Biodiversity Flashcards
What is biodiversity?
The range and variety of genes, species and habitats in a particular region
(Species diversity, genetic diversity and ecosystem diversity)
What is species diversity?
The number of different species and individuals within each species in a community
What is genetic diversity?
The variety of genes amongst all the individuals in a population of one species
What is ecosystem diversity?
The range of different habitats
What’s a hybrid?
A sterile offspring produced by the mating of two different species (offspring infertile)
eg. Zonkey, liger, mule, wholphin
What is species richness?
The number of different species in a given area at a time
What is specie evenness?
The number of organisms of each species in a given area at a given time
How do you calculate the index of diversity?
d = N(N - 1) / the sum of n(n - 1)
N = total number of organisms of all species
n = total number of organisms of each species
What impact does agriculture have on species diversity?
Continuous pop growth leads to pressure on food production :
Reduces species richness and diversity
- farmland typically generates a monoculture
- use of pesticides and herbicides
What impact does farming have on genetic diversity?
Farming reduces genetic diversity
- Select species with specific qualities/characteristics which reduces alleles in the population
How is creating a monoculture a problem for biodiversity?
Replacing natural meadows with a single species of crop reduce species richness
Boosts profit for the farmer as they only need nutrients for one species
What are the solutions for greater biodiversity once a monoculture has been created?
Cut verge/field edges after flowering
Create natural meadows and use hay not grass for silage
Plant native trees on land with low species diversity
What’s a solution to overgrazing of land to help increase biodiversity ?
Rotation with a field left fallow
What’s a solution for removal of hedgerows (and replace,ent with fences as field boundaries)?
Maintain existing hedgerows in A shape
Plant hedges rather than erect fences
What are the advantages of planting hedgerows?
Increase biodiversity so increase predators
Increase predators = more yield and less damage to crops
Increase pollinators increases yield and income
Attract tourists/subsidiaries (income for diversification)
What are the disadvantages of planting hedgerows?
Reduced land area for crop growth
Increased biodiversity of pest population reduces yield
Increase interspecific competition lowers income
More difficult to farm
What can pesticide and inorganic fertiliser use lead to?
Eutrophication
What is eutrophication?
Fertiliser runs off into bodies of water where it dissolves and gives plants nutrients (leads to algal bloom) preventing sunlight reaching other plants and aerobic decomposition of algae suffocates the fish by using the oxygen
How do you reduce/stop eutrophication?
Limit fertiliser use near bodies of water
Use organic fertilisers (manure)
How can we solve the problem of fertiliser and pesticide use reducing biodiversity?
Reduce pesticide use by using biological control
Use organic rather than inorganic fertiliser
Use crop rotation
Use intercropping
Introduce conservation headland
What is crop rotation?
Different species of crops are grown in different fields and alternated to supply different nutrients to the soil (nitrogen fixing crop)
What is intercropping?
Used instead of herbicides to control weeds - where 2 or more crops are grown in close proximity
What is a conservation headland?
An area at field edges where pesticides aren’t used so wild flowers/insects can breed
What is a solution for filling in ponds and draining marshes/wetland?
Maintain existing ponds and where possible create new ones
Leave wet corners of fields rather than draining them
Name 4 ways we can measure genetic diversity?
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 nd compare base sequences or organisms
Alternatively the amino acid sequence can be studied which will also provide information on DNA and mRNA sequences of the organisms
Why is gene technology better than observation?
Simply inferring DNA differences by observing an organism characteristics is not reliable, the characteristics could be coded for by more than one gene/influenced by the environment
What is interspecific and intraspecific variation?
INTERspecific - difference between individuals of different organisms
INTRAspecific - difference between individuals of the same species
How do you randomly sample an area to calculate biodiversity?
Use a random number generator to create a coordinate to place the quadrat
Why is a large random sample used when calculating biodiversity.
It removes the sampling bias
The number of samples improves how representative of the population the results are
