2.1 redone Flashcards
Sampling types
Randomised
Stratified
Systematic
Systematic sampling
Where a sampler will choose the most suitable location to carry out sampling
Randomised sampling
Where the location for sampling is chosen using a method which means that one sample site has an equal probability of being chosen, compared to any other
Stratified sampling
Where a sampler will identify and estimate the size of different areas of the habitat. These areas will be separately sampled based on how much of the habitat they take up.
Advantage of stratified sampling
A more accurate sample of the whole area will be achieved
Disadvantage of stratified sampling
Estimating the size of different areas in the habitat is a source of error
Systematic sampling disadvantage
Can be seen a a biased method of sampling
Advantage of systematic sampling
Will provide the most relevant results for the investigation
Advantage of randomised sampling
There is no biased involved in the sampling
Disadvantage of randomised sampling
The samples may not be representative of the whole habitat, if too few samples are taken.
Accuracy
Where the result is close to the true value.
Precision
Where results are consistent.
Taxonomy
How different organisms are split up based on different characteristics
Phylogenetics
The study of evolutionary relationships and history using fossilised evidence and DNA sequence data
Classic taxonomy
Based on morphology
What does phylogenetics use
DNA sequence data
Protein structures
Morphology
Fossil evidence
Phylogenetic tree
A graph which assumes mutations occur at a constant rate and is used to predict when evolutionary lines diverged.
Inaccuracy of phylogenetic trees
They assume mutations occur at constant rate, however mutations are random and spontaneous
Divergent evolution
Where two species with the same common ancestors evolve to have different structures, due to the species occupying different niches or environments.
Convergent evolution
Where two species which have different ancestors evolve to have similar structures, due to the species occupying similar niches or similar environments.
Taxonomic groups
Nematodes - parasitic worms
Chordates - animals with spines
Arthropods - insects and invertebrates
Model organisms
A species which has been studied extensively and can be used to predict the characteristics of other species.
Bacteria model organism
E. Coli
Plant model organism
Arabidopsis Thaliana
Nematode model organism
C. Elegans
Mammal model organism
Chordata
Arthropod model organism
Drosophila melanogaster
Indicator species
A species which can inform biologists of environmental conditions and pollution level by its presence or absence.
Susceptible species
A species which has a reduced or absent population due to unfavourable environmental factors
Indicator species examples
Lichen and crayfish
Favoured species
A species which has a high population due to beneficial environmental conditions.
Population count formula
N = MC/R
M is captured and marked
C is total recaptured
R is recapture number
Procedure for population estimate
Carry out capture and mark
Release
Carry out second capture
Controlled variables in population estimate
Equal probability of finding marked or non marked individual on second capture
No immigration of emigration
Behaviour definition
The observable response an organism makes to an external stimulus
Difficulties of studying behaviour
It’s a complex adaptation individual to many species
It has many uncontrollable variables.
Different between events and states
Events are brief and states are over long durations of time
Ethogram
A detailed list of an organisms behaviours
Samples for behaviours
Focal - one individual, note everything
Occurrence - when and how many times a behaviour occurs
Scan - note what all members are doing at specific time intervals
Qualitative data
Data based on human evaluation
Quantitive data
Data based on numerical results
Anthropomorphism
Giving animals human characteristics, behaviours and emotion.
This is poor practice since other animals do not behave like humans.
