Bio unit 3

Biodiversity

Diversity of life; the number, variety, and variation of genes, species and ecosystems on Earth.

Organism

An individual life form

Species

A group of individuals belonging to the same lowest taxonomic unit, capable of breeding and producing fertile offspring

Ecosystem

Communities of organisms interacting with their physical and biological environment

Habitat

A specific location with a particular set of biotic and abiotic conditions; where an organism generally lives

Species diversity

A measure of the number and abundance of species in a community

Adaptation

A feature of an organism that enhances its ability to survive and reproduce in a particular environment

Abiotic factors

Non-living physical factors that influence organisms and ecosystems

Biotic factors

The living components in the environment that influence organisms and ecosystems

Ecosystem Diversity

A measure of the variety of different habitats, communities and ecological processes within a geographical location

Species richness

A measure of the numbers of species present and the evenness of species in relation to one another

Species evenness

The difference in the distribution of the total abundance between the species in a community

Community

All the species that occupy a particular place at a given time

Percentage cover

The percentage of a sample area covered by a target species

Percentage frequency

A measure of how often a species occurs in samples

Quadrat

A square frame used to isolate a standard unit of area so the distribution of a plant or animal can be studied

Population

The number of individuals of a species living in a particular place at a particular time

Relative Abundance

A measure of how common or rare a species is in relation to other species within a community

Simpson's Diversity Index (SDI)

A measure of diversity that takes into account both species richness and evenness (0 to 1 - closer to 1 means more diverse)

Predator

An organism that hunts, kills and eats another organism

Prey

An organism hunted and killed by a predator

Intraspecific competition

Competition between two or more individuals of the same species for resources

Interspecific competition

Competition between two or more individuals of different species for resources

Competition

Rivalry between individuals, of the same or different species, for a limited resource

Symbiosis

A relationship in which two organisms live in close association over a long period of time

Symbiont

An organism living in a symbiotic relationship with another organism

Disease

A condition that negatively affects the function of an individual that isn't caused directly by injury

Population density

A measure of the number of individuals living in a determined unit of area

Mortality

The ratio of total deaths to the total population of a species

Tolerance range

The range of a particular abiotic factor within which an organism can survive

Substrate

A surface on which an organism can grow

Distribution

Regions in which a species is found

Abundance

The number of individuals of a particular species in a specific area at a given time

Evenly spaced distribution

A type of distribution where individuals are more or less equally spaced throughout an area

Random distribution

A type of distribution where individuals are spaced randomly in no distinguishable pattern throughout an area

Clumped distribution

A type of distribution where individuals are found clustered in groups in particular parts of an area

Salinity

The dissolved salt content of water

Brackish

Slightly salty water; often found where seawater and freshwater mix

Osmosis

The movement of water from an area of high concentration to an area of low concentration through a semipermeable membrane

Asexual reproduction

The production of genetically identical offspring from a single parent

Sexual reproduction

The production of offspring that has genetic material from two parents

Cladistics

A method of grouping organisms that uses evolutionary lines of descent rather than structural similarities

Clade

A group of organisms that are believed to comprise a common ancestor and all of its evolutionary descendants

Linnaean classification

A hierarchical classification system based on physical characteristics

Hierarchical taxa

Groups of organisms classified into a taxon and arranged in order of rank

Clones

Offspring that are genetically identical to the parent

r - strategists

A species that occupy unstable environments and uses the evolutionary strategy of maintaining high growth rates, occupying less-crowded ecological niches and producing many offspring

K - strategists

A species whose population fluctuates at or near the carrying capacity (K) or the environment in which it resides

Bioinformatics

Collection and analysis of DNA using computers

Molecular sequencing

The comparison of genetic information between organisms to determine evolutionary relatedness

Phylogenetic tree

A diagram that represents evolutionary relatedness between organisms

DNA sequencing

The process of determining the nucleotide sequence of a DNA molecule

Evolutionary Relatedness

How closely two species are related by a common ancestor; species sharing more recent common ancestors are more closely related than those with less recent common ancestors

Common ancestor

The most recent species from which two or more organisms are descended; an ancestor that two species have in common

Cladogram

A branching diagram showing the evolutionary relatedness of a number of species

DNA sequence

The order of nucleotide bases that make up a section of DNA

Mutation

A small permanent change in the DNA sequence of an organism

Genome

The complete set of genetic information of an organism

Bifurcation

The division of a species into two species through divergent evolution

Hybrid

The offspring of parents of different species

Classification

The arrangement of living organisms or ecosystems into groups sharing similar characteristics

Climate

Long-term average weather patterns specific to a geographical area

Terrestrial

Relating to land, as opposed to aquatic (refers to water)

Stratified sampling

The division of the physical environment into smaller components for sampling

Zonation

The breaking of the biome into habitat zones

Transect

A measured length or strip of terrain in an environment along which individual organisms or environmental parameters are measured and recorded

Unbiased data

Data collected without influence or preference or prejudice of an external source

Error

The difference between an observed value and a true value results in the inaccuracy of results

Line intercept

A sampling technique used to estimate relative densities of a species by counting the number of individuals that lie on a straight line cutting through the community

Belt transect

An elongated area of known length and width through a particular environment in which specific community parameters are measured and recorded

Succession

The process of the diversity and populations of a community changing over time

Randomised Sampling

A method of selecting a sample from a total array in such a way that every possible sample that could be selected has an equal chance of being selected

Mitochondria

An organelle found in most living cells that facilitates energy production known as cellular respiration

Adenosine triphosphate (ATP)

A biological molecule used by living cells for energy

Cellular respiration

A metabolic reaction occurring in most living cells that release energy for movement, growth and other biological functions

Energy transfer

The movement of energy from one object or system to another (a chimp pushes another chimp)

Energy transformation

The change from one form of energy into another (light into chemical energy)

Trophic level

A hierarchical level in an ecosystem containing organisms that have the same feeding function in the food chain

Autotroph

Also called a producer; an organism that can produce its own food from inorganic molecules using chemical energy or light energy from the sun

Photosynthesis

Conversion of light energy into chemical energy by photosynthetic organisms such as phytoplankton or plants

Food chain

A flowchart showing feeding relationships between organisms

Trophic

Relating to the consumption of food and nutrients

Consumer

An organism that cannot produce its own food so needs to eat other organisms to obtain energy

Food web

A flowchart showing complex feeding relationships between several interlinking food chains

Organic

Relating to living matter

Inorganic

Relating to molecules or structures that aren't part of a living organism

Carbon

An element essential for many structures and processes in living organisms

Nitrogen

An element required to produce many biological molecules, particularly in plants

Water

A molecule essential for numerous biological processes in living organisms

Metabolic reaction

A chemical reaction that helps to maintain the biological function of an organism

Carbon Sink

A large area of vegetation, water or another naturally forming environment able to absorb and store atmospheric carbon dioxide

Nitrogen Fixation

Conversion of atmospheric nitrogen to nitrate by bacteria and cyanobacteria

Ecological niche

The role and position of a species in its environment; interactions of a species with the biotic and abiotic factors of its environment

Fundamental niche

The range of environmental factors a species can occupy without consideration for population limiting factors

Realised niche

The part of a fundamental niche a species occupies due to population limiting factors

Competitive exclusion

The exclusion of a species from a community by another organism better adapted to that particular ecological niche

Keystone species

A species that has a disproportionately large effect on the community in which it lives

Interspecific relationship

A relationship or interaction between different species within a community

Carrying capacity

The number of individuals of a species able to be supported by its habitat

Population limiting factor

Any biotic/abiotic factor that limits the continued growth of a population of a species

Exponential growth

Reproductive rate is maintained and the population continues to grow limited by resources

Immigration

The permanent movement of an individual or population of a species into a community

Emigration

The permanent movement of an individual or population of a species out of a community

Population change formula

(Births (B) - deaths (D))+ (Immigration (I) - Emigration (E))

Lincoln Index

The Lincoln Index allows conservationists to estimate population sizes of individual animal species. Individuals are captured, marked, released back into the population and recaptured.

Primary succession

Development and change in plant communities over time, eventually leading from bare ground to a climax community

Secondary succession

Successive, natural changes in plant communities in an area where a previous community has been removed

Pioneer species

The first species to colonise an area during primary succession

Climax community

A more or less stable plant community

Pioneer community

A new community forming on a previously barren landscape, composed of pioneer species

Sere

An intermediate community observed during ecological succession in an ecosystem advancing towards climax community

Ecological disturbance

A temporary change in an ecosystem that causes a significant change in the behaviour, growth and survival of organisms

Symbiotic relationship

An evolved interaction or close living relationship between organisms from different species, usually with benefits to one or both of the individuals involved