4.6 Biodiversity within a Community & 4.7 Investigating Diversity Flashcards
(18 cards)
What is biodiversity?
The variety of living organisms. It can be measured in terms of species diversity (number of species in a community), ecosystem diversity (range of different habitats) and genetic diversity.
Define community
All the different species that live in one area and interact with each other.
What does ‘N’ represent in the index of diversity formula?
Total number of organisms of all species.
What does ‘n’ represent in the index of diversity formula?
Total number of organisms of each species.
What does ‘Σ’ represent in the index of diversity formula?
Sum of.
Impact of farming on species diversity
Decreases species richness; farmland is typically used for only 1 species (monoculture); use of pesticides/herbicides.
Impact of farming on genetic diversity
Decreases; farmers select for certain characteristics, which reduces number of different alleles in the population.
What is one method to increase biodiversity in agriculture?
Use hedgerows instead of fences.
What is a practice that involves growing different crops in the same area?
Growing different crops in the same area or rotating crops after a season.
What should be limited to increase biodiversity in agriculture?
Limit use of pesticides and herbicides.
Measuring genetic diversity (4)
- Frequency of observable characteristics.
- Base sequence of DNA.
- Base sequence of mRNA.
- Amino acid sequence.
What is gene technology?
Sampling DNA or mRNA in order to read and compare the base sequence of organisms.
What can be studied to provide information on an organism’s mRNA and DNA sequences?
The amino acid sequence.
Is simply inferring DNA differences by observing an organism’s characteristics reliable?
No, it is not reliable.
What factors can influence an organism’s characteristics besides genes?
The environment can influence an organism’s characteristics.
Can characteristics be coded for by more than one gene?
Yes, characteristics can be coded for by more than one gene.
Sampling
Selecting a group of individuals to measure that will represent the whole target population.
Random sampling
Create a grid for your sample area, and then randomly generate coordinates where a quadrat or transect can be placed. Repeat until required sample size is reached.
