and farming), preventing the introduction of species that threaten local biodiversity, protecting habitats (controlling water levels and trimming trees), promoting particular species and giving legal protection to endangered animals.
What is an advantage to in situ conservation?
Both the species and the habitat are conserved. Larger populations can be protected and there’s less disruption than removing organisms from the habitat.
What is a disadvantage to in situ conservation?
It is difficult to control some factors such as poaching, predators, disease or climate change.
What is ex situ conservation?
It means off site conservation. It involves protecting a species by removing part of the population from a threatened habitat.
What are some examples of methods of ex situ conservation?
Relocating organisms to a safer area, breeding organisms in captivity and reintroducing them into the wild, botanic gardens and seeds banks.
What is an advantage of ex situ conservation?
You can control the environment. Things like predation and hunting can be managed.
