Unit 2 - All Key Areas Flashcards
Anthropomorphism
the attribution of human characteristics or behaviour and emotions to an animal’s behaviour
Arthropods
joint-legged invertebrates that are identified by their segmented body, typically with pared appendages, for example Drosophila melanogaster (a fruit fly), wasps, butterflies, spiders and crabs
Chordates
sea squirts and vertebrates, for example birds, mammals, reptiles, amphibians and fish
Convergent evolution
the independent evolution of similar features in different species
Divergent evolution
the process whereby groups from the same common ancestor evolve and accumulate differences, resulting in the formation of new species
Duration
the length of time each behaviour occurs during the observation period
Elusive species
species that are difficult to see because of their habitat, behaviour or rarity
Ethogram
lists species-specific behaviours to be observed and recorded in the study
Frequency
the number of times a behaviour occurs within the observation period
Hazard
any source of potential damage, harm or adverse health effects on an individual
Indicator species
species that, by their presence, absence or abundance, can give information about an environmental factor
Latency
the time between the stimulus occurring and the response behaviour
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 second sample captured (C); if some individuals in the second sample are recaptures (R), estimate of the total population (N) can be calculated
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
Nematodes
also called roundworms; unsegmented thread-like body; many of them are parasitic, living inside their host, for example Caenorhabditis elegans
Phylogenetics
the study of the evolutionary history and relationships among individuals or groups of organisms
Point count
sampling technique that involves the observer recording all individuals seen from a fixed location
Quadrat
square frame of known area for sampling sessile organisms along a belt transect
Remote detection
ability to shown an animal’s presence from a distance using a camera trap or scat sampling
Risk
the likelihood of harm arising from exposure to a hazard
Risk assessment
involves identifying risks and control measures to minimise them
Scat sampling
sampling technique used for elusive species whereby animal droppings are collected, which provide information about species abundance and diet
Taxonomy
the identification and naming of organisms, and their classification into groups, based on shared characteristics
Terrain
physical geography of the land
Time budget
the amount or proportion of time that animals spend in different behaviours, or in performing different classes of behaviour
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
Antigenic variation
change between different antigens during the course of infection of a host
B lymphocytes
white blood cells that produce specific antibodies in response to specific antigens
Competitive exclusion
where the niches of two species are so similar that one declines to local extinction
Definitive host
the organism on or in which the parasite reaches sexual maturity
Ectoparasite
parasite that lives on the surface of its host
Endoparasite
parasite that lives within the tissues of its host
Epidemiology
the study of the outbreak and spread of infectious diseases
Extended phenotype
the expression of a parasite’s genotype into the phenotype of its host by manipulating the host phenotype to facilitate its transmission
Fundamental niche
the niche that is occupied in the absence of any interspecific competition
Gametocytes
the precursors of male and female gametes
Herd immunity threshold
the density of resistant hosts in the population required to prevent an epidemic
Hydrolytic
enzymes any enzyme that catalyses the hydrolysis of a chemical bond
Inflammatory response
injured or wounded areas become warm and red due to increased blood flow, bringing white cells for defence
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
Latency
viruses escape immune surveillance by integrating their genome into host genomes, existing in an inactive state
LEDC
less economically developed country
Memory lymphocyte
lymphocyte specific for a specific antigen; they are retained in the body following infection and can produce a secondary response to the same antigen
Natural killer cells
lymphocytes responsible for destroying abnormal cells
Niche
a multi-dimensional summary of tolerances and requirements of a species
Non-specific defences
general response to infection, including phagocytosis
Phagocyte
white blood cell in non-specific defence, engulfing and destroying foreign antigens; may also present antigens to lymphocytes
Realised niche
the niche that is occupied in response to interspecific competition
Resource partitioning
where the realised niches are sufficiently different that potential competitors can co-exist
RNA retroviruses
viruses that use the enzyme reverse transcriptase to form DNA
Specific cellular defences
activity of the immune system in response to a particular pathogen, triggered by antigens located on the surface of cells
Transmission
the spread of a parasite to a host
Vaccines
contain antigens that will elicit an immune response
Vector
an organism that does not cause disease itself but which spreads the parasite from one host to another
Virulence
the harm caused to a host species by a parasite
Fixed action pattern
species-specific sequence of behaviours in which one behaviour leads to the next
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
K-selected (K-strategists)
breeding strategy in species that are larger, live longer and produce relatively few, larger offspring; they give a high level of parental care and offspring have a high probability of surviving to adulthood
Lek
a communal area in which two or more males of a lekking species perform courtship displays called lekking
Male—male rivalry
males will fight for dominance and access to females for mating through real or ritualised conflict
Monogamy
the mating of a pair of animals to the exclusion of all others
Parental investment
any parental expenditure that benefits offspring; it increases the offspring’s chances of surviving and reproductive success at the expense of the parent’s ability to invest in other offspring
Polyandry
one female mates with a number of males in the same breeding season
Polygamy
individuals of one sex having more than one mate
Polygyny
one male mates with a number of females in the same breeding season
Reversed sexual dimorphism
sexual dimorphism in which females are more conspicuous than males
r-selected (r-strategists)
breeding strategy in species that are smaller, mature more rapidly and produce a larger number of smaller offspring, each of which receives limited parental care and most will not reach adulthood
Sexual dimorphism
the differences in appearance between males and females of the same species, such as in colour, shape, size and structure, as a product of sexual selection
Sexual selection
selection for characteristics that have little survival benefit for the individual, but increase their chances of mating
Species-specific sign stimulus
a feature or action that indicates intent, often to start courtship
Chiasmata
a point at which paired chromosomes remain in contact during the first metaphase of meiosis, and at which crossing over and exchange of genetic material occurs between the strands
Crossing over
the exchange of genetic material between non-sister chromatids of two homologous chromosomes that results in recombinant chromosomes during meiosis
Cytokinesis
the physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells
Hermaphrodites
species that have functioning male and female reproductive organs in each individual
Heterogametic
dissimilar sex chromosomes, for example mammalian males where the Y chromosome is much smaller than the X chromosome, resulting in two kinds of gamete
Homogametic
sex chromosomes that do not differ in morphology, resulting in only one kind of gamete
Homologous pair
a pair of chromosomes of the same size, centromere position and sequence of gene; one is of maternal origin and the other paternal
Horizontal gene transfer
inheritance of genetic material within a generation
Independent assortment
formation of random combinations of chromosomes in meiosis and of genes on different pairs of homologous chromosomes by the passage of one of each diploid pair of homologous chromosomes into each gamete independently of each other pair
Linked genes
genes located on the same chromosome
Meiosis
the division of the nucleus that results in the formation of haploid gametes from a diploid gametocyte
Parthenogenesis
development of an offspring from a female gamete without fertilisation Recombination — the establishment of new combinations of alleles following crossing over
Sex chromosomes
a pair of chromosomes that can determine sex in some species
Sister chromatids
the genetically identical strands of chromosomes SRY gene — gene on the Y chromosome that determines development of a male by expressing a protein called testes-determining factor (TDF)
Vegetative cloning
any form of asexual reproduction occurring in plants in which a new plant grows from a fragment of the parent plant or a specialised reproductive structure
X chromosome inactivation
a process by which most of one X chromosome is randomly inactivated to prevent a double dose of gene products, which could be harmful to cells
Evolution
the change over time in the proportion of individuals in a population differing in one or more inherited traits.
Mutation
the original source of new sequences of DNA. These new sequences can be novel alleles; most mutations are harmful or neutral, but some may be advantageous
Sexual selection
a non-random process involving the selection of alleles that increase the individual’s chances of mating and producing offspring.
Sexual dimorphism
physical differences based on genetic differences between females and males
Male-male rivalry
Sexual selection can result from male-male rivalry, due to large size or weaponry, which can increase access to females through conflict.
Female choice
Involves females assessing the fitness of males
Genetic drift
Occurs when chance events cause unpredictable fluctuations in allele frequencies from one generation to the next.
Population bottlenecks
Can lead to genetic drift; occurs when a population size is reduced for at least one generation and has an effect on allele frequencies in the population.
Founder effects
Can lead to genetic drift and occurs through the isolation of a few members of a population from a larger, original population. The gene pool of the new population is not representative of the original pool.
Selection pressures
Environmental factors (biotic or abiotic) that influence which individuals in a population pass on their alleles.
Biotic selection pressures
include competition, predation, disease, parasitism
Abiotic selection pressures
include changes in temperature, light, humidity, pH or salinity.
Hardy-Weinberg principle
states that, in the absence of evolutionary influences, allele and genotype frequencies in a population will remain constant over generations.
Conditions to achieve HW equilibrium
No natural selection; mating must be random; no mutation; large population sizes; no gene flow.
Fitness
An indication of an individual’s ability to be successful at surviving and reproducing; it provides a measure of the tendency of some organisms to produce more surviving offspring than others.
Absolute fitness
the ratio of the number of individuals of a particular genotype AFTER selection, to those BEFORE selection.
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.
Co-evolution
The process by which 2 or more species evolve in response to selection pressures imposed by each other.
Symbiosis
Co-evolved intimate relationships between members of 2 different species.
Mutualism
A form of symbiosis whereby both organisms in the relationship are interdependent on each other for resources/other services. Both organisms gain (+/+)
Commensalism
A symbiotic relationship where only one organism benefits from the interaction (+/0)
Parasitism
A symbiotic relationship where the parasite benefits in terms of energy/nutrients and the host is harmed (+/-)
Pairs of species involved in symbiosis
Herbivores and plants; pollinators and plants; predators and prey; parasites and host
Red Queen Hypothesis
States that, in a co-evolutionary relationship, change in the traits of one species can act as a selection pressure on the other species. Both must adapt to avoid extinction.
Absolute fitness
the ratio between the number of individuals of a particular genotype after selection to those before selection
Bottleneck effect
a sharp reduction in the size of a population due to environmental events or human activities
Co-evolution
the process by which two or more species evolve in response to selection pressures imposed by each other
Commensalism
symbiosis in which only one of the species benefits (+/0)
Evolution
the change over time in the proportion of individuals in a population differing in one or more inherited traits
Female choice
a mechanism of sexual selection in which females assess males’ fitness and choose the males with which they will mate
Fitness
a measure of the tendency of some organisms to produce more surviving offspring than competing members of the same species
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
Gene pool
the total number of genes and their alleles in a population of one species
Genetic drift
the random increase or decrease in frequency of DNA sequences from one generation to the next, particularly in small populations
Hardy-Weinberg (HW) principle
in the absence of evolutionary influences, allele and genotype frequencies in a population will remain constant over the generations
Male-male rivalry
a mechanism of sexual selection in which males fight for females, often using weaponry such as antlers and tusks
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 (+/+)
Natural selection
the non-random increase in the frequency of advantageous alleles and the non random decrease in the frequency of deleterious alleles
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 (+/-)
Red Queen hypothesis
states that, in a co-evolutionary relationship, change in the traits of one species can act as a selection pressure on the other species
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
Selection pressures
the environmental factors that influence which individuals in a population pass on their alleles
Sexual dimorphism
females are generally inconspicuous; males usually have more conspicuous markings, structures and behaviours Sexual selection the non-random process involving the selection of alleles that increase the individual’s chances of mating and producing offspring
Symbiosis
co-evolved intimate relationships between members of two different species
