biodiversity Flashcards
what is classification
organising living organisms into groups
what does it allow us to study
evolutionary relationships and the genetics of different species
what are phylogenetic classifiation system
attempts to arrange species into groups based on their evoluntionary origins and relationships.
what is speciation
the formation of a new and distinct species from common ancestors in evolution
what is taxonomy
the study of these classification groups and their postitions in a hiercarchal order , known as taxonomic ranks
what is the taxonomy names
domain , kingdom , phylum , class , order , family , genus ,species
what is a feature of taxonomy
each organism can only belong to one group at each level - no overlap of the groups .
what is the highest rank
a domain is the highest taxonomic rank and species smallest
what is the binomial system
bi -two nomial - name
two name system of things which is their genus , species
what is a species definition
a group of similar organisms that have the same features / same genes that are able to reproduce to give fertile offspring
what is a species
the group that contains only one type of organism
what is courtship
courtship in animals is a behaviour that eventually results in mating and reproduction
what is the definition for biodiversity
the general term to describe the variety of living organisms in a particular area
what are the 3 components of biodiversity
- species diversity - the number of different species and number of individuals of each species within one community
-genetic diversity - the variety of genes possessed by individuals that make up any one species
-ecosystem diversity - the range of different habitats within a particular area
how do we measure species richness
we measure species diversity at a given time and this can be investigated using sampling within the habitat
what is the index of diversity
is a measure of species diversity which takes into account both richness ( abundance ) and eveness. the index of diversity will give you a positive number equal to or bigger than 1
- if the index is 1 then all the organisms are the same ( no diversity )
- the bigger the index of diversity , the more diverse an area is
how do you calulate index of diversity
N(N-1)
______
En(n-1)
N = total number of organisms in an area of all species
n= the total number of organisms of a particular species in the area
what is a community
populations of different species living in the same habitat at the same time
what is an ecosystem
a community and their abiotic enviroment
what is a habitat
the place where an organism lives
what is a population
all the organisms of one species in a habitat
why is growing population a problem
- more land is being used for building houses, shops ect and this destroys habitats of plants and animals
- higher demand for food - compromises food security, and leads to greater land lost for farming .
-more waste and pollution produced which damages the enviroment - from agriculture, transport , household waste ect
-finite resources are being used up eg fossil fuels and metal ores
what farming practices have reduced habitats and species diversity
- removal of hedgerows and woodlands
-creating a monoculture
-filling in ponds , marshes and draining peat bogs
-use of pesticides and fertilisers - escape of sewage
- absence of crop rotation
why has productivity of farming increased
need to produce more food at a quicker rate , in other words farmers needed to produce a higher yield as population is expanding
what are the management techniques
- use organic rather rather than inorganic fertilisers
-reduce the use of pestidicdes - use genetically modified organisms resistant to pests - plant hedges rather than erect fences as field boundaries
-maintain existing ponds and where possible create new ones
-maintain existing hedgerows at the most beneficial height and shape
-plant native trees on land with a low species diversity rather than in rich -species areas
How do hedgerows around fields increase biodiversity
Increases plant and animal species diversity , more variety of food sources ,
What is intercropping
Growing different crops in the same area
How do scientists look at evolutionary relationships
-this includes changes to visible internal and external features
-DNA and proteins
-comparisons can be made of , DNA base sequence , mRNA base sequence, amino acid sequence
How is comparison of observable characteristics carried out
Advances in gene technology , see what alleles organisms have based on the fact each characteristic is determined by a gene or genes , the variety within an observable characteristic depends on the number and variety of alleles of that gene
What are the limitations of this
Characteristics can also be caused by environmental factors and a large number of observable characteristics are coded for by more than one gene
How do we compare the base sequences of mRNA
This is coded for by dna so base sequences are complementary to those of the strand on dna so we can measure genetic diversity from dna diversity
How can we compare amino acid sequence
Determined by dna so we can compare AA sequence of proteins , the degree of similarity in the AA sequence of the same protein in two species will also reflect how closely related they are . This can be done by counting similarities or differences
How is comparison of dna base sequecnes carried out
Technology means we can read base sequences of dna and compare patterns of coloured bands (done by lasers and computer software) which shows the nucleotide bases present and therefore how diverse they are
How do we use dna base sequence evidence
Due to mutations the sequences of nucleotide bases in dna will change, so species more closely related will show more similarity In their dna base sequence
Why might sampling not be representative
Chance
Sampling bias
How can sampling bias be prevented
-use a random number generator , random sampling , analysis of data collected
How can we minimise the effect of chance
Use a large sample size , smaller probability that chance will influence
How can statistical tests be used to analyse the data collected
Shows us the probability of obtaining the values we got by chance and whether it is representative
Explain the importance of taking large samples of plants
Makes sure sample was representative and identity anomalies
Explain the importance of taking samples at random
Removes bias
The index of diversity was higher in the hedge than in the barley field suggest why
Hedge has more plant species , larger variety of food sources and therefore more habitats
What are some courtship examples ( might be Asked
- colourful patterns and visual displays such as the male pecok tail
-complex courtship behaviours - chemical signals called pheromones
In recent years our knowledge of prokaryotic biodiversity in the soil has increased suggest why
-dna / genome sequencing now used
-can analyse more / every prokaryotic species in the community
-rather than just recording measurable/observable characteristics
