4.6 + 4.7 Biodiversity Flashcards
What is biodiversity?
The variety of living organisms within a habitat
How can biodiversity be measured?
In terms of species diversity, ecosystem diversity and genetic diversity
What is species diversity?
Number of species in a community
What is ecosystem diversity?
Range of different habitats
Define community.
All the different species that live in one area and interact with each other
How is the index of diversity calculated?
d = N(N-1)/∑n(n-1)
∑ = sum of
N = total number of organisms of all species
n = total number of organisms of each species
What impact does farming have on species diversity? Why?
Decreases species richness
Farmland is typically used for only 1 species (monoculture)
Use of pesticides/herbicides
What impact does farming have on genetic diversity? Why?
Decreases species richness
Farmers select for certain characteristics, which reduces the number of different alleles in the population
How can biodiversity be increased in areas of agriculture?
- Use hedgerows instead of fences
- Grow different crops in the same area or rotate crops around after a season
- Limit use of pesticides and herbicides
Name 4 ways of comparing genetic diversity between organisms.
- Frequency of observable characteristics
- Base sequence of DNA
- Base sequence of mRNA
- Amino acid sequence
What is meant by gene technology?
Sampling DNA or mRNA in order to read and compare the base sequence of organisms
Why is gene technology prefered to observations?
Observing characteristics is not reliable as they could be coded for by more than one gene or influenced by the environment
What is meant by interspecific variation?
Differences between individuals of different species
What is meant by intraspecific variation?
Differences between individuals of the same species
What is sampling?
Selecting a group of individuals measure that represent the whole target population
