What is a population? What is a community?

What is an ecosystem? How is a community named?

What is competition? What is predation?

What types of defences are used by plants against predation?

What types of defences are used by animals against predation?

All of the living organisms found living together in a particular area or habitat.

A group of individuals of one species that interbreed together in a particular living place. They interbreed to produce fertile

offspring.

Often after the defining form of vegetation.

The sum of all of the organisms living in a particular area, along with the habitat and

the physical component of the environment that affects organisms.

Where one organism feeds on or eats another live organism. It can be an animal

feeding on plants or other animals or plants feeding on animals. It affects the number of

organisms in a population and the biodiversity.

When organisms compete for the same resources; for example, light, space, oxygen

and food. It can be between members of the same species or two species that have

similar or the same requirements.

Chemicals that deter predators or capture their prey

Use of colour as a warning to other organisms or as camouflage

Mimicry – mimics the appearance of another species that does have

protection Stinging tentacles or spines

Thorns and spikes to protect from herbivores

Hairs and waxy or silica secretions Use of chemicals that deter

herbivores from eating them Production of toxic chemicals

What is symbiosis? What is the difference between mutualism, commensalism and parasitism?

What is the definition of a species? How are asexually reproducing organisms classified as species?

What is the binomial system for naming species? What is the hierarchy of classification?

Why would the crimson, Adelaide and yellow rosellas be classified as sub-species? What is reproductive isolation?

Mutualism – both organisms from different species benefit

Commensalism – one species benefits but the other is unharmed

Parasitism – the prey is harmed or eaten by an organism that is smaller than it is

Relationships where there is a distinct relationship between organisms of two

different species.

Species definition is assigned by appearance and some biochemical characteristics.

A population or group of populations where the members have similar physical characteristics and the capacity to

interbreed and produce fertile offspring.

Kingdom – phylum – class – order – family – genus - species

The first word is the genus (with a capital letter) and the second word is the species

(with a lower case letter).

A biological feature that prevents gene flow between the groups, even though the

groups’ habitats may overlap; barriers that prevent fertilisation – prevent mating

between individuals or interfere with fusion of ova and sperm (or pollen).

Because although they have different appearances, they are able to interbreed and therefore must be part of the same

species.

What are some ways that reproductive isolation occurs? What is an autotroph?

What is a producer? What is a heterotroph?

What are herbivores, carnivores and omnivores? What are consumers?

What is the trophic structure of an ecosystem? What is the function of decomposers?

An organism that can convert inorganic molecules into organic molecules needed to

sustain life – ie. they undertake photosynthesis or chemosynthesis.

Breeding seasons do not coincide; differences in shape of genitalia; differences

in flower shape; different courting rituals; different pheromones being released;

sperm being destroyed in the reproductive tract; offspring are infertile (ie. unequal

number of chromosomes).

Organisms that need to feed on other organisms to obtain their nutrients.

An organism that carries out autotrophic nutrition.

Heterotrophs that consume other organisms to obtain their requrements.

Herbivores feed on producers; carnivores feed on other heterotrophs; omnivores feed

on both autotrophs and heterotrophs.

They include bacteria, fungi and earthworms. They obtain their nutrition from dead

material produced at all trophic levels. They are the recyclers of the community,

responsible for breaking down the organic material and returning essential nutrients to

the environment.

The pattern of feeding relationships in the ecosystem – ie. a food chain or web.

Can organisms be present at more than one trophic level?

What are some of the characteristics of Australian ecosystems?

What factors should be considered when determining the likely survival of a species in

a given habitat?

What effects does sunlight have on the composition of a community?

What effects does water have on the composition of a community?

What effects does temperature have on the composition of a community?

What effects does the availability of nutrients have on the composition of a community?

What effects does wind have on the composition of a community?

Arid, variable water levels, subject to fire and high salinity, poor soil with low nutrient

levels.

Yes. It will depend on what the organisms at the earlier trophic levels feed on, and it

would be represented in a food web.

It is the energy source for photosynthesising plants; competition for light can be intense in

a rainforest with plants in the understorey receiving low intensity which limits the types

of species that can grow there; in marine environments plants do not exist below 100m because there is not enough light;

phytoplankton are found near the surface; different algae have different pigments to

absorb light (different wavelengths).

Interactions with other organisms (either the same or different species)

Availability of resources Climate

Impact of human activities

Enzymes have critical temperatures that they work best at. Adaptations are quite different

in alpine regions compared to hot desert regions. Temperature also links with water availability – high temperatures lead to a

high rate of evaporation. Higher temperatures are generally associated with higher activity and growth in animals and

plants.

With high temperatures and wind accelerating evaporation, the only organisms that can survive are those that can keep water loss to a minimum;

many organisms are distributed throughout Australia based on water availability; plants have evolved characteristics such as specialised leaves that store water, waxy cuticles to prevent water

loss and needle shaped leaves with smaller surface area. Some mammals have specialised excretory

systems; fish have developed mechanisms to excrete salt from their tissues. Where water is

available there is a greater range of organisms and decomposers.

Plant species need to have deeper or more extensive root systems to provide stability in

windy regions.

Plants need to obtain essential nutrients from the soil – plants surviving in nutrient-poor soils must have mechanisms to obtain requirements (eg. Nitrogen fixing bacteria

or fungi). Insectivorous plants are often found in nutrient-poor soils, and they obtain nutrients from animal’s bodies

What effects does salinity have on the composition of a community?

What effects does wave action have on the composition of a community?

What are some examples of abiotic factors? What is productivity?

What is biomass? What are the main constraints on productivity?

Why is it important to cycle matter from the abiotic environment through living organisms

and back to the abiotic environment?

Describe the key features of the carbon cycle.

Force of waves on the intertidal rock platform are a strong environmental factor

that needs to be countered. Many shell creatures possess strong muscular tissue that

enables them to clamp down on rock substrate.

Plants and animals exposed to elevated solute concentrations need special

adaptations to prevent tissue dehydration. Several organisms excrete salts using active cellular processes to help maintain correct

salt-water balance in tissues.

The measure of how effective a community is at converting the sun’s energy (measured in

g/m2). Nett primary productivity is the proportion of energy trapped in plant tissue

that is available to consumers.

Light intensity, rainfall, soil, temperature, nutrient levels.

The energy available and the amount and quality of the resources. Humans use

fertilisers and irrigation to boost productivity (but it can be to the detriment of the

environment).

The total weight of living matter in a community.

Matter is neither created or destroyed, so it must be returned to the environment so it

can be taken up by new producers and then consumers.

Describe the key features of the nitrogen cycle.

Describe the key features of the phosphorus cycle.

What do organisms need energy for? How is energy transformed during photosynthesis?

Why is there less energy available to the next trophic level? How is energy lost at each trophic level?

What do the arrows in a food web represent? How much energy from each trophic level is available to the next level?

From light energy (from the sun) into chemical energy (stored in bonds of

molecules such as glucose).

To move, synthesise important molecules and structures, uptake vital chemicals, maintain a stable cellular environment,

defend themselves against invaders, reproduce, grow and repair tissue.

The conversion of energy from one form to another, it is not totally efficient. In food webs, much energy is lost as heat energy.

Plants use a considerable amount of the energy they trap in maintaining life

processes, respiring molecules to provide energy for movement, growth, repair, synthesis reactions and reproduction.

Approximately 10%. Flow of energy.

How does light intensity impact on productivity? What is chemosynthesis?

How is the atmosphere important for life on Earth? What causes global warming?

What is succession? How do organisms change their habitat?

Where is the best place to study succession? What types of organisms are present during different stages of succession?

A process by which simple prokaryotic bacteria, called chemoautotrophs, convert inorganic materials into organic ones using

the energy from organic molecules.

As light is the primary source of energy for most communities, it determines

productivity. For example, in the open ocean, most photosynthesis must occur at

the surface because light does not penetrate. Therefore productivity is much

less than in a typical forest.

The enhanced greenhouse effect. An increase in greenhouse gases means more heat is trapped in the atmosphere, warming the Earth. An increase in greenhouse gases is

caused by deforestation, fossil fuel burning and industrialisation.

It is a largely transparent layer that allows solar radiation to be transmitted through it,

but some gases reflect heat back into the atmosphere when it is reflected from Earth,

trapping the energy in and keeping the temperature relatively stable.

Provide shelter or food for others Change the soil structure by causing

breakdown of rock or increasing organic matter in the soil

Decompose dead material and make nutrients available for others to use

Gradual process by which the species composition of a community changes. It can be brought about by the modification of the

habitat caused by the organisms that are living there.

In early stages, opportunistic species are present

Over time, one type of community is replaced with another

As the ecosystem matures, the community is dominated by slower

growing species

In a place that is devoid of any life and colonisation begins from scratch and can

be watched over time.

What is the difference between primary and secondary succession?

What are the characteristics of succession communities?

What does biodiversity mean? What does endemic mean?

What is co-evolution? What is natural selection?

How does genetic diversity relate to extinction?

What does an exponential growth rate graph look like?

As the ecosystem matures there is more biomass but reduced productivity

There are more species in mature ecosystems As the ecosystem matures, the number of

heterotrophic species increases more than the number of autotrophic species

Mature ecosystems are more efficient at recycling nutrients

Mature ecosystems have organisms that are more specialised

Primary succession is where organisms establish themselves in a new environment.

Secondary succession is where changes occur in an environment that has been exposed to some damage or disaster.

Secondary succession is usually faster as there is more soil available.

Organisms that are found nowhere else in the world.

Refers to the variety of life forms found in the biosphere, the different sets of genes

they contain and the variety of ecosystems found in different habitats.

A process whereby those individuals that are most suited to conditions are more likely to survive and pass on their genes to the next

generation.

A process where the evolution of two species occurs together or in tandem so

that the two depend on each other.

If a population is not genetically diverse, it is more likely that there will be no members

that are able to survive environmental change.

Why is exponential growth of a population not sustainable?

What are opportunistic reproductive strategies?

What are equilibrium reproductive strategies?

Which types of species colonise areas first, opportunistic or equilibrium organisms?

What is the relationship between r and K selected species and opportunistic and

equilibrium strategists?What does ‘K’ in K-selected stand for?

What is the gene pool? What causes changes in the gene pool of a population?

Organisms that produce enormous numbers of offspring (eg. Grasses that produce vast quantities of seed). They put a lot of effort

into reproduction. Resources in the environment control their numbers and

when conditions are right, the species can flood a habitat with millions of offspring.

They produce many, small young that mature rapidly and are given little care.

As the numbers increase there are great demands placed on the resources required by the individuals; food, nutrients, water,

oxygen and poisonous wastes being to accumulate.

Opportunistic species colonise the area first. They have reproductive advantages that

enable them to reproduce rapidly, producing many offspring and approach the exponential growth rate. There is little competition from other organisms so provides ideal conditions

for proliferation of the organisms.

Organisms that have a small number of offspring that are nurtured for long periods

of time. The young are larger and have slower maturation periods. They reproduce

over a longer time span.

Carrying capacity – the maximum population density that the environment can support indefinitely. the growth rate of K-selected species follows as S shaped curve where

numbers increase slowly as the population size increases, and then numbers stabilise

around the carrying capacity.

r-strategies are used by the opportunistic species and K-strategies are used by the

equilibrium species.

Mutations – changes in an organisms DNA that gives rise to new alleles

Natural selection Gene flow – exchange of alleles

between populations; occurs by movement of organisms with different

genotypes in and out of populations and the consequent change in

frequency of genes in the gene pool

The sum of all of the alleles of all of the individuals in a population.

What is the source of genetic variation in asexually reproducing species?

What are the sources of variation in sexually reproducing species?

Can the effects of the environment cause variation that can be passed on to offspring? What does polygenic mean?

What is the theory of evolution? What is Darwin’s definition natural selection?

What is a scientific definition for natural selection? How do resistant strains of bacteria evolve?

Mutations – only way new alleles can arise

Meiosis Cell division that forms gametes

Fertilisation

Mutations are the only source of variation.

Where two or more separate genes in the genome have an additive effect to determine a single characteristic.

No. Only variation that is present in the DNA (in the gametes) can be passed on to

offspring.

The environment selects those individuals that are the best adapted or fittest. Variation between individuals give some organisms a reproductive advantage, which enables the

organism to leave more offspring surviving in the next generation.

All life forms have evolved from a single, simple common ancestor

That species change through time Evolution in a species can be

recognised by the changing frequencies of genes in populations

Variation exists between bacteria due to mutations in DNA or transfer of genes by plasmids (sections of DNA that replicate

independently of the main DNA); plasmids often contain genes for resistance to

antibiotics and bacteria can transfer them by conjugation;

A particular characteristic of an organism that convers some reproductive advantage

is the result of the expression of one or more genes. When nature selects certain

characteristics, certain gene types are being favoured or selected. This may lead to changes in the frequency of particular

alleles in the gene pool of a population.

Do individuals evolve? What is speciation?

What is geographic isolation? What is reproductive isolation?

What is the definition of extinct? Which types of organisms are most likely to become extinct?

Why do introduced species have a negative impact on the environment?

What impact to pesticides and insecticides have on the environment?

The name of the process that gives rise to the origin of new species. Populations become isolated, and changes accumulate in each population. Eventually, they are no longer

able to interbreed and produce fertile offspring.

No. Populations evolve.

Where populations of organisms are so genetically different from each other, than

even if the two populations were able to mix, interbreeding would either not be possible

or, if it did occur, then the offspring would be infertile or unable to survive.

Where geographical barriers, which could include seas, lakes, mountain ranges, grasslands, deserts or other features,

separate groups of individuals from one another, preventing the flow of genes

between isolated populations. Changes then accumulate as different abiotic and

biotic factors lead to different natural selective pressures.

Where each individual requires a large area for its home

That are mainly restricted to an island or small area

With specialised habitat requirements That live in habitats that are rare, due

to land clearance for agriculture, pasture or urban settlement

A species that can no longer be found in the wild or has not been seen in the wild for many years.

They accumulate in the tissues in higher order consumers and interfere with

processes such as egg laying (thin shells).

They compete with native species for habitat and resources or directly feed on

them They can cope with a wide range of

environmental conditions Take over burrows of other organisms

Destroy vegetation that is the habitat of native species

Exert more pressure on the environment (eg. Graze heavily)

What impact does acid rain have on the environment?

What impact do CFCs have on the environment?

What impact does heavy metal poisoning have on the environment?

What impact does excess sewage have on the environment?

What impact do fertilisers and detergents have on the environment?

What impact does radioactive waste have on the environment?

What impact does mining have on the environment?

What impact does climate change have on the environment?

They were used in aerosol sprays and refrigerants; they react with ozone and

destroy it; results in a hole in the ozone layer which increases the amount of UV radiation

reaching the Earth’s surface

When fossil fuels are burnt, sulphur and nitrogen oxides accumulate in the

atmosphere. When they combine with water vapour, they form acids that fall to Earth with rain; it reduces pH levels in the water which can kill organisms; respiratory

problems in humans; erode historical buildings.

Organic wastes from untreated or partially treated sewage or from animal farming

increases the soluble inorganic nutrients like nitrates and phosphates which increase algal

growth.

Industrial plants produce heavy metal pollutants like mercury, cadmium and

arsenic. They kill soil organisms and disrupt marine ecosystems.

Radioactive materials can accumulate in lichens which absorb nutrients from the

atmosphere, and the animals that feed on them. Radioactive materials release

radioactive particles and waves that can cause DNA damage.

Run-off water carrying fertilisers and detergents lead to excess algal growth. Eutrophication occurs when waterways

have large amounts of nutrients like phosphate and nitrate that promote

excessive algal growth. They limit growth of all other organisms except bacteria.

The average temperature of the Earth’s surface will rise by 3-4oC. This will most likely result in polar ice melting and the expansion of sea water which will lead to a rise in sea

level that will change coastal habitats. It will also lead to a habitat shift as species move to

their preferred climates.

Mining removes vegetation and topsoils which causes disruption to ecosystems.

Pollutants can end up in rivers and cause loss of organisms. Many mining companies

engage in revegetation to minimise the environmental impact.

What impact does harvesting have on the environment?

What impact does habitat clearance have on the environment?

Why is the best way to preserve species to preserve their habitat?

Why is it vital to maintain our natural vegetation?

Why do we need to develop alternative energy sources?

What effect does the increase in human population have on soil / land availability?

What changes need to be made to provide enough food for the population in years to

come?

Will the world’s water be enough to sustain the population in the future?

Extensive areas of rainforest are being destroyed to support economy of various countries. It both impacts on the organisms that live there, and

reduces absorption of carbon dioxide from the atmosphere that reduces the effects of global

warming.

Fishing is an example of harvesting. Practices like trawling and dredging often

kill large numbers of other species and lead to destruction of the seabed.

Provide a range of habitats to help maintain species diversity

Provide vegetation with deep roots which maintain water table levels and prevent

salinity Maintain and protect the soil from erosion Absorb carbon dioxide and produce oxygen

Maintain regional rainfall patterns Reduce weeds and feral animals

Destruction of habitat means destruction of food sources for native species. Conditions are ideal for the opportunistic species to move in and colonise. With introduced plants and weeds, they take over

leading to further breakdown of the remaining habitat. A habitat provides an organism with all of the things it needs to survive. Removal of native

vegetation means the ecosystem cannot maintain nutrient cycles and leads to a rise in the water table and increase in salinity, which affects other plants

and animals.

There needs to be enough land to provide sufficient food for each individual. Nearly all

of the land that can be used is already in use, and many agricultural practices are leading

to a loss of productivity in the long term due to erosion, nutrient depletion and high

salinity after removal of native vegetation.

Fossil fuels are finite (they will run out), and it is becoming more and more expensive to locate and extract the fossil fuels. We need

to advance the technology so wind, solar and nuclear power are more viable.

Many die daily from polluted water and there are severe water shortages in many

countries, so it will be essential to reduce water usage.

We need to use genetic engineering to develop varieties that are more nutritious

and able to give higher yields with less input. There also needs to be increased

resistance to pests, diseases, and the ability to grow in poorer soils.

What is happening to the biodiversity in the world?

Why is the exponential growth of the human population not sustainable?

Humans have increased their carrying capacity due to increasing technology, development of medicines and agriculture. However, the increasing size of the

human population places huge demands on resources such as food, water, energy and

biodiversity. There needs to be a spread across the world in use of contraceptives, environmental

understandings and use of farming practices that work with the environment such as using less

pesticides and insecticides.

Humans are placing the diversity of animals and plants at risk – 20% of the biodiversity is expected to be lost in the next 20 years. Human activities have led to the extinction

of many species, and we are reliant on many organisms for food, medicine, drugs

and clothing.