Biodiversity Flashcards
How can mutations affect biodiversity?
- occur in DNA and creates newallele
Interbreeding
- individuals from two populations breed and transfer alleles
- causes gene flow
Selective breeding
- few individuals in population selected for their advantageous characteristics and bred
How does natural selection affect biodiversity
- species evolve to code for characteristics that code for advantageous characteristics
- less advantageous genes will be lost overtime
Factors that affect genetic biodiversity (7)
- Mutations in DNA
- Interbreeding; gene flow
- selective breeding
I - artifices cloning
- natural selection
- founder effect
- genetic drift
Importance of biodiversity
- Maintains balanced ecosystem as all species are dependant
Human activity that affects biodiversity (3)
- Deforestation
- Agriculture: increases monoculture
- Clearing land for housing
- Climate change; human activity increases global warming
Sampling and its uses (3)
- Taking measurements of a limited number of individual organisms present in a particular area
- measures particular characteristics and abundance of species
- helps make predictions or generalisations
Random sampling
- Selecting individuals by chance, each individual in the population has an equal chance of being selected
Non-random sampling
- Opportunistic; organisms conveniently available
- Systematic; sampling different areas within an overall habitat. Measures change over an area eg transect
What can affect reliability of a sample
- Sampling bias
- Chance; organism might not be representative
Different sampling techniques for animals
- Pooter: small insects
- Sweeter nets: organisms in long nets
- Pitfall traps: small invertebrates and mammals
- Tree beating
- Kick sampling: river bank and bed
Sampling for animals
- Quadrat; frame or point
Species evenness (2)
- Number of individual species on a given area
- How close the number of species are
Why are abiotic sensors used? (4)
- Human errors
- greater precision
- data can be stored and tracked on computer
- rapid changes can be detected
What are abiotic factors; included examples(6)
- Nonliving conditions in an environment. Usually have direct affect on organisms in habitat.
- eg; pH, wind speed, light intensity, relative humidity, temperature
How is biodiversity calculated
- Simpson’s index; takes into account richness and evenness with 1 being the highest diversity
Habitat features for low biodiversity (5)
- few numbers of successful species
- stress/ extreme with few ecological niches
- simple food webs
- very specific adaptations
- change to the environment massively affects ecosystem
Importance of generic biodiversity
- The more alleles present in a population, the more biodiversity
- Species with greater genetic biodiversity are more likely to be able to adapt to environment
- It is more likely for organisms to contain advantageous characteristics
Polymorphism (2)
- Genes that have more than one allele
- eg blood type in humans are determined by 3 alleles
How does deforestation affect biodiversity (3)
- Reduces number of trees
- destroys animal habitat so reduces animal species present in that area
- animals forced to migrate to other areas which increases neighbouring biodiversity
How does agriculture affect biodiversity
- Pesticides reduces biodiversity
- herbicides also reduces biodiversity
- Monoculture
Reasons for maintaining biodiversity
- Aesthetics; how the region appears
- Economical; how the region can affect income
- Ecological reasons; how species are supported in the region
Economic reasons for maintaining biodiversity (7)
- Soil erosion and desertification due to deforestation causes lack of crops and decline in resources
- By not conserving organisms used to make things, the removal of resources makes economical industries viable
- Species with potentially economical importance can become extinct through large scale habitat loss
- Monoculture; soil depletion makes soil weaker and plants more susceptible to pests
- Lack of biodiversity makes organisms more vulnerable against abiotic stresses eg disease/ weather
- Promotes tourism with pleasing biodiversity
- Plant biodiversity means advantageous characteristics can be interbred