Advanced higher biology

Anthropomorphism

the attribution of human characteristics or behaviour and emotions to an animal's behaviour

Scientific method

Observation, testable hypothesis, experimental design, gather record analysis of data, evaluation and conclusion, formation of new hypothesis

Human studies

Informed consent, right to withdraw data, confidentiality,

Animal stuff

Replace reduce refinement

More than one independent variable

Multi factorial

Observation study

Good at detecting correlation

Placebo

Without independent, measurable change in dependent variable as a result of patients expectations

If confounding not controlled

Randomised block design

Vitro

Outside living, simple, less expensive but difficult to apply to wider setting

Vivo

Using whole living org, expensive, complex, time consuming, allow study of complex interaction

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

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

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.