3.1 Biodiversity & Evolution (DP IB Environmental Systems & Societies (ESS): SL): Flashcards
0Still learning
Know0
Define biodiversity.
Was this flashcard helpful?
Cards in this collection (50)
Define biodiversity.
Biodiversity is the total diversity of living systems, which exists at several levels.
At what three levels can biodiversity be assessed?
Biodiversity can be assessed at the level of habitats and ecosystems, species, and genes.
Define habitat diversity.
Habitat diversity is the range of different habitats within a particular ecosystem or biome.
Which ecosystem is a classic example of high habitat diversity?
A coral reef is a classic example of high habitat diversity, containing many microhabitats and niches.
True or False?
Large sandy deserts typically have high biodiversity.
False.
Sandy deserts typically have low biodiversity because conditions are largely uniform throughout the area.
Define species richness.
Species richness is the number of species within an ecosystem.
Besides the number of species present, what else does species diversity measure?
Species diversity also measures the evenness of abundance across the different species present.
Genetic diversity helps a population to changes in the environment.
Genetic diversity helps a population adapt to changes in the environment.
Why are the pine forests of Florida vulnerable to ecosystem collapse?
The pine forests of Florida are dominated by one or two tree species, making them vulnerable to collapse if a pathogen targets one.
Define genetic diversity.
Genetic diversity is the diversity of genes found within the individuals of a species.
True or False?
Genetic diversity only occurs between different populations of a species, not within a single population.
False.
Genetic diversity occurs both between populations and within a single population of a species.
Why is high biodiversity important for an ecosystem?
High biodiversity increases an ecosystem's resilience, helping it resist environmental change and avoid tipping points.
Define evolution.
Evolution is the cumulative change in the heritable characteristics of a population or species over time.
Define natural selection.
Natural selection is the mechanism driving evolutionary change, whereby the best-adapted individuals in an environment are more likely to survive and reproduce.
Who proposed the theory of natural selection?
Charles Darwin proposed the theory of natural selection.
True or False?
The selection pressures acting on a species always stay the same over time.
False.
An environment and its selection pressures can change over time, so different characteristics may become advantageous.
What causes competition for resources in natural selection?
Organisms produce more offspring than the environment can support, causing competition for limited resources.
Advantageous characteristics are passed on to at a higher rate than less suitable characteristics.
Advantageous characteristics are passed on to offspring at a higher rate than less suitable characteristics.
In the rabbit fur colour example, why do brown-furred rabbits have a selection advantage over white-furred rabbits?
Brown-furred rabbits camouflage better from foxes than white-furred rabbits, making them more likely to survive and reproduce.
Which moth species is a well-known example used to illustrate natural selection?
The peppered moth is a well-known example used to illustrate natural selection.
Define speciation.
Speciation is the generation of new species through evolution.
When are two isolated populations of a species considered separate species?
They are considered separate species once they can no longer interbreed to produce fertile offspring.
True or False?
Organisms that are less well-adapted to their environment can never survive or reproduce.
False.
Less well-adapted organisms can still survive and reproduce, but their chances are lower than better-adapted individuals.
What is the source of the variation between individuals that natural selection acts upon?
The variation between individuals arises from differences in genes, also known as genetic diversity.
Define species richness.
Species richness is the number of species in a community or defined area.
Define species evenness.
Species evenness is the evenness of abundance, or relative abundance, across the different species in an area.
True or False?
Species richness alone is always a reliable measure of an area's biodiversity.
False.
Species richness does not account for the abundance of each species, so it can be a misleading indicator of diversity.
In the tree-species example, why does Area 1 have higher species diversity than Area 2, despite both having the same species richness?
Area 1 has higher species evenness than Area 2, which is dominated by one species and includes another that is very rare.
Define species diversity.
Species diversity is a measure of a community that is a product of both species richness and species evenness.
Define Simpson's diversity index.
Simpson's diversity index is a mathematical tool that gives a quantitative measure of species diversity, allowing ecosystems to be compared or a single ecosystem to be monitored over time.
What does a higher value of Simpson's diversity index, D, indicate about a community?
A higher value of D indicates greater species richness and evenness.
In the worked river invertebrate example, Site had the higher Simpson's diversity index.
In the worked river invertebrate example, Site A had the higher Simpson's diversity index.
What is the lowest possible value of Simpson's diversity index, D?
The lowest possible value of D is 1.
In Simpson's diversity index formula, what does N represent?
N represents the total number of individuals sampled.
In Simpson's diversity index formula, what does n represent?
n represents the number of individuals of each species.
True or False?
Simpson's diversity index is useful for comparing two very different types of habitat.
False.
Simpson's diversity index is only useful for comparing similar habitats, or the same habitat over time.
What kind of knowledge is needed to develop effective strategies to conserve biodiversity?
Effective conservation strategies need knowledge of biodiversity at both global and regional levels.
How do ecosystems help mitigate climate change?
Ecosystems help mitigate climate change by sequestering carbon dioxide.
Define citizen science.
Citizen science is the involvement of members of the public in collecting data for scientific research, such as counting local wildlife.
What is the Big Butterfly Count?
The Big Butterfly Count is a UK project in which members of the public help count butterfly species.
is the UK government agency that collects data on local species, such as bird populations.
Natural England is the UK government agency that collects data on local species, such as bird populations.
True or False?
The Wildlife Trusts run a long-term hedgehog monitoring programme in the UK.
True.
The Wildlife Trusts, a UK voluntary organisation, run a long-term hedgehog monitoring programme as part of their local biodiversity work.
Define parabiologists.
Parabiologists are local people trained to assist in biological research, bridging local communities and scientific researchers.
In Australia, who are trained to monitor and protect native species using traditional ecological knowledge?
Indigenous rangers are trained to monitor and protect native species using traditional ecological knowledge.
What does the IUCN Red List do?
The IUCN Red List categorises species according to their risk of extinction.
True or False?
The IUCN and the WWF are national agencies that collect regional biodiversity data.
False.
The IUCN and the WWF are international organisations that gather biodiversity data at a global level.
Define habitat restoration.
Habitat restoration is the restoring of degraded ecosystems back to their natural state.
What are the three main categories of biodiversity management strategy?
The three main categories are the creation of protected areas, habitat restoration, and sustainable management practices.
What is an example of a protected-area strategy used to safeguard coral reefs?
The establishment of marine protected areas is used to safeguard coral reefs.
True or False?
Rewilding is an example of a sustainable farming practice.
False.
Rewilding is an example of habitat restoration, reintroducing native species to their original habitats.
Sign up to unlock flashcards
or