Topic 4 - Biodiversity Flashcards
(36 cards)
What is biodiversity?
The variety of living organisms in a particular area.
What is species diversity?
The number of different species and the number of individuals within each species in a community.
What is genetic diversity?
The variety of genetic information within a species, reflecting the number of different alleles in the gene pool.
What is ecosystem diversity?
The range of different habitats within a particular area or ecosystem.
What is three things affect biodiversity?
Deforestation
Agricultural practices
Urbanisation
How can species richness be measured?
Random sampling:
- divide the area into a grid or use a transect
- use a quadrant or sampling frame to randomly sample different locations
- record the species found within each sample
What are the factors affecting species richness?
- Habitat size
- Environmental stability
- Human activity
- Invasive species
What is the index of diversity?
A measure of bio diversity that considers both species richness and the relative abundance of individuals within each species in a community.
What is the formula for index of diversity?
D = index of diversity
N = total number of organisms of all species
n = total number of organisms of each individual species
E = sum of
How do you calculate the index of diversity step-by-step?
- Count the total number of organisms in the community (N).
- Count the total number of individuals for each species (n).
- Substitute the values into the formula and calculate E n(n-1) for all species.
- Applied to the formula..
What does a high index of diversity value indicate?
High bod diversity meaning a large number of species and balanced population sizes.
What does low index of diversity value mean?
Indicates low bod diversity, meaning few species or dominance of one species.
What are four factors affecting the index of diversity?
- Habitat destruction: reduces the number of species and disrupt ecosystem balance.
- Pollution: effect sensitive species reducing their populations.
- Deforestation: removes habitats, decreasing species richness and abundance..
- Agriculture: monoculture reduces habitat variety and species diversity.
What is the impact of agriculture on biodiversity?
- Agricultural ecosystems often reduced by diversity as human select specific species or traits leading to fewer species and reduced genetic diversity.
- Monoculture farming limits the number of habitats available reducing the survival of other species.
- Farmland practices often replace natural ecosystems with lower species richness and affect ecosystems stability.
What are six techniques to maintain biodiversity in farming?
- Hedge rose: use Hydro instead of fences to provide habitats in corridors for wildlife.
- : grow different crops in the same area to increase species variety and reduce soil degradation.
- Reduced herbicide and pesticides: minimise chemicals to prevent harm to non-targeted organisms and allow natural predators to thrive.
- Preserving wetlands: avoid draining wetlands as they serve as critical habitats for diverse species.
- Buffer zones: leave uncultivated areas near water bodies to protect aquatic ecosystems.
- Rotation: rotate crops annually to maintain fertility and prevent the dominance of pests specific to one crop type.
How can you balance farming and conservation?
- sustainable farming practices aim to maximise yield whilst protecting ecosystems.
- government schemes and subsidies can encourage farmers to adopt biodiversity friendly methods.
- conservation efforts help maintain ecosystem services such as pollination water regulation and solid fertility which are essential for agriculture.
What is genetic diversity?
The variety of alleles within or between species.
How can genetic diversity be determined?
- Comparing the frequency of measurable or observable characteristics.
- Analysing the base sequence of DNA.
- Analysing the base of mRNA.
- Comparing the amino acid sequences of proteins and coded by DNA and mRNA.
What are the limitations with measuring genetic diversity with observable characteristics?
Polygenic inheritance: many characteristics are controlled by more than one gene making comparisons complex.
Convergent evolution: similar characteristics may evolve independently in unrelated species leading to false classifications.
Environmental influence: characteristics influence by environmental factors may not accurately reflect genetic influences.
What is meant DNA base sequence comparison on genetic diversity?
Comparing DNA sequences provides direct insight into genetic differences. Modern techniques such as DNA sequences allows for precise comparison.
What is mRNA base sequence comparisons in genetic diversity?
Reflect the genes that are actively transcribed offering another layer of genetic information.
Why is comp amino acid sequences useful in determining genetic diversity?
Proteins encoded by genes can be compared to reveal evolution revel relationships.
What are the advantages of molecular techniques in investigating genetic diversity?
- accuracy: molecular method are more reliable than observable characteristics as they are directly reflective of genetic information.
- Quantitative data: based on amino acid sequence allows for numerical comparison, improving objectivity.
- Evolutionary insights: helps construct genetic trees to show evolutionary relationships.
What are quantitive investigations?
Allow scientists to measure and compare variation within and between species. These studies rely on numerical data and statistical analysis to draw conclusions.
