Unit 2- Field techniques Flashcards
How must sampling of wild organisms be carried out?
In a manner that minimises impact on wild species and habitats. Consideration must be given to rare and vulnerable species and habitats, which are protected by legislation.
Explain the 3 types of sampling
1) Randomised- the advantage to this is that there is no bias however this can result in all sample sites being very close together by chance which could lead to over or under representation.
2) Systematic- which is when samples are taken at equal divisions.
3) Stratified- this is when you look at the ecosystem within different strata/layers, this is done when you know there are distinct groups eg. Insects in a forest and insects in a grassland.
What is used to measure the abundance of sessile organisms.
A quadrat
Give an example of capture techniques used for mobile animals
Pitfall traps, kick sampling, flight intercept nets, malaise traps (large tent like traps for flying insects). Small mammal traps such as Longworth traps are used to catch organisms such as mice.
What can be used to sample more elusive species?
Camera traps or scat sampling
How can an organism/sample be identified?
Classification guides, biological keys or analysis of DNA or protein.
What is divergent and convergent evolution?
Divergent evolution is the accumulation of differences as species from a common ancestor undergo changes over time. Convergent evolution is when organisms appear to have similar structures but have actually evolved from different ancestories eg. Wings in bats and birds.
What are the 3 domains of life?
Bacteria, Archaea and Eukarya
What is the Eukaryote domain classed into?
The plant and animal kingdom
What are the major divisions of the plant kingdom?
Liverworts- Non-vascular, produce spores and no stomata.
Mosses- Non-vascular produce spores and have stomata.
Ferns- Vascular, no flowers or seeds and spore producing.
Gymnosperms- these are conifers that produce cones.
Angiosperms- flowering plants.
What are the phylum of the animal kingdom?
There are about 40 Phyla but the majority of animals can be classed into these 6
Chordata- sea squirts and vertebrates
Arthropoda- joint-legged invertebrates: segmented body typically with paired appendages
Nematoda- round worms: very diverse, many parasitic
Platyhelminthes- flatworms: bilateral symmetry, internal organs but no body cavity, many parasitic
Mollusca- molluscs: diverse, many with shells.
Annelida- Segmented worms
What are phyla further divided into?
Class, order, family, genus until the species is named.
What is a model organism and give an example?
Model organisms are used to obtain information that can be applied to species that are more difficult to study directly. Examples include the bacterium E. coli; the flowering plant Arabidopsis thaliana; the nematode C. elegans; the arthropod Drosophila melanogaster and mice, rats and zebrafish which are all chordates.
What do indicator species do?
Give information of environmental qualities, such as presence of pollutant.
What is mark and recapture used for?
Mark and recapture is a method for estimating population size. A sample of the population is captured and marked (M) and released. After an interval of time, a second sample is captured (C). If some of the individuals in this second sample are recaptured (R) then the total population N = (MC)/R, assuming that all individuals have an equal chance of capture and that there is no immigration or emigration.
