Biodviersity Flashcards
What does Biodiversity mean
A measure of variation found in the living world
What is a habitat
Where an organism lives
What is the definition of a species
A group of organisms that can interbreed to produce fertile offspring
What levels are biodiversity considered at and explain what they mean
Habitat - The range of different habitats in an ecosystem
Species - Related to species richness and species evenness
Genetic - Variation within a species. For example the number of different alleles within the population
Why do we take samples to measure biodiversity
It can be time consuming to measure the whole area so usually smaller samples are taken then scaled up so they are representative of the population
What is species richness and evenness
Richness - the number of species in an area
Eveness - the proportion/abundance of each species in an area
What are the types of sampling
Random - randomly generating coordinates
Non random - opportunistic - Taking samples based on previous knowledge. This is much
easier and quicker but data will likely be biased
systematic - Taking samples usually when land isn’t evenly distributes line or
belt transect can be used. Species may be missed leading to an
underestimate of biodiversity
stratified - dividing a habitat into areas that appear different. This ensures
areas aren’t underrepresented
How can you improve your sampling techniques and what techniques can be used to sample
Use a key
Take repeats at different times of the year
Take percentage cover
Calculate mean density
use Abundant
Common
Frequent
Occasional
RareHow can you sample larger animals
Sweep nets - For insects in long grass or winged insects such as butterflies
Pooters - Suck insects up, usually from a bark of a tree
Tullgren funnel - A light drives animals down as litter dries out
Pitfall trap - Trap to catch small animals
Capture recapture technique (c1*c2)/marked individuals on c2
What is an Allele Locus Polymorphic gene locus Simpsons index
Version of a gene
Position of that gene on a chromosome
A locus that has more than two alleles
A measure of the diversity of a habitat
What is the formula for Simpsons Index
𝐷 = 1 - Ʃ (n/N)^2
What does a high and a low Simpsons index mean
There is high biodiversity, complex food webs many niches habitat is more likely to survive if there was a change in environment
There is a low biodiversity, simple food webs , more specific adaptation. The habitat is dominated by one of two species and would less likely be able to adapt and survive if there was a change in the environment
How can we calculate genetic diversity
You can look at the proportion of polymorphic loci compared to the total loci
How has human population growth affected biodiversity
Human population is growing exponentially so there’s more demand for houses and food. This has led to destruction of habitats , deforestation, pollution of the atmosphere. We alter ecosystems to provide ourselves with food
How has agriculture and selective breeding affected biodiversity
We clear natural vegetation reducing habitat size and genetic diversity. Modern agriculture relies upon monoculture and selective breeding to increase efficiency. This limits genetic diversity. With the same crops being grown soil erosion arises and lack of nutrients also appear. This is because the same minerals are always taken and organic matter is not replaced
Farmers pick particular traits when breeding this leads to loss of alleles that could be important in the future. Lack of genetic diversity leaves animals susceptible to diseases and extinction of species
How has climate change affected biodiversity
As the earths temperature increases this leads to migration of animals to poles and they may carry diseases with them which could affect species diversity. Habitats are also lost as ice starts to melt which could see polar bears become extinct. Little variation of crops will see them struggle to survive and will be vulnerable to disease
What are the main factors in maintaining biodiversity
Economical
Ecological
Aesthetics
What are the ecological reasons to maintain biodiversity
Interdependence of organisms- One species affected may effect the rest of the species in the habitat
Keystone species are influential
For example wolves at the Yellowstone national park ate the deer’s completely changing the nature of the ecosystem allowed other species to thrives
Another example beavers build dams that creates still water for other species to live
What are the economical reasons to maintain biodiversity
Ecosystem services - atmosphere cleaning
soil fomration
pollination
oxygen
fresh clean water
plants are sources of medicine
What are the aesthetic reasons to maintain biodiversity
Improves your mental health, you get a feeling of joy, act as a form of inspiration
What are the two types of conservation
Ex situ
In situ
What is conservation
Allow endangered species to survive and make sure there’s a sustainable use of genetic resources for the future. Active management takes place to ensure biodiversity is maintained
What are examples of In situ and give + and -
Wildlife reserves
Marine conservation zones
+ Ecological integrity is maintained
+ Permanently protects biodiversity
+ Conserved in natural environment
- Population may have already lost much of its genetic diversity
- Not protected from poachers
- Conditions that caused disruption may still be present
What are examples of Ex situ and give + and -
Conservation outside normal habitat of the species
Seed banks
Botanical gardens
Zoos
Captive breeding programmes
+ Organisms are protected from predation and poaching
+ Selective breeding to increase genetic diversity
+ Conservation can be used for education
- Hard to encourage breeding outside of natural habitat
- May not be welcomed back to environment, difficulties of acceptance
- Exhibit different behaviours
- Expensive to maintain favourable conditions
- Likely to have limited genetic diversity
Why are seed banks and botanic gardens advantageous
Seed banks - Contain seeds that are viable for decades, can be used for repopulation . Require low maintenance costs, easy to transport and lots of storage
Botanic gardens - Plants can breed asexually
- Can be repopulated
- can be stored and germinated for future needs
What are the conservation agreements made
CITES (Convention on International Trade in Endangered Species)
Aim to regulate trade of extinct animals across borders
RCBD (Rio Convention on Biological Diversity)
Sustainable use of genetic resources
Conservation of biological diversity
CSS (Countryside Stewardship Scheme)
Improving the beauty of countryside
Putting in footpaths for public access
How would you use a transect
Stretch a long piece of rope across a habitat and take samples along a line.
A line transect may not be representative of population though it is quick and easy
A belt transect will be more representative it can be continuous (quadrats back to back) or interrupted (quadrats at regular intervals)
What are factors that increase genetic diversity
Mutations - new allele created
Interbreeding between different populations - transfer of alleles (gene flow)
What are factors that decrease genetic diversity
Selective breeding - selecting desirable characteristics
Captive breeding programmes - usually as members in the wild are extinct or endangered
Artificial cloning
Natural selection
Genetic bottlenecks
Genetic drift
Founder effect
What are genetic bottlenecks
Few species survive an event or change which reduces the gene pool
What is natural selection
Species evolve over time to contain alleles that code for advantageous characteristics so alleles for less advantageous characteristics are lost
What is the founder effect
Small number of individuals form a new colony altering the genetic frequency and are geographically isolated.
Small gene pool
What is genetic drift
Random how alleles are passed on so frequency of an occurrence of an allele will vary and some alleles may disappear from the population completely
Why can seed banks be a negative
Some seeds die when dried and frozen
