Bio term 1

Population

A group of indivudals belonging to the same species that live in a particular area at the same time

Biomes

regions of the world with similar climate, animals and plants

Community

Sum of all living organisms in a habitat

Environment

Biotic and abiotic factors of an area

Ecosystem

Ecological system including biotic and abiotic factors and the interactions between them

Named after dominant species present

Habitat

An area or environment within an ecosystem where an individual of a species lives, feeds and reproduces

Biosphere

Sum of all ecosystems across the world

Terrestrial

On land and is based on climatic variation

Include: tundras, deserts, temperate grasslands, forests, etc.

Aquatic

In water, and the largest part of the biosphere

Include: oceans, lakes, creeks, streams, etc.

Abiotic factors in environment

Climate = atmospheric weather of an area measured and averaged over a long period of time

Humus = decomposition of plant and animal debris which can be a limiting factor

Substrate = supporting surface on which an organism grows

Soil type = location, depth, texture, pH, colour

Biotic factors in environment

Abscence or prescence of organisms

Predators

Competitors

Mates

Parasites

Aquatic environments abiocitc factors

• Classified according to depth

• First 200 meters of ocean depth = photic zone

• As ocean depth increases, organisms feel effects of increased pressure

relationships between organisms

affect biodiverisity benefitng or harming it

Competitions

Organisms compete for a resource that limits their survival

For example, sea anomea compete with each other for food resource of tiny plankton and fish

Collaboration

Members of the same species work together for their benefit

For example, lions work together to isolate and trap gazelle in the savannah

Intraspecfific

Relationships between organisms in the same species

Interspecific

Relationships between animals in different species

Predator-prey

Predator kills prey for consumption

There will always be more prey than predator

For example wolves hunting moose

Symbiosis

Relationships where two or more organisms live together and at least one of them benefits

Parasatism

Parasite benefits at the expense of the host

For example, the dog heartworm lives on the dog

Mutualism

Both organisms benefit

Without the two organisms interacting many organisms would become threatened

For example, pgymy possums collect nectar from eucalypt blossoms being pollinators

Commensalism

One organisms (commensalar) benefits while other is not harmed or benefits

For example zebra and cattly egret. Egret sits on zebra and eats insects off it

Disease - Chlamydia in koalas

Affects the koalas’ reproductive tract and reduces their ability to produce offspring

Symptoms:

• Inflamed eyes

• Wet fur around the rump

• Reproductive tract infections

Sexually transmitted

Can be treated by vaccines

Ecological niche

way in which species function in their environment

Niches including

Reproductive sites

Feeding activities

Abiotic factors helping species

Spatial habitat

Relationships

Fundemental niche

Ideal niche species would occupy if there are no predators, competition or parasites

Realised niche

Results from an organisms inability to exploit resources of its natural habitat due to restrictions

Competition exclusion principal

No 2 species can share the same niche in the same environment for an extended period of time

One species will outcompete the other

Matter

Consists of atoms and anything that takes up space and has mass

Recyles thorugh ecosystems organically or inorganically

Energy

The capacity to do work

Can be transferred or transformed

Have heat, light and chemical energy

Cannot be recycled

Sun

• Energy and matter interact

• Is the ultimate energy source

• warms atmosphere

• drives all geochemical processes

• radiant energy

• non-visible radiation

• Visable light

Lifes energy sources

Heat from the earths core supplies thermal energy to support organisms in extreme conditions

Archaea use sulfur and iron as their source of energy and matter

Geothermal energy

Heat generated from earths core

Some heat escapes to generate geothermal activity on the earth and ocean

Biogeochemical cycle

Pathway of matter through organisms and non living compounds and the chemical interactions in a surface reserviors (e.g. atmosphere)

Autotrophs

• Producers

• Synthesise orgnic compounds from inorganic materials

• Self feeding

• Plants have chloroplasts with chlorophyll allowing photosynthesis to occur

• e.g. algae

Geochemical

In crust and subcrust reserviors

Photosynthesis equation

Carbon dioxide + water → glucose + oxygen

Heterotrophs

• Consumers

• Cannot synthesise organic compounds

• Depend on autrotrophs

• e.g. animals

Biomass

The total mass of biological matter in a given area at the time of measurement that can be used as an energy source

• water = no energy

• biomass is a dry weight

• gm^-2

Productivity

% of energy entering an ecosystem that is incooperated into biomasss

Primary productivity

% of energy incooparated into biomass involving primary producerd

Gross Primary Production (GPP)

• total amount of energy that flows through producers

• kJm^-2year^-1

Net Primary Productivity

Amount of energy available to consumers

GPP - energy lost in respiration

• mass = gm^-2year^-1

• energy = kJm^-2year^-1

Photosynthetic effiency

How well a producer converts light energy into carbohydrates during photosynthesis

Photosynthetic effiency depends on

• amount of light

• temperature

• availability of raw materials

tropical forrest

• cover 4% of earths surface

• contribute 25% of worlds GPP anually

Consumers

extract energy via cellular respiration

Cellular respiration equation

Glucose + Oxygen → Carbon dioixde + water + ATP

Food chains

Monotir feeding relationships in an ecosystmes

Each different position is equal to each different trophic level

Scavangers

animals that feed on dead remains

Detritus

Chemical energy in dead plant or animals tissues

Dentrivores

Feed on detritus speeding up decay process by breaking smaller pieces

Decomposers

continue decay process and break down complex inorganic materials returning it to the soil or water

Energy loss

10% of energy in one trophic level is passed unto the next

Remaining 90% is lost to surroundings as heat and chemical energy

Trophic effeincy

% of energy at one trophic level that is transferred to another

Keystone species

Species that affects the population size of an organisms population

They are not abundant in ecosystems

There prescence or abscence can disturb ecosystems, even stable ones

Keystone species can

• Seed dispersal

• Nutrient recyling

• Predation

Purple sea star

• Predator of muscles

• When removed muscle population increases, biodiversity decreases

• Muscles displace sessile organisms

• When sea stars are reintroudced to environment they balance out muscle population

• They coexistance with other organisms having the same food and spacial requirements

Population dynamic

Ecological interactions between species that fluctuates population size over time

Carrying capacity

The maximum number of species in a population that an environment can sustain

Different geographic regions have different carrying capacities as different species have different requirements for life

Population composition

Characteristics of a population

Includes:

• Age

• Sex ratio

• Age spectrum

• Fertility rate

Spatial distrubution - Random

Irregular

e.g. wedge tail eagles

Spatial distribution - clumped

In groups

e.g. school of fish

Spatial distribution - uniform

Evenly spaced

e.g. pine plantation

Stable ecosystems

• K selected (whales, elephants, kangaroos)

• Large in size

• Have long life cycle

• Have parantel care

• Stable population growth

• Predictable

Unstable ecosystems

• R selected (rats, weeds, locusts)

• Unpredictable

• Small size

• Short life cycle

• No parantel care

• Colonising populations that increase rapidly

Open ecosystems

Migration of organisms can happen frely due to environmental changes

Closed ecosystems

No migration but birth and death rate affect population size

Growth

Number of individuals being added or subtracted per 100 or 1000 in a population per year

Growth rate equation

Population growth rate = birth rate + immigration rate - death rate + emigration rate

Population Distribution and Abundance

Density - number of organisms per unit area

Distribution - location of individuals within an area

Total abundance

Population Dynamics

Population growth rate - change in total population per unit time

Natality (birth rate): number of organisms born per unit time

Mortalitly (death rate): number of orgniams dying per unit time

Biogeochemical cycling

• model describing how chemical elements and molecules are transofrmed and stored in biological and geoical components of earths biosphere

• show the pathways of matter between living and non-living organisms in ecosystms

• can be recylced through bioligcal food webs and geological processes such as erosion

Limited resources can consist of

• availability of resources

• predation

• disease

Biotic potential

Rate at which a population would grow if there unlimited resources

Boom and Bust cycle

common in r selected species

rapid increase and equally rapid drop off

when the environment is favourable, population increases rapidly

for example summer versus winter

Predator-prey cycle

one population follows another rise and decline

explain why endagered species are large carnivores

humans decide to kill larger spcies prey, the carnivore will starve and they can no longer reproduce

Quadrant

A sqaure, circular or rectangular frame in random locations that measure an organisms population density

Population size

total area/area sample x total number of organisms counted

Population density

number of individuals/area sampled

Transect

line drawn across a community that estimate distributution of species in a community

Capture Mark Recapture

1. Capture

   • animals are caught randomly without being hurt

2. Mark

   • animals are marked so that it is not obvious to predators or harmful

   • they are then returned to habitat to interact with unmarked individuals

3. Recapture

   • another random sample is taken and the total number of indivudals caught in the second sample is recorded with the numer marked in the second sample

Carbon

Is an organic matter that is the main source of energy as well as the chemical building blocks of a cell

Carbon cycle

Biogeochemical cycle where carbon is exchanged between biosphere, lithosphere, hydrosphere and atomosphere

It is stored in resirvoirs

Carbon cycled continued

• If there are no decomposers, the cycle will still cycle for some time

• in anerobic conditions, decomposers may be unable to break down all waste and remains. Waste and remains clump together to form fossil fuels over millions of years

Decomposition

• matter is transfered through biotic and abiotic components

• dentrivore feed on detritus (waste) and scavangers feed on dead animals. this is then continued by decomposers breaking them down into organic materials allowing organic matter to re-enter the food chain

Biodiveristy

The great vareity of life that exists in biosphere

Biodiversity 3 levels:

Ecosystems - range of ecosystems in a biosphere

Species - range of different species in an ecosystem

Genetic - genetic variety in a gene pool coding for all inherited traits

Biodiveristy hotspot

A region with numerous amount of endemic speices that are threatened or endangered

Biodiveristy hotspot must have

1. At least 1500 endemic vascular plants

2. Have lost at least 70% of primary vegetation

Spatial scales

Space being occupied

Temporal scales

Provide details about biodiversity over a specific period of time in a certain area

Biological species concept

Members of the same species are able to reproduce to produce fertile offspring given they are not prevented by a physical barrier

Morphological species concept

Mainly used in fossils

Characterises species by their morphology

Phylogenetic species concept

identifies a species being the smallest group of organisms who all trace back to a common ancestor

Limitations of biological species concept

• cannot be used for fossils as it is hard to know who they sexually interacted with

• if 2 species have populations that overlap, hybrids can occur

• asexual species cannot be applied

why classify

• allows of bioligsts to communicate with each other

• analyses info about organisms

• see patterns and trends between the relationship of organisms

• provides a method of sorting

Classfication is based off

• methods of reproduction

• physical characteristics

• molecular sequences

Methods of reproduction

Reproduces sexually (gametes from 2 species are mixed) or asexually (no gametes produced)

Eutherian

Mother gives birth to live young after gestation