Unit 2 - Field Techniques

Question 1

Fieldwork hazards

Answer 1

Hazards relating to field work include terrain, weather conditions, isolation and contact with harmful organisms.

Question 2

Sampling

Answer 2

Gathering data which is representative of the variation within the population being studied.

Question 3

Sampling impact

Answer 3

The effect of the sampling technique on the population being studied.

It is important that sampling does not affect the results obtained, and if it is an invasive technique, then the benefits must outweigh the costs.

Rare species and vulnerable habitats may be protected by legislation, and sampling can only be carried out under license.

Question 4

Point count

Answer 4

Records all individual organisms observed from a stationary location.

Often used to determine abundance of bird populations.

Question 5

Transect

Answer 5

Used to determine changes in a community across an environmental gradient eg. a rocky shore from low to high tide mark.

Can be a line or belt transect, depending on the variability of the community. The higher the variability, the wider the band needed to provide a representative sample.

Question 6

Remote detection

Answer 6

Monitoring is carried out at a distance, using sensors eg. satellites.

Used for global vegetation surveys or to count species in hard to access areas eg. Arctic walruses.

Question 7

Quadrats

Answer 7

Sampling squares for sessile or slow moving organisms eg. plants, limpets.

They ensure that a standard sized area is sampled with equal effort, to minimise bias and increase reliability.

More samples are needed where diversity is higher.

Question 8

Capture techniques

Answer 8

Used to sample mobile species. Birds and bats can be caught in mist nets under license. Moths can be caught with a light trap, small mammals with a Longworth trap.

Animals can be released unharmed.

Question 9

Elusive species

Answer 9

Species which are hard to find and are difficult to sample.

Techniques include camera trapping and scat (droppings) sampling as indirect evidence.

Question 10

Identification

Answer 10

The ability to put a species name to a sample using a classification guide, a biological key or by DNA analysis.

Question 11

Taxonomy

Answer 11

The identification and naming of organisms, and their classification into groups based on shared characteristics.

Question 12

Model organism

Answer 12

The best known species within a taxonomic group. Often the easiest to keep and study, or the most useful or harmful to humans.

Information from the detailed study of a model organism can be applied to the rest of its taxonomic group, as they are closely related.

Question 13

Escherichia coli (E.coli)

Answer 13

Model organism - bacteria.

Used to study basic cell processes and for the development of biotechnology eg. the use of restriction enzymes to modify plasmids.

Question 14

Arabidopsis thaliana

Answer 14

Thale cress. A small, rapidly growing plant belonging to the mustard family.

It was the first plant to have its genome sequenced. Good model for the study of genomics, proteomics and metabolism due to its small genome and few chromosomes.

Question 15

Caenorhabditis elegans (C.elegans)

Answer 15

Belongs to the phylum nematoda.

It was the first multicellular organism to have its genome sequenced. It is used to study developmental biology, apoptosis and meiosis.

Many nematodes are parasitic, so it has potential applications in disease control.

Question 16

Drosophila melanogaster

Answer 16

Fruit fly - model arthropod. Cells have large chromosomes which are easy to study, and the flies are easy to keep and have a short generation time.

Used to study genetics, mutation and evolution

Question 17

Model chordates

Answer 17

Phylum chordata (have a spinal cord).

Model chordates include mice, rats and zebra fish.

Used to study physiology, neurology and toxicology.

Question 18

Phylogenetics

Answer 18

The study of evolutionary history and relationships among individuals or groups of organisms. Heritable traits such as morphology, DNA sequences and protein structure are used to create a phylogenetic tree.

Question 19

Divergent evolution

Answer 19

The development of differing life forms from a common origin, as a result of selection pressure.

Closely related species can have very different phenotypes due to adaptive radiation.

Question 20

Convergent evolution

Answer 20

The separate evolution of similar phenotypic adaptations, which occurs when similar selection pressures act on unrelated lineages. eg. the separate evolution of the eye in humans and octopi.

Question 21

Phylum

Answer 21

Animals are divided into groups called phyla. (Singular = phylum)

Question 22

Chordates

Answer 22

Sea squirts and vertebrates. Possess a notochord (spinal cord).

Question 23

Nematoda

Answer 23

Round worms. very diverse, mainly parasitic. eg. C.elegans

Question 24

Arthropoda

Answer 24

Invertebrates with jointed legs, segmented bodies and paired appendages. eg insects

Question 25

Platyhelminthes

Answer 25

Flatworms with bilateral symmetry, internal organs but no body cavity. Many are parasitic.

Question 26

Mollusca

Answer 26

Diverse phylum, many with shells. eg. slugs and snails.

Question 27

Plant Divisions

Answer 27

The plant kingdom is divided into divisions which include mosses, liverworts, ferns, conifers and flowering plants.

Question 28

Bacteria

Answer 28

The domain bacteria, which lack a true membrane-bound nucleus. (Prokaryotic)

Make up most of the biomass on Earth. Have a key role in nutrient cycling, biotechnology and disease.

Many bacteria have had their genomes sequenced.

Question 29

Archaea

Answer 29

A domain of single celled organisms which have different rRNA and lipid structures to other forms of life.

Many are extremophiles and have unusual metabolic activities eg. methanogenesis

They are prokaryotic

Question 30

Eukaryota

Answer 30

Domain of organisms with a true nucleus and membrane-bound organelles.

Includes all multicellular forms of life and also many single celled organisms.

Includes the plants, animals and fungi.

Question 31

Indicator species

Answer 31

Give information about environmental conditions, such as the presence of a pollutant by their presence, absence or abundance.
eg. lichens indicate levels of sulfur dioxide in the air; freshwater invertebrates such as mayfly nymphs and bloodworms indicate levels of organic pollution.

Question 32

Marking

Answer 32

Used to monitor populations by identifying individual organisms.

Includes banding, tagging, surgical implantation, painting and hair clipping.

Should have a minimal impact on the species being studied and should not affect their chance of survival.

Question 33

Mark and recapture

Answer 33

A method for estimating population size. A sample is captured, marked and released before being recaptured after a certain period of time. The number of marked individuals in the 2nd sample is recorded.

N = (MC)/R

N = the total population; M = the number marked and released; C = the number captured in the 2nd sample; R = the number of re-captures in the 2nd sample (marked)

Question 34

Mark and recapture assumptions

Answer 34

Assume that :
- all have an equal chance of being re-captured
- there is no immigration/emigration
-released individuals can mix freely with the rest of the population

Question 35

Behaviour

Answer 35

An observable response made by an organism to an internal or external stimulus.

Question 36

Reductionist approach

Answer 36

Breaking down complex processes into defined and quantifiable categories.

Question 37

Latency

Answer 37

The interval of time between a stimulus occurring and the response behaviour.

eg. the time interval between the appearance of a female stickleback, and the start of the male’s zig-zag dance.

Question 38

Frequency

Answer 38

The number of times a behaviour occurs within the observation period.

eg. the number of zig-zags in a set time period, in male sticklebacks.

Question 39

Duration

Answer 39

The length of time each behaviour occurs for during the observation period.

eg. how long the zig-zag dance lasts in male sticklebacks.

Question 40

Anthropomorphism

Answer 40

The attribution of human motivation, characteristics or behaviour to non-human animals.

Question 41

Ethogram

Answer 41

A list of species-specific behaviours to be observed and recorded in a study.

Recording the duration of each behaviour and the total time of observation, allows the proportion of time spent on each behaviour to be calculated in a time budget.