Back to AI Flashcard MakerBiology /LGS A-Level OCR Biology - Unit 4 - Biodiversity Part 4
Outline the process of mark-release-recapture
organisms are captured and marked with a non-toxic marking
time is allowed for organisms to redistribute
the organisms are recaptured and the number of marked animals is compared to the number of unmarked animals
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Key Terms
Term
Definition
Outline the process of mark-release-recapture
organisms are captured and marked with a non-toxic marking
time is allowed for organisms to redistribute
the organisms are recaptured and the number o...
What is the relationship between diversity of an ecosystem and stability of the ecosystem?
Greater the species diversity, the greater the stability of an ecosystem (usually)
What is the usual effect of pollution on biodiversity?
Pollution usually reduces biodiversity
Why can low species diversity indicate pollution is present?
Pollution usually results in harsh conditions, so few species tend to dominate, and biodiversity is reduced
What is Simpson's index of diversity?
A measurement of biodiversity which takes into account both species richness and species evenness
What is the range of values for Simpson's biodiversity index?
Simpson's biodiversity index always results in a value between 0 and 1
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| Term | Definition |
|---|---|
Outline the process of mark-release-recapture | organisms are captured and marked with a non-toxic marking
time is allowed for organisms to redistribute
the organisms are recaptured and the number of marked animals is compared to the number of unmarked animals |
What is the relationship between diversity of an ecosystem and stability of the ecosystem? | Greater the species diversity, the greater the stability of an ecosystem (usually) |
What is the usual effect of pollution on biodiversity? | Pollution usually reduces biodiversity |
Why can low species diversity indicate pollution is present? | Pollution usually results in harsh conditions, so few species tend to dominate, and biodiversity is reduced |
What is Simpson's index of diversity? | A measurement of biodiversity which takes into account both species richness and species evenness |
What is the range of values for Simpson's biodiversity index? | Simpson's biodiversity index always results in a value between 0 and 1 |
What does a higher result of Simpson's diversity index indicate? | A more diverse habitat. The higher the value of Simpson's diversity index, the more diverse the habitat |
What are the features of an area with low biodiversity? | relatively few successful species
stressful and/or extreme conditions
few species live in habitat and those which do have very specific adaptations
relatively simple food webs
change to whole ecosystem has major effects |
What are the features of an area with high biodiversity? | a large number of successful species
relatively benign/not stressful conditions
many species live in the habitat
complex food webs
often relatively small effect on ecosystem if there is a change to ecosystem |
What is the effect of greater genetic biodiversity on the survival of a species? | Greater genetic biodiversity increase the change of the long term survival of a species |
Why does greater genetic biodiversity increase the chance of long term survival for a species? | better able to adapt to changes in their environment
there are likely to be some organisms within the population that carry an advantageous allele
which enables them to survive in the altered conditions |
How can genetic diversity of a population be increased? | mutations in DNA of an organism
| - interbreeding between different populations (gene flow) |
How can genetic biodiversity of a population be decreased? | selective breeding
captive breeding
natural selection
genetic bottleneck
genetic drift |
How does deforestation reduce biodiversity? | reduces the number of animal species in an area as it destroys their habitat
food sources are reduced/removed
animals are forced to migrate to other areas |
Give 3 ways human have reduced biodiversity | deforestation
agriculture
climate change |
How does removal of hedgerows reduce biodiversity? | reduces number of plant species in an area
destroys habitat for animals
reduces/removes food sources |
Give 3 ways agriculture reduces biodiversity | removals of hedgerows
monoculture
use of pesticides and herbicides |
What is monoculture? | The farming technique where only one crop is grown |
What is global warming? | A gradual increase in overall temperature of the earth due to pollutants released and the greenhouse effect |
What is climate change? | A change in global or regional climate patterns due to increasing levels of CO2 in the atmosphere produced by use of fossil fuels |
Give 4 ways climate change will reduce biodiversity | rising sea levels flood low lying land
insect life cycles and population would change
saltwater would flow further up rivers
in some areas rainfall would lower |
What are the 3 categories of reasons for maintaining biodiversity? | ecological
aesthetic
economic |
Give an ecological reason why biodiversity should be maintained | -all organisms are interdependent on others for survival, removal of one species may have significant effect on others |
Give 2 aesthetic reasons why biodiversity should be maintained | natural world provides inspiration for people
| - studies have shown that patients recover more quickly when supported by the natural environment |
Give 4 economic reasons why biodiversity should be maintained | species with potential economic importance may become extinct before they are discovered
continuous monoculture depletes soil of nutrients and so makes the ecosystem more fragile
greater biodiversity means greater potential for the manufacture of different products in the future high biodiversity provides protection against abiotic stress factors and disease |