Unit 2 - Organisms And Evolution (word definitions) Flashcards
absolute fitness
the ratio of frequencies of a particular genotype from one generation to the next
antropomorphism
crediting animal behaviour with human emotions or qualities (personification)
antigen
a protein that may induce an immune response if it is foreign
antigenic variation
where parasites show great variety amongst different strains
apoptosis
cell death
autosome
any chromosome that is not a sex chromosome
bacteriophage
a virus that targets a bacterial host
chiasmata
the place where two homologous chromosomes come into contact with one another
civil engineering
a profession that is involved in the design and manufacture of infrastructure to improve standards of living
clonal selection
lymphocytes become amplified, with some clones used in immediate defence and other clones acting as memory cells
co-evolution
where a change in the traits of one species acts as a selection pressure on another species with which it frequently interacts
commensalism
an interrelationship between organisms of two different species in which one species in which one species benefits and the other neither benefits nor suffers
competitive exclusion principle
when two species are in intense competition with one another and the weaker of the two species becomes locally extinct
crossing over
the process where homologous chromosomes swap genetic material
cysticerosis
a parasitic tissue infection
definitive (primary) host
host where parasite reaches sexual maturity
epidemiology
the study of the outbreak and spread of infectious diseases
ethogram
chart on which observed animal behaviour is recorded
ethology
study of animal behaviour
evolution
the change, over successive generations, in the proportion of individuals in a population differing in one or more inherited traits
extended phenotype
a theory whereby the parasite modifies the host’s behaviour to increase its own transmission
fundamental niche
the niche that an organism occupies when there are no other species present competing for space or resources
gravid proglottid
the segment of a tapeworm containing both male and female reproductive organs
hermaphrodite
an organism with both male and female reproductive organs
heterogametic
dissimilar sex chromosomes e.g. mammalian males where the Y chromosome is much smaller than the X chromosome
homologous chromosomes
chromosomes of the same shape and size, same centromere position and which carry the same genes at the same gene loci
genetic drift
the random change in how frequent a particular allele occurs within a small population
immune surveilllance
white blood cells patrol the body, recognising and destroying foreign pathogens
independent assortment
takes place during meiosis I when homologous chromosomes pair up and line up along the equator - the final position of one pair is completely random relative to every other pair
inflammatory response
injured or wounded areas become warm and red due to increase blood flow, bringing white cells for defence
intermediate (secondary) host
the host that the parasite might require in order to complete its life cycle or as a means of transmission thus making it a vector
interphase
takes place at the start of meiosis when DNA replication occurs
K-selected
larger organisms that usually produce lower numbers of offspring, providing more extensive parental care and have longer life spans
lekking
makes display for females in a communal display area, then females chooses a mate
transect line
line along which quadrats are placed or samples are taken`
linked genes
genes that are on the same chromosome
lysis
the bursting of a host cell, releasing many virus particles
malaria
a serious human disease spread by mosquitoes that are infected with malaria parasite
meiosis
a special type of cell division where four haploid gametes are produced from one diploid gamete mother cell
memory cells
cloned lymphocytes that remain in the body to respond faster if the individual is exposed to the same antigen a second time
monogamy
where animals form breeding pairs, thus one male to one female
mutation
random change in DNA sequences within a population
mutualism
symbiotic relationship where both species benefit
natural killer cells
lymphocytes responsible for destroying abnormal cells
natural selection
non-random process whereby certain alleles occur more frequently within a population because they confer a selective advantage
parasite
an organism that gains food and shelter at the expense of the host
parthenogenesis
asexual reproduction whereby embryos develop from an unfertilised egg
phagocyte
white blood cell in non-specific defence, engulfing and destroying foreign antigens - may also present antigens to lymphocytes
phagocytosis
non-specific defence where phagocytes engulf foreign antigens and digest them using digestive enzymes present in lysomes
point count
sampling technique used for birds this is when you count the number of species from a fixed position. this can be compared to data collected at different times in the same position or in different positions
polygamy
Individuals of one sex have more than one mate
random sampling
individuals selected from the larger population must be chosen be chosen completely by chance
realised niche
the niche that an organism occupies when there is competition from other species
recombinant
the chromosome created when linked genes are separated during crossing over
red queen hypothesis
a theory concerning co-evolution of a parasite and its host
in a co-evolutionary relationship, change in the traits of one species acts as a selection pressure in the other species
this means that species in these relationships must adapt to avoid extinction
relative fitness
the ratio of surviving offspring of one genotype compared with other genotypes
resource partitioning
where two species occupy different realised niches, allowing them to co-exist by compromising over resources
retrotransposon
the piece of DNA that carries out reverse transcription before being inserted into a new site on the genome
retrovirus
a virus that contains RNA as its nucleic acid
reverse transcriptase
an enzyme used by retroviruses to synthesise DNA that can be inserted into the host cell’s genome
r-selected
smaller organisms that usually produce larger numbers of offspring, providing no parental care and having shorter life spans
sanitation
access to facilities for safely disposing of human waste such as urine and faeces
satellite male
male that sneaks to gain access to females
schistosomiasis
the human disease cause by schistomes reproducing sexually in the intestines
sessile
organism that is fixed in position - cannot move
sexual dimorphism
physical difference between males and females of a species
sexual selection
a non-random prodess, whereby certain alleles occur more frequently within a population because they are selected/preferred by one sex
sneaker
male that gains access to mate with females without the more dominant male knowing
stratified sampling
individuals are randomly selected from sub-groups within a population
symbiosis
an interrelationship between organisms of two different species, whereby at least one species benifits
systematic sampling
where sampling may be taken at regular/ preset intervals e.g. every 2m along the transect
taxonomy
grouping living organisms based on similarities or relatedness
terrain
the physical geography of the land
transmission
the spread of a parasite to a host
vector
the means of transmitting a parasite
vegetative progation/cloning
a form of asexual reproduction that takes place on some plants, resulting in offspring that are genetically identical to the parent plant e.g. bulbs and runners
virulence
the deleterious effect that the parasite has in the host
waterborne
transmitted by water
airborne
transmitted by air
latency
the time between the stimulus occurring and the response behaviour
frequency
the number of times a behaviour occurs within an observation period
duration
the length of time each behaviour occurs during the observation period
convergent evolution
when two species with different ancestral origins develop similar characteristics
divergent evolution
when two species diverge from a common ancestor and develop different characteristics
male-male rivalry
is generally brought about by the males large size or weaponry
this increases access to females through conflict
female choice
involves females assessing the fitness of the males
founder effect
the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. the gene pool of the new population is not representative of that in the original gene pool
the bottleneck effect
occurs when there is a disaster of some sort that reduced a population to a small handful, which rarely represents the actual genetic makeup of the initial population. this leaves smaller variation among the surviving individuals
selection pressures
the environmental factors that influence which individuals in a population pass on their alleles
e.g. of biotic factors
competition, predation, disease, parasitism
e.g. of abiotic factors
changes in temperature, light, humidity, pH, salinity
conditions for maintaining the HW equilibrium
no natural selection, random mating, no mutation, large population size and no gene flow (through migration, in or out)
fitness
the indication of an individual’s ability to be successful at surviving and reproducing
types of fitness
absolute and relative fitness
