biology unit 3

Abiotic

Non-living things (temperature, rainfall, light, buoyancy, viscosity, day length, substrate, tide height, pressure, topography, humidity, windspeed, altitude, size/depth)

Biotic

Describes living factors in the environment.

abundance

the total number of individuals of a type/species in a given area

Adaptation

A trait or biological mechanism that helps an organism survive and reproduce by adjusting to new environments

Biodiversity

the variety of life in the world or in a particular habitat or ecosystem. Measure of variation at genetic, species and ecosystem level

biome

A group of ecosystems that share similar climates and typical organisms

climate

the weather conditions prevailing in an area in general or over a long period. General, predictable atmospheric conditions

distribution

The geographic area where individuals of a species are present. How many in each area?

diveristy index

mathematical measure of species diversity in a given community (based on richness)

Ecosystem

A biological community of interacting organisms and their physical environment.

environment

complex of physical, chemical and biotic factors that act upon organisms/community and determine form and survival

Extinction

A term that typically describes a species that no longer has any known living individuals.

habitat

the natural home or environment of an animal, plant, or other organism.

Population

group of individuals of the same species that live and breed in the same area

sclerophyll

plants found in low rainfall areas; their leathery leaves help reduce water loss

Species

A group of similar organisms that can breed and produce fertile offspring.

Topography

the arrangement of the natural and artificial physical features of an area.

substrate

The reactant on which an enzyme works.

Simpson's Diversity Index

( N-(N-1) ) / ( total n (n-1) )

N \= total number of organisms
n \= number of individuals of each species

Accounts for species richness and relative species abundance

species richness

the number of different species in a community

species diversity

The number and relative abundance of species in a biological community.

species abundance

proportion of each species in an ecosystem

competition

the struggle between organisms to survive in a habitat with limited resources. direct/indirect interaction of orgnisms that lead to a change in fitness when they share the same resource. Vie for the same resource in limited supply. The species with less adaptation and tolerance range will eventually go extinct. Niches overlap. If one out competes, no overlap. e.g. birds competing for females in mating season

Predation

An interaction in which one organism kills another for food. Predator and prey relationship. One benefits and one is harmed. e.g a snake kills a rat for food

Allelopathy

a type of interference that occurs when organisms use chemicals to harm their competitors. Affects the growth reproduction, or survival of the organism. One is unaffected/benefits and one is harmed. e.g. penicillium are fungi that secretes penicillin that kills bacteria

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed e.g. tapeworms living in a dog gut. The host is harmed and the parasite benefits.

Mutualism

A relationship between two species in which both species benefit. e.g. emus and quandong plants, the emu gets food and the plant gets fertiliser from its excrement and its seeds are spread.

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected. e.g. a bird living in a tree.

spatial scale

how species may differ at the same time in different areas (micro, meso, macro). factors such as populations and maintenance, biomes, seasons

temporal scale

how species diversity may differ in the same place over a time period (day, year, decades). factors include sunlight during the day, migration and seasons, growth and movement

Sclerophyll

plants found in low rainfall areas; their leathery leaves help reduce water loss

stratisfied sampling

a sample constructed by drawing simple random samples from 2 or more subgroups in a population. estimates population, density, distribution, environmental gradients, profiles, zonation, stratification

stratified sampling techniques

quadrats, transects, capture mark recapture

stratisfied sampling bias minimising

size and number of samples, random number generators, counting criteria, calibrating equipment, noting associated precision

Lincoln Index

a way to measure the abundance of small motile organisms

caught and marked trial 1 x caught trial 2 / previously marked trial 2

Classifying ecosystems importance

old growth forests (), productive soils (), coral reefs ()

biological classification

Grouping of organisms based on their physical traits and similarities in DNA. physical features, methods of reproduction, molecular sequences

Linnaean System

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (similarity in physical features)

asexual reproduction

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

sexual reproduction

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents

K-selected species

a species with a low intrinsic growth rate that causes the population to increase slowly until it reaches carrying capacity (less and slow reproduction, more care, low mortality, longer life)

r-selected species

a species that has a high intrinsic growth rate, which often leads to population overshoots and die-offs

molecular phylogeny

Comparison of genetic sequences used to deduce relationships.

Some regions of the DNA evolve quickly- used to compare close relatives (e.g. microsatellites)

Some regions evolve slowly- used to compare distant relatives (e.g. ribosomal RNA genes)

Cladistics

A phylogenetic classification system that uses shared derived characters and ancestry as the sole criterion for grouping taxa.

Clade

A group of species that includes an ancestral species and all its descendants.

common assumptions of cladistics

a common ancestry, bifurcation and physical change

limitations to species concept

*biological- hybrids(offsrping of 2 species mating), extinct organisms,asexually reproducing species
*morphological- variation within species tremendous
*genetic- how different is enough difference?

interspecific hybrids

hybrids between two different species e.g. mule, liger

Light into chemical energy

food chains

Energy links between different organisms in an ecosystem based on feeding habits.

food webs

A complex diagram representing the many energy pathways in an ecosystem

food pyramids

models that show the loss of energy from one trophic level to another.

loss of energy

Energy is lost between levels of food chain

Efficiency of energy transfer

Useful output energy transfer / total input energy transfer

Biomass

total amount of living tissue within a given trophic level

water cycle

The continuous process by which water moves from Earth's surface to the atmosphere and back

carbon cycle

The organic circulation of carbon from the atmosphere into organisms and back again

nitrogen cycle

The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere

ecological niche

the sum of a species' use of the biotic and abiotic resources in its environment (habitat, feeding relationship, interaction with other species)

competitive exclusion principle

Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time

keystone species

a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.

carrying capacity

Largest number of individuals of a population that a environment can support

limiting factors of carrying capacity

energy, shelter, refuge from predators, nutrient availability, water, suitable nesting sites, parasites,

J-curve

a growth curve that depicts exponential growth

S-curve

a curve that depicts logistic growth; shape of an "S." The leveling off of a J-Curve exponential growth.

ecological succession

gradual change in living communities that follows a disturbance

pioneer species

First species to populate an area during primary succession, ability to fixate nitrogen, tolerence to extreme conditions, rapid germination of species, ability to photosynthesis that make them effective colonisers

climax community

A stable, mature community that undergoes little or no change in species over time

seres

A seral community is an intermediate stage found in ecological succession in an ecosystem advancing towards its climax community. In many cases more than one seral stage evolves until climax conditions are attained. A prisere is a collection of seres making up the development of an area from non-vegetated surfaces to a climax community.

primary succession

An ecological succession that begins in an area where no biotic community previously existed

secondary succession

Succession following a disturbance that destroys a community without destroying the soil

fossil record

Chronological collection of life's remains in sedimentary rock layers

human activity effect on biodiversity

Deforestation. Tropical rainforests are particularly rich in biodiversity and are being destroyed
Habitat loss through pervasive, incremental encroachment such as that caused by urban sprawl
Pollution such as that associated with widespread pesticide use and overuse of fertiliser which are 6 and 12 times greater than they were before 1961 respectively
It is estimated that half of the species at risk are threatened by agriculture
Water use in some of the largest water catchments in the world where dams and irrigation reduce water flows
Hunting and the over-exploitation of species such as in wild capture fisheries but also for wildlife trade
Spread of invasive species and diseases through trade and travel
Climate change, as warming and changing rainfall patterns alters species ranges and the underlying water and chemical cycles which define current ecosystems
Pollution from plastic waste although its long-term effects on biodiversity are far from clear

abiotic factors examples

- availability of water and resources
- season
- climate/temp
- geographical barriers/ terrain
- fertility of soil
- humidity

biotic factors examples

- prey/predators
- human activity
- disease
- gene pool size
- mutations

Percentage cover

area occupied by species/total area

percentage frequency formula

(no. quadrats where species is found / total quadrats) x 100

Simpson's Diversity Index formula

( N-(N-1) ) / ( total n (n-1) )

N \= total number of organisms
n \= number of individuals of each species

Holdridge Life Zones

global bioclimatic scheme for the classification of land areas (rainfall, biotemp, evapotranspiration ratio, latitude, altitude, humidity)

Specht's classification system

uses the foliage cover by the tallest plants in an area and the height of those plants

ANAE

Australian national aquatic ecosystem classification

EUNIS habitat classification system

identifies all habitats in europe

species abundance formula

species density (total no./sample area) x total area

Monera

unicellular, lacks organelles, reproduce asexually, free floating DNA, capsule walls

Protista

ingestion absorption or photosynthesis, water environments, eukaryotic, most unicellular

fungi

spore reproduction, eukaryotic, chitin walls, heterotrophic and saprophytic,

plantae

autotrophs, photosynthesis, walls, cuticles

Animalia

kingdom of multicellular eukaryotic heterotrophs whose cells do not have cell walls, motile

other types of classification

species interaction, symbiotic relations, disease and pathogens

dichotomous key

a key for the identification of organisms based on a series of choices between alternative characters

parthenogenesis

type of asexual reproduction in which a new individual develops from an unfertilized egg

vestigal structure

parts of an organism that are no longer functioning and do not affect survival

geological distribution

the natural arrangement and apportionment of the various forms of animals and plants in the different regions and localities of the earth.

optimal range

the range of environmental factors to which an organism is best adapted