Ecology is the study how of we interact with the environment. For the sake of our survival we We eat food being plants, animals and sometimes bacteria and fungus. We all have certain adaptions that have given us greater advantage to survive the competitive environment.

Certain organisms that can live in extreme conditions are called “extremeophiles” ? They’ve adapted to live in environement that are inhospitable to most forms of life. While you might think of an extremeophile as being some exotic organism, one classically used example is the camel.

In more extreme examples some animals rely on eating other animals for food. The ones that hunt the animals are called predators, and the animals being hunted are called prey. Predators normally have binocular vision ? This means they can seee better in front of them to hunt prey, including the distance and size of the prey.

Prey animals normally have better side vision.

Other evolutionary advantages include camouflage.


Parasites are usually smaller organisms that live on a larger organism. Rather than have to kill for food, although if they get out of control it can be dangerous in some circumstances, they co share the environment of the host. The host is the organism they live off.

Some parasites are vectors, specifically in this context a vector is an organism, often a biting tick or isect that transmit a sickness or microform from one organism to another.


An ecoligical niche is a place or role than an organism plays in part of an ecosystem. Given the fact that living things have different competitive advantages it helps them survivie so they don’t all compete for the same resources.

The environment has made it difficult for some specieis to survvie. Temperature, elevation, salinity may all play a role in an organisms ability to survive.

In a forest vertical growth affects things. The less tall a plant has grown the more it is competing for resources ? Some animals eat different plants, whie other animals work synergystically with the waste products of the eco system. Seeing as though they exist in a different part of the eco system, they may inadvertently help each other co exist.


Interactions are the effects organisms in a compuunity have on each other. A community is an ineracting group in a common location. Interactions can be positive, negative or neutral. Members of a species can be competing for the same resources. Or it can be inter speciies interaction which could be competing for the same food, light, or space.

Interspecific interations refers to interactions between different species. Intraspecific, means internal or interactoins between members of the same species.


Mutualism is an interspecific interactions where members of different species get a survival benfit by interacting with one another. Symbiosis, is two different organisms living together at an advantage to both.


A generalist can live in a wide range of environmental conditions. They may have more tolerance for a breadth of food, or temperature or other factors. A specialist speices can only thrive in a narrow range of environmental conditions, or on a narrow diet or conditions. Specialists have less capacity to cope wit the change in the environement. A specialist may only survive on one type of food, or survive on a certain amount of rainfall. Generalists generally have more capacity to change.

Humans are generalists when it comes to food because of the wide variety of food we can tolerate. An example of a specalist trait is a koala bear that eats eucalytpus, without eucalyptus the koala
s eating choices would be narrowed.


Fertilisers is food or nutrition for plants. It comes in natural or artifical form, with artifical being the type deliberately put their by people in order to nourish the plant. The plant gets its nutrients from soil? Soil with nutrients gives a plant a more stable base to potentially be able to thrive from.

Humans invented fertiliser to try and control the production of farming hence creating a more stable, consistent and higher output of food and nutrients for our species. In some cases soil loses nutrients so we’ve needed to replace it with fertiliser.

Food, nutrients and energy allows more members of a species to surive and eat.

Some elements that fertiliser may contain include nitrogen, phosphorous, potassium. Fertilisers has enabled us to betternourish our race. The fertility of soil has been reported by civilisations as old as the egyptians as using minerals or manure to change or enhance the state of the soil.


Eutrophication can be an unexpected by product of adding fertilisers to the land, and having them end up in a water supply. When minerals such as nitrates and phosphates are washed into the system. This increase in nutrient concentration can encourage algae to glow which creates a green film ? on top of the water, oxygen depletation in the water, and a blockage for sunlight for plants that need to photo synthesise on the bottom.

Oxygen in normal atmospheric pressure of the earth is 20.9% oxygen. In water oxygen is approximately .0007% , or 7 ppm (parts per million) in water of good quality. Oxygen depletion, or when dissolved oxygen (DO; molecular oxygen dissolvedin the water) reduces to a point where it is detrminetal to the aquatic organisms in the system. Fish and marine life rely on dissolved oxygen in the water, much like land animals rely on oxygen in the air. Different fish rely on different levels of DO. Once oxygen concetraionts fall below a certain level, fish mortality may arise. The amount of dissolved oxygen can tell us a lot about water wuality.

The dissolved oxygen in water can come from photsynthesis and the atmospheric pressure. The two variables of photosysnethsis and atmospheric pressure can affect the oxygenation level. In theory photsysnesthic csan oxynegat e abody of wtaer more than atmospheiric pressure ? . The oxygen from ohtosysnetsis is produced by the plants in the water.

At higher atmospheric pressures there is less oxygen in bodies of water as there is less pressure to push oxygen molecules into the water.

A dead zone is a body of water with little or no dissolved oxygen. Water with no oxygen is called anoxic. It’s called that because aquatic organisms cannot survivie there. There is a greater chance of low DO at high temperatures, and salinities. There is a greater capacity for water to hold oxygen at a cooler tmperature. Once the water freezes and turns into ice, oxygen becomes unavailable to most organisms.

If warm water is on top, and cool water below it can limit the ability of the waters oxygen to mix, even though the water at the bottom may be cooler it may be lower in oxygen.

If herbicies or algicides end up in a lake, it may get rid of vegetation and deplete oxygen.

Bacteria then beings ot break down plants which releases more nutrients into the water. It’s called the algal bloom cycle?


Trophe comes from the Greek word “trope” meaning food or nourishment. Trophic diagrams show the relationship between organisms in an ecosystem. Comprising of levels, a trophic level is the position an organism occupies in a food chain, or food web.

August THienemann came up with terms: producers, consumers and reducers. Reducers are sometimes called decomposers.

Trophic level 1 is primary producers such as plants.

Trophic level 2 is usually Herbivores , usually called not primary producers, but primary consumers

Trophic level 3 is nromally carnivores, also called secondary consumers

Level 4 or 5 is apex predators, called tertiary consumers.

To draw a trophic level the wider the bar the more organisms there are at that level. As an example if one primary producer can feed many primary consumers the bar will be wider for whatever quantity is higher.

Some trophic level diagrams go by weight.


Phytohormones, phyto is Greek for plant. Auxins and gibberellins are plant hormones that regulate. Auxins are syntheised at the stem tips and travel downards. If the plant loses the tip of othe stem it loses its ability to grow towards light.

After the seed germinates the roots and shoots begin to grow. The seed releases a hormone called Gibberelins, that is required for a plant to germinate. Gibberelin also promotes elongation of internodes, thats the stem in between nodes. Gibberellins (GA’s) were first identifised as metaboliltes of the fungus (Fusarium fujikuroi). Gibberellins are produced in the plant embryo ? There are three type GA1, GA2, GA3.

It helps with stem elongation, the bolting and flowering, and seed germination.

Cytokinin’s work alongside auxins. Cytokinin’s are made in the root apical meristem ? and carried upwards. The plants deiceds roots or shoots based the ratio of cytokini to auxin. More auxin creates more roots, while more cytoinan creates for shoots. They promotes

Bananas that are unripe put in a bag with ripe bananas will ripen much more quickly. This is due to the ehylene that causes it to ripen much more quickly cell growth. It’s involved in cell growth or differentiation. Evenlyn is usually a gas? produce dby rapidly growing and ixfing cells ?

When a plant is dehydrated t produces abscisic acid that is syntheised in the chlorplasts of leaves when the plant is water stressed. Being a sign of dheydration it causes the stomata to close in the leaves to help prevent loss of water thorugh phototranspiartion