Biodiversity Flashcards
Describe the meaning of species diversity
The number of different species and the number of individuals of each species within a community.
Classification
organisation of living organisms into groups
What do members of a single species have in common
They are capable of breeding to produce living, fertile offspring.
Binominal system
Universal system where organisms are identified by two names
-generic name (Genus)
-specific name (species)
Courtship behaviours
Members of the same species can identify each other through physical and biochemical features and behaviour
How do courtship behaviours enable successful breeding
-Enable individuals to recognise members of their own species
-Identify a mate that is capable of breeding
-Form a pair bond
-Synchronise mating
-become able to breed
Artifical classification
Divides organisms according to differences that are useful at the time. (colour, size, number of legs).
These are known as analogous characteristics where they have the same function but do not have the same evolutionary origin
Phylogenetic classification
Based upon the evolutionary relationships between organisms and their ancestors
-classifies species into groups using shared characteristics derived from their ancestors
Generic name
denotes the genus to which the organisms belong
Specific name
Denotes the species to which the organism belongs
What are relationships in phylogenetic classification based on
Homologous characteristics-similar evolutionary origins regardless of their function
Why do we use a binomial name in
Latin
If we use common names it doesn’t tell
us very much about a species.
The binomial name tells us the Genus
and the Species of an organism and it’s
called in the same way EVERYWHERE
in the world
It allows us to see what it is closely
related to
what is meant by a hierarchy
Smaller groups within larger groups, and no overlap between groups
Taxonomy
study of taxons and their position in a hierarchical order
What does the genus of organisms show
Close relationship
Why do different species look similar
-Live in similar environments
-have similar selection pressures
-Similar alleles will have the selective advantage
-Produces similar/same proteins and therefore have similar characteristics
An example of a hierarchy
Classification systems
What is the order of taxonomic ranks
Domain, kingdom, phylum, class, order, family, genus, species
What are examples of courtships behaviour
displays, signals, gift bringing, calls
How are phylogenetic relationships displayed
A tree-like diagram
-the oldest species is at the base of the tree while the most recent ones are represented by the ends of the branches
Explain the relationship between classification and evolution
Phylogenetic classification is based on characteristics which have the same evolutionary origins. Taxa are based on evolutionary line of descent.
What is the highest taxonomic rank
Domain
What are the three recognised Domain
bacteria, Archaea and eukarya
Biodiversity
the general term used to describe the variety in the living world
Genetic diversity
the variety of genes possessed by the individuals that make up a population of a species
Ecosystem diversity
the range of different habitats, from a small local habitat to the whole earth
Species richness
The number of different species in a particular area at a given time
community
all the living organisms present in an ecosystem at a given time
Index of diversity
A measure of species diversity. It is a calculation to measure the relationship between the number of species in a community and the number of individuals in each species
What is the impact of agriculture on species diversity
-Farmers select species with desirable qualities which means there is less space for other species as they have to compete for what little space and resources they have. This leads to reduced species diversity.
What practices have led to the removal of habitats and reduced species diversity
-Removal of hedgerows
-Creating monocultures
-filling in ponds and draining marshes
-Over-grazing of land
What management techniques can be used to increase species diversity
-maintain existing hedgerows
-plant hedges rather than fences
-maintain existing ponds
-leave wet corners of fields
-reduce the use of pesticides
-use organic fertilisers
What are the 4 ways to investigate biodiversity
-Comparison of observable characteristics
-Comparison of DNA base sequences
-Comparison of the base sequence of mRNA
-comparison of amino acid sequences in proteins
How is the comparison of observable characteristics used to investigate biodiversity
genetic diversity is measured by observing the characteristics of organisms and is based on the fact that each characteristic is determined by a gene which depends on the number of alleles
What are the limitations of comparison of observable characteristics
-large number of characteristics are polygenic
-characteristics can be changed by the environment
How is the comparison of DNA base sequences used to investigate biodiversity
In computerised systems each nucleotide base can be tagged with a different colour fluorescent dye which produces a series of coloured bands in a pattern which can be analysed and compared with another species to determine how diverse they are
How can we determine how closely related species are based on their DNA sequence
Due to mutations the sequences of nucleotide bases in the DNA of the new species will change. Over time the new species will accumulate more and more differences in the DNA.
How is the comparison of the base sequence of mRNA used to compare genetic diversity
mRNA is coded for by DNA. base sequence of mRNA is complementary to those of the strands of DNA from which they are made
How is the comparison of amino acid sequence in proteins
the sequence of amino acids in proteins is determined by mRNA which in turn is determined by DNA. The degree of similarity in the amino acid sequence of the same protein in two species will also reflect how closely related the two species are.
Interspecific variation
When one species differs from another
Intraspecific variation
When members of the same species also differ from each other
Why might measurements not be representative
-Sampling bias
-chance
What is sampling
Taking measurements of individuals, selected from the population of organisms which is being investigated
How can an investigator carry out random sampling
- divide the study area into a grid of numbered lines
- using random numbers from a generator obtain a series of coordinates
- take samples at the intersection of each pair of coordinates
How can we minimise chance affecting the sample
-use a large sample size
-statistical tests
