Terms Flashcards
(234 cards)
1
Q
Hypothesis
A
Prediction of a relationship between independent and dependent variables.
2
Q
Null hypothesis
A
Easy to test prediction that there is no relationship between the independent and dependent variable.
3
Q
Peer review
A
Appraisal of a piece of work or a specific report by an independent expert in the relevant field.
4
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Plagiarism
A
Copying the work of others without acknowledgment.
5
Q
Reduction
A
Lowering the numbers of an organism used in a study in order to minimise harm to species.
6
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Refinement
A
The consideration and adoption of methods to minimise harm to a species, including improved animal accommodation and veterinary provision.
7
Q
Replacement
A
Use of an alternative to whole organisms in a study to minimise harm to a species.
8
Q
Replication
A
Repeating an experiment either within the study or independently to improve reliability.
9
Q
Review article
A
Expert report that summarises all that is known about an area of interest.
10
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Accuracy
A
The degree of closeness to the true, actual value of measurement.
11
Q
Causation
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A link between variables in which one variable is known to be directly affecting the other.
12
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Confounding variables
A
Factors that influence the results of an experiment and cause mistaken associations between the independent and dependent variable to be made.
13
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Continuous variable
A
Variable that can be measured and from which infinite values exist.
14
Q
Correlation
A
A relationship between two variables that does not imply causation.
15
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Dependant variable
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Factor that is measured to obtain experimental data.
16
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Discrete variable
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Variable that must fall into clear-cut variables.
17
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In vitro
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Experimental procedure carried out in laboratory conditions using parts of organisms such as cells or tissues.
18
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In vivo
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Procedures carried out in laboratory or field conditions using entire, living organisms.
19
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Independent data sets
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Repeated data sets that are collected in different labs by different workers and at different times but under the same general conditions.
20
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Independent variable
A
Experimental variable that is purposely altered by the investigator.
21
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Multifactorial
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An experiment situation in which there is more that one dependant variable.
22
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Negative control
A
An experimental aspect in which the independent variable is set at zero, or at no treatment, with the aim of producing a negative result.
23
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Observational studies
A
Work that is usually carried out in the field or in vivo, and usually produces qualitative data.
24
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Pilot study
A
A small-scale study conducted to refine values for independent and controlled variables prior to conducting an experiment.
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Placebos
Negative controls used in drug and vaccine trials that do not contain the active ingredient being tested.
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Positive control
An experimental aspect set up to show that a system is capable of detecting a positive result should it occur.
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Precision
The closeness of repeated measurements of a variable.
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Random sampling
Sampling in such a way as to ensure that all individuals have an equal chance of being selected in order to to obtain a statistically representative sample.
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Randomised block design
Experimental protocol in which the effects of potentially confounding variables can be reduced.
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Range
The difference between the two extremes of a set of numerical data.
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Reliability
The degree of confidence that an experimental procedure can produce consistent values.
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Representative sample
A sample that shares the same mean and same degree of variation about the mean as the population as a whole.
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Stratified sample
Dividing a population into groups or strata before carrying out the sampling to take account of a gradient, such as a slope, tidal cycle or seasonal changes.
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Validity
Refers to the control of variables to produce fair testing.
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Variable
Factor in an experiment that is changeable or can change.
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Box plot
Graph showing a data set arranged into numerical order and divided into an upper quartile, an interquartile range and a lower quartile.
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Error bar
Line through a data point drawn parallel to an axis showing the variation in the data for that point or the extent of the data for which there is 95% expectation that the true mean lies along it.
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Line of best fit
Straight line drawn through a scatter plot that indicates the trend shown by the data.
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Mean
Measure of central tendency obtained by summing data and diving by the number of individual items of data.
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Median
Measure of central tendency obtained by identifying the middle value of a data set.
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Mode
Measure of central tendency obtained by identifying the most common value in a data set.
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Qualitative data
Data with descriptive values.
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Quantitative data
Data with numerical data.
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Ranked data
Data that has been transformed into arbitrary groups.
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Standard deviation
Value given for the spread or variation in data.
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Standard error of the mean
Value for the standard deviation of sample means to the overall mean of a data set.
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Abstract
A brief outline of the aims and findings of an investigation.
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Aim
Statement that links the independent and dependent variables.
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Anomalous result
Result data that clearly does not fit in with the remainder of the data obtained; it may be discarded if sufficient doubt about it exists.
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Citations
A brief statement of the origin or source of a statement or of data.
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Discussion
Consideration of the findings of an investigation, including placing results into context and against existing knowledge.
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Evaluation
Consideration of methods and results leading to statements regarding possible errors and including suggested improvements.
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Chiasmata
A point at which paired chromosmes remain in contact during the first metaphase of meiosis, and at which crossing over and excahnge of genetic material occurs between the strands.
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Crossing over
The exchange of genetic material between non-sister cromatids of two homologous chromosomes that result in recombinant chromosomes during meiosis.
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Cytokinesis
The physical process of cell division, which divides the cytoplasm of a parent cell into daughter cells.
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Hermophrodites
Species that have functioning male and female reproductive organs in each individual.
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Heterogametic
Dissimilar sex chromosomes, e.g. XY
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Homogametic
Sex chromosomes that do not differ in morphology, resulting in only one kind of gamete, e.g. XX
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Homologous pair
A pair of chromosomes of the same size, centromere position and sequence of gene - one from each parent.
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Horizontal gene transfer
Inheritance of genetic information within a generation.
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Independent assortment
Formation of random combinations of chromsomes in meiosis.
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Linked genes
Genes located on the same chromosome.
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Meiosis
The division of the nucleus that results in the formation of hapliod gametes from a dipliod gameyocyte.
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Parthenogenesis
Development of an offspring from a female gamete without fertilisation.
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Recombination
The establishment of new combinations of alleles following crossing over.
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Vegatative cloning
Any form of asexual reproduction occuring in plants which a new plant grows from a fragment of the parent plant or a specialised reproductive structure.
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X chromosome inactivation
Random inactivation of one x-chromosome to prevent a double dose.
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Absolute fitness
The ratio between the number of individuals of a particular genotype after selction to those before selection.
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Bottleneck effect
A sharp reduction in the size of a population due to environmental events or human activities.
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Co-evolution
The process by which two or more species evolve in response to slection pressures imposed by each other.
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Commensalism
Symbiosis in which only one of the species benefit (+/0).
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Evolution
The change over time in the proportion of individuals in a population differing in one or more inherited traits.
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Female choice
A mechanism of sexual selection in which females access males’ fitness and choose the males with which they will mate.
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Fitness
A measure of the tendency of some organisms to produce more surviving offspring than competing members of the same species.
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Founder effects
When the gene pool of a new population is not representative of that in the original gene pool; occurs through the isolation of a few members of a population from a larger population.
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Gene pool
The total number of genes and their alleles in a population of one species.
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Genetic drift
The random increase or decrease in frequncy of DNA sequences from one generation to the next (particularly in small populations).
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Hardy-Weinberg principle
In the absence of evolutionary influcneces, allele and genotype frequncies in a population will remain constant over the generations.
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Male-male rivarly
A mechanism of sexual selection in which males fight for females, often using weaponary such as antlers and tusks.
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Mutualism
Both species in the interaction are interdependent on each other for resources or other services; as both organisms gain from the relationship, the interaction is (+/+).
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Natural selection
The non-random increase in the frequncy of advantageous alleles and the non-random decrease in the frequncy of deleterious alleles.
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Parasitism
Symbiosis in which the parasite benefits in terms of energy or nutrients and the host is harmed as the result of the loss of these resources (+/-).
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Red Queen Hypothesis
States that, in a co-evoltionary reltionship, change in the traits of one species can act as a slection pressure on the other species.
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Relative fitness
The ratio of the number of surviving offspring per individual of a particular genotype to the number of surviving offspring per individual of the most successful genotype.
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Slection pressures
The environmental factors that influcence which individuals in a population pass on their alleles.
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Sexual dimorphism
Females are generally inconspicuous; males usually have more conspicuous markings, structures and behaviours.
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Sexual selection
The non-random process involving the selection of alleles that increase the individuals chances of mating and producing offspring.
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Symbiosis
Co-evolved intimate relationship between members of two differnt species.
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Fixed action patterns
Species-species sequence of behaviours in which one behaviour leads to the next.
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Honest signals
Characteristics that can indicate fitness and favourable alleles that increase the chances of survival of offspring or a low parasite burden, suggesting a healthy individual.
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K-selected
Breeding strategy in species that are larger, live longer and produce relatively few, larger offspring - high parental care and high probability of surviving to adulthood.
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Lek
A communal area in which two or more amles of a lekking species perform courtship displays called lekking.
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Male-male rivarly
Males will fight for domainance and access to females for mating through real or ritualised conflict.
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Monogamy
The mating of a pair of animals to the exclusion of all others.
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Parental investment
Any parental expenditure that benefits offspring; it increases the offspring’s cahnces of surviving and reproductive success at the expense of the parent’s ability to invest in other offspring.
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Polyandry
One female mates with a number of males in the name breeding season.
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Polygamy
Individuals of one sex having more than one mate.
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Polygyny
One male mates with multiple females in one breeding season.
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Reversed sexual dimorphism
Sexual dimorphism in which females are more conspicuous than males.
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R-selected
Breeding strategy in smaller, quicker maturing species, producing larger numbers of smaller offspring, limited parental care.
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Sexual dimorphism
The differences in appearance between males and females of the same species (size etc), as a product of sexual selection.
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Species-specific sign stimulus
A feature or action that indicates intent, often to start courtship.
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Antigenic variation
Change between differnt antigens during the course of infection of a host.
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B lymphocytes
White blood cells that produce specific antibodies in response to specific antigens.
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Competitive exclusion
Where the niches of two species are so similar that one declines to local extinction.
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Definitive host
The organism on or in which the parasite reaches sexual maturity.
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Ectoparasite
Parasite that lives on the surface of its host.
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Endoparasite
Parasite that lives within the tissues of its host.
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Epidemiology
The study of the outbreak and spreak of infectious diseases.
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Extended phenotype
The expression of a parasite’s geneotype into the phenotype of its host by manipulating the hosts phenotype to facilitate its transmission.
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Fundamental niche
The niche that is occupied in the absence of any interspecific competition.
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Gametocytes
The precursors of male and female gametes.
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Herd immunity threshold
The density of resistant hosts in the population required to prevent an epidemic.
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Hydrolytic enzymes
Any enzyme that catalyses the hydrolysis of a chemical bond.
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Inflammatory response
Injured or wounded areas become warm and red due to increased blood flow, bringing white blood cells for defence.
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Intermediate host
A host that is normally used by a parasite in the course of its life cycle and in which it may multiply asexually but not sexually.
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Latency
Viruses esacpe immune surveillance by integrating their genome into host genomes, existing in an inactice state.
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LEDC
Less economically developed country.
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Memory lymphocyte
Lymphocytes specific for a specific antigen; they are retained in the body following infection and can produce a secondary response to the same antigen.
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Natural killer cells
Lymphocytes responsible for destroying abnormal cells.
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Niche
A mult-dimensional summary of tolerances and requirements of a species.
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Non-specific defences
General response to infection, including phagocytosis.
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Phagocyte
White blood cell in non-specific defence, engulfing and destroying foreign antigens; may also present antigens to lymphocytes.
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Realised niche
The niche that is occupied in response to interspecific competition.
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Resource partitioning
Where the realised niches are sufficiently differnt that potential competitors can co-exist.
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RNA retrovirus
Virsues that use the enzyme reverse transcriptase to form DNA.
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Specific cellular defences
Activity of the immune system in response to a particular pathogen, triggered by antigens located on the surface of the cells.
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Transmission
The spread of a parasite to a host.
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Vaccines
Contain antigens that will elicit an immune response.
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Vector
An organism that does not cause disease itself but which spreads the parasite from one host to another.
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Virulence
The harm caused to a host species by a parasite.
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Anthropomorphism
The atrribution of human characteristics or behaviours and emotions to an animals behaviour.
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Arthropods
Joint-legged invertebrates that are identified by their segmented bod, typically with paired appendages, e.g. Drosophila Melanogaster (fruit fly), wasps, butterflies etc.
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Chordates
Sea squits and vertebrates, e.g. birds, fish etc
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Convergent evolution
The independent evolution of similar feautures in different species.
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Divergent evolution
The process wherby groups from the same common ancestor evolve and accumulate differnces, resulting in the formation of new species.
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Duration
The length of time each behaviour occurs during the observation period.
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Elusive species
Species that are difficult to see because of their habitat, behaviour or rarity.
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Ethogram
Lists species-specific behaviours to be observed and recorded in the study.
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Frequency
The number of times a behaviour occurs within the observation period.
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Hazard
Any source of potential damage, harm or adverse health effects on an individual.
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Indicator species
Species that, by their presence, absence or abundance, can give information about an environmental factor.
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Latency
The time between the stimulus occuring and the response behaviour.
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Mark and recapture
Method for estimating population size; a sample of the population is captured, marked and released (M); after an interval of time, a seconf sample is captured (C) ; some individuals in the second sample are recaptured (R) ; estimate the total population (N).
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Model organisms
Organisms that are either easily studied or have been well studied to provide information that can be applied to other species that are more difficult to study directly.
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Nematodes
Also called roundworms; unsegmented thread-like body; many of them are parasitic, living inside their host, e.g. Caenorhabditis Elegans.
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Phylogenetics
The study of the evolutionary history and relationships among individuals or groups of organisms.
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Point count
Sampling technique that invloves the observer recording all individuals seen from a fixed location.
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Quadrat
Square frame of known area for sampling sessile organisms along a belt transect.
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Remote detection
Ability to show an animal’s presence from a distance using a camera trap or scat sampling.
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Risk
The likelihood of harm arising from exposure to a hazard.
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Risk assessment
Involves identifying risks and control measures to minimise them.
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Scat sampling
Sampling technique used for elusive species whereby animal droppings are collected, which provide information about species abundance and diet.
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Taxonomy
The identification and naming of oragnisms, and their classification into groups, based on shared characteristics.
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Terrain
Physical geography of the land.
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Time budget
The amount or proportion of time that animals spend in different behaviours, or in performing different classes of behaviour.
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Transect
A line or belt across a habitat or part of a habitat along which the number of organisms of each species can be observed and recorded at regularly placed stations.
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Affinity
The degree to which a substance is attracted and tends to bind to another.
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Affinity chromatography
A technique used to separate and purify proteins based on a specific binding interaction between an immobilised ligand and its binding partner.
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Antigen
A specific protein with which antibodies can bind in an immune response.
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Aseptic technique
Procedures in place to prevent contamination, including sterilising equipment and work surfaces.
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Bright-field microscopy
Microscopy commonly used to observe whole organisms, parts of organisms, thin sections of dissected tissue or individual cells.
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Buffer
A solution used to set and maintain a particular pH.
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Centrifugation
A process that uses centrifugal forces to separate components of different densities in a mixture.
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Chromatography
A technique used to separate different substances; it has a stationary phase (e.g. paper or gel) that the moblie phase (e.g. a solvent) moves through, carrying the substance being examined; different distances are moved by substances of different solubility.
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Colorimeter
A device used to measure the absorbance of a specific wavelength of light by a solution.
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Culture media
A nutrient-rich growth medium providing the basic requirements for cell growth (amino acids, glucose, salts, water, as well as specific growth factors for animal cell lines).
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Fluorescence
The emission of light of a different wavelength to that which was absorbed.
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Fluorescence microscopy
Microscopy technique that uses specific fluorescent labels to bind to and visualise certain molecules or structureswithin cells or tissues.
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Gel electrophoresis
Technique used to separate samples of nucleic acid and protiens by size; introduced to a gel, they move through it due to an electric current; smaller fragments move furthur than the larger fragments.
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Growth factors
Proteins that promote cell growth and proliferation.
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Haemocytometer
Microscopic grid used to estimate the total number of cells within a sample.
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Hazard
Anything that poses as a potential risk or threat to an individual or the environment.
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Immunoassay
Technique used to detect and identify specific proteins; antibodies linked with reporter enzymes, e.g. casuse a colour change in the presence of a specific antigen.
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Inoculum
Starting material used to grow a culture from.
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Isoelectric point
The pH at which a solution has no net charge and will precipitate out of solution.
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Linear dilution series
A series of diltions that differ by an equal interval, e.g. 0.1M, 0.2M, 0.3M etc.
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Log dilution series
A series of dilutions that differ by a constant proportion, e.g. x10^-1, x10^-2, x10^-3 etc.
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Monoclonal antibodies
Stocks of identical antibodies that are specific to a particular antigen.
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Native gel electrophoresis
Does not contain SDS (denaturing molecule) and does not denature the molecule, so proteins are seperated by thier shape, size and charge.
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Pathogenic
Causing disease.
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Primary cell lines
A culture of cells isolated directly from animal or plant tissues; they have a finite lifespan and limited expasion capacity.
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Reporter enzyme
An enzyme linked to an antibody specific to a protein antigen; used in immunassay techniques.
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SDS-PAGE
Electrophoresis in which the gel contains SDS, which giives all the molecules an equally negative charge and denatures them, so separating proteins by size alone.
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Serum
Vitally important as a source of growth factors, hormones, lipids and minerals for the culture of cells.
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Standard curve
A garph that can be used to determine the concentration of an unknown solution.
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Supernatant
The liquid that lies above a solid residue or pellet in centrifugation.
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Turbidity
A measure of the degree to which a fluid loses its transparency due to the presence of suspended particles or cells in suspension.
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Vital staining
A technique in which harmless dye is used to stain either living tissue cells or dead cells for microscopical observation to allow a viable cell count to be made.
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Western blotting
An analytical technique used to identify and locate specific proteins in a sample of tissue homogenate extract based on their ability to bind to specific antigens.
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Allosteric enzymes
Enzymes that change conformation in response to a modulator.
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Alpha helix
Polypeptide chain coiled into a helix with hydrogen bonding occuring to maintain the arrangement.
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Alternative RNA splicing
Removal of non0coding introns from a primary mRNA transcript to leave only the coding exons; several different mature transcripts can be produced froma single primary transcript.
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Beta-pleated sheets
Polypeptide chain arranged in rows with the chain folding in parallel or anti parallel arrangements.
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Conformation
Structural arrangement of the polypeptide chains within a protein; it can be altered by factors such as pH and the binding of ligands and modulators.
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Co-operativity
Changes in binding of a target molecule to one subunit of a multiunit polypeptide changes the affinity of the other subunits for the target molecule.
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Disulfide bridge
A strong covalent bond that stabilisies the tertiary and quaternary strauctures of many proteins.
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Endoplasmic reticulum (ER)
A network of membrane tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane.
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Exon
Section of RNA that is usually retained during splicing.
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Glycoprotein
A protein with a carbohydrate added by post-translational modification.
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Golgi apparatus
A series of flattened membrance discs that packages proteins into membrane- bound vesicles inside the cell before the vesicles are sent to thier destination.
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Hydrogen bonds
Attractions between polar molecules in which hydrogen is bound to a larger atom, such as oxygen or nitrogen.
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Hydrolases
A class of enzyme that use water to break chemical bonds.
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Intron
A section of RNA usually removed durig splicing.
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Ionic bonds
A type of chemical bonding that invloves the electrostatic attraction betwen oppositely charged ions.
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Ligand
A substance that can bind to a protein; the protein has a shape complementary to the ligand to allow binding.
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London dispersion force
A temporary, weak attraction between atoms and molecules.
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Lysosome
A modified Golgi vesicle containing hydrolytic enzymes.
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Modulators
These bind to a secondary site on an enzyme to alter its conformation; positive modulators activate enzymes and negative modulators deactivate them.
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Monomer
A molecule that can bind chemically to other monomers to from a polymer.
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Non-coding RNA gene
A gene that codes for RNAs other than messenger RNA, so does not encode a protein.
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Phospholipid
Component of cell membranes.
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Polymer
A macromolecule composed of many repeated sunbunits (monomers).
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Post-translational modification
Addition of different chemical group to, or modification of, a protein to allow a particular function.
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Prosthetic group
A non-protein unit tighlty bound to a protein and necesary for its function.
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Protein kinases
Catalyse the transfer of a phosphate group from a donar molecule (usually ATP) to an acceptor.
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Protein phosphatases
An enzyme that removes a phosphate group from its substrate.
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Protein structure
Different levels of arrangement within a protein.
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Primary structure
Sequence in which amino acids are found within a protein.
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Secondary structure
Hydrogen bonding occuring within a polypeptide forming alpha helics or beta-pleated sheets.
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Tertiary structure
Bonding of many types occuring between the R groups of amino acids within a protein.
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Quaternary structure
The arrangement of multiple folded polypeptide connected together.
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Proteolytic cleavage
A major form of post-translational modification; it occurs when a protease cleaves one or more bonds in a target protein to activate, inhibit or destroy the protein’s activity.
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Proteome
The entire set of proteins expressed by a genome; it its much larger than the genome.
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R groups
Side groups that allow different bonding between amino acids and give them their wide range of functions.
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Basic R groups
Contains an amine functional group and produces a basic solution because the extra amine group is not neutralised by the acidic group.
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Acidic R groups
Contains an acidic functional group and produces an acidic solution because the extra acid group is not neutralised by the amine group.
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Polar R group
Group that prefers to exist in water environments.
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Hydrophobic R groups
Composed mostly of carbon and hydrogen and tends to be repelled from water.
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Rough endoplasmic reticulum (RER)
Organelle made up of membranes with ribosomes attached.
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Signal sequence
A short stretch of amino acids at one end of the polypeptide that determines its eventual location in a cell.
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Smooth endoplasmic reticulum (SER)
A membranes organelle found in most eukaryotic cells; its main functions are the synthesis of lipids and steriod hormones.
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Turns
Secondary structure that reverses the direction of a polypeptide chain.
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Vesicles
Small membrane-bound compartments filled with liquid.
