Biodiversity Flashcards
What is meant by the term ‘species diversity’?
refers to the number of different species and the number of individuals within a species, in a community
What is meant by the term ‘genetic diversity’?
refers to the variety of genes possessed by individuals that make up the population of a species
What is meant by the term ‘ecosystem diversity’?
refers to the range of different habitats
What is meant by the term ‘species richness’?
the number of different species in a particular area at a given time
Why is it more useful to calculate species diversity, rather than relying on species richness?
It measures number of species AND the number of individuals. Some species may only be present in small numbers
What is meant by the term ‘biodiversity’?
the range and variety of genes, species and habitats within a specific region
How does the diversity of agricultural land differ from that of a natural ecosystem?
- agricultural land is controlled by humans.
- There is a smaller number of species and a smaller variety of alleles.
- Large amounts of species considered valuable reduce the space and nutrients available for other species
Give 3 farming practices that directly reduce species diversity
- removal of hedgerows
- creating of mono-cultures
- filling in ponds/draining other wetlands
- over-grazing of land –> preventing regeneration of woodland
Give 3 farming practices that indirectly reduce species diversity
- use of pesticides/inorganic fertilisers
- escape of effluent from silage stores
- absence of crop rotation and lack of inter-cropping
Give 5 examples of conservation techniques to reduce the impacts of farming practices
- plant hedges as field boundaries
- reduce pesticide use/ use organic fertilisers
- use inter-cropping to control weeds
- maintain existing ponds
- leave wet corners of fields
What are 4 ways of investigating genetic/bio diversity?
- comparing observable characteristics
- comparing DNA base sequence
- comparing mRNA base sequence
- comparing a/a sequence in proteins
Give 3 limitations of comparing observable characteristics as a way of measuring diversity
- large numbers of observable characteristics are coded for by more than one gene
- difficult to distinguish
- ## Characteristics can be modified by the environment
What is interspecific variation?
differences in organisms from two different species
What is intraspecific variation?
members of the same species differ from one another
