Levels of Organization in Living Things

Levels of Organization in Living Things A Look at Ecology as a science Ecology • Ecology - study of interactions between biotic and abiotic factors of organisms in environmental sys

Levels of Organization in

Living Things

A Look at Ecology as a science

Ecology

•  Ecology - study of interactions

between biotic and abiotic factors

of organisms in environmental systems

– Biotic factors -living things (plants,

animals, and decomposers)

– Abiotic factors - nonliving things

(air, water, sunlight, and land)

Levels of Organization

•  Living things are part of a whole The

parts in levels of organization are:

–  9 The Biosphere

–  8 Ecosystems = Biomes

–  7 Communities

–  6 Populations

–  5 Organism

–  4 Organ Systems

–  3 Organs

–  2 Tissues

–  1 Cells

The Biosphere

• Biosphere - the living world

and all Biotic and Abiotic Factors that affect life within

it

Ecosystems = Biomes

•  Ecosystem – several types of living things

live in environment and interact between

themselves and nonliving surroundings

•  Biome - global ecosystem located in a

specific portion of the world

–  Deserts, oceans, and forests are examples of

ecosystems and Biomes

–  Biomes are characterized by the quantity of

rainfall per year.

Ecosystems in Biomes

•  A deer, rabbit, and all the plant populations that live in a grasslands area and the lake, air, and rocks are part of an ecosystem

Communities

•  Community - made up of

populations that interact with each

other

– Rabbits and hawks may be part of a

community

– There are many communities in a

Biome

– Communities may be separated by

living or non-living matter (mountain

or other boundaries are common)

Populations

• Population - a group of

organisms that mate with one another and live in the same place at the same time

– A deer or several deer may belong to a population as long as

it can interact with other deer in the same area

Organisms

• Organism - a specific species

of plant, animal, bacteria,

fungus or other living thing

that lives in a specific area

– You and I are both organisms

So too can be said for my pet

cat

Smaller Than Organisms

•  There are two types of organisms

–  single cellular or multi-cellular organisms –  multi-cellular organisms have may be broken down into the following components:

– Organ systems - a set of organs inside

an organism that carry out a specific function (digestion, circulation, respiration, etc.)

– Organ - a set of tissues connected tthat

carry out a specific function for a living thing (an example of an organ may include the heart, the lung, the brain, etc.)

Smaller Components Yet

•  Tissues - 2 or more cells carry out a

specific function for an organism

•  Cell - the smallest unit of life that has

all the characteristics of living things

–  In multi-cellular organisms there are

several types of cells located in different

parts of the living organism that carry out

specific functions

Organisms in Ecosystems

•  Habitat - the place where an

organism lives

•  Niche - the role a species has in

its environment

•  Cooperation and competition for biotic and abiotic parts of the environment is what ecology is about

–  Habitat and niche are a function of both

Relationships

• Symbiosis - a relationship

where two or more

organisms depend on each

other for resources

– Resources serve an organism

(such as food, shelter, etc.)

Symbiosis

•  A relationship between two organisms where one organism benefits while the

other is harmed - parasitism

•  A relationship between two or more organisms in which both organisms

benefit - mutualism

•  A relationship in which one organism benefits but the other is neither

harmed nor helped - commensalism

Food and the Trophic Levels

•  Trophic level - steps in the passage of

energy and matter through an biotic

and abiotic aspects of an ecosystem

•  Matter and energy are passed from

pieces of the living system through the

feeder levels

–  Autotroph - uses energy from the sun or

energy stored in chemical compounds to

make its food (carbohydrates)

–  Hetertroph - an organism feeds on other

organisms

More About Feeding

•  Levels of heterotrophs –

– Primary consumers (herbivores) – Secondary consumers (eat

herbivores)

– Tertiary consumers (eat the

organisms that eat herbivores)

– Scavanger - a heterotroph that eats

dead organisms

– Decomposer - a heterotroph that

breaks down and absorbs nutrients from dead organisms

Primary, Secondary, Tertiary

•  Carnivores eat meat and include

secondary and tertiary consumers

•  Herbivores eat plants and include

primary consumers

•  Omnivores eat everything and

anything and include primary,

secondary and tertiary consumers

Energy Flow

•  Food chain - linear flow of

matter through an ecosystem

•  Food web – non-linear flow of

matter and food through an

ecosystem

– Expresses all possible feeding

relationships in each trophic level

– Expressed at the community level

within an ecosystem

Energy Flows, Matter Cycles

•  Why does energy flow and

matter cycle?

•  Matter Cycles are part of the abiotic materials flow in an ecosystems:

– Matter moves through ecosystems – How matter moves will determine how life can be supported within the system

•  Water cycles between the atmosphere, ocean and land

•  All living things require water to maintain homeostasis

•  The Cycle –

–  Evaporation - vapors rise

•  Transpiration – plants evaporate water through their leaves

–  Condense – particles come together into

clouds

–  Precipitation – water particles drop out, and –  Percolation – water drains into and through

the dirt

The Water Cycle Continued

•  Water's state (solid, liquid or gas) is

determined mostly by temperature

–  The water cycle is determined then by the kinetic energy of

the particles and thus is also determined by temperature

•  The amount of water on Earth

remains constant

The Water Cycle Continued

•  Surface Runoff

–  Much of the water that returns to Earth as precipitation runs off the surface of the land, and flows down hill into streams, rivers, ponds and lakes

–  Small streams flow into larger streams, then into rivers, and eventually the water flows into the ocean

–  Surface runoff is an important part of the water cycle because, through surface runoff, much of the water returns again to the oceans, where a great deal of evaporation occurs

The Carbon Cycle

•  Carbon exists in the nonliving

environment as:

– carbon dioxide in the atmosphere

and dissolved in water

– in rocks like limestone an coral

– deposits of coal, petroleum, and

natural gas derived from

once-living things

– dead organic matter, e.g., humus

in the soil

The Carbon Cycle

•  Carbon enters the biotic world through the action of autotrophs:

•  plants, bacteria and algae

•  Use energy of light to convert carbon dioxide to organic matter

– photoautotrophs

•  Bacteria

•  Use chemical energy to convert substances into organic matter

The Carbon Cycle

•  The Carbon cycle takes in carbon dioxide

and water and produces oxygen and

carbohydrates (sugar)

•  This process is called primary productivity

•  Since there is so much water on the earth,

organisms in the ocean produce more

oxygen and that ANY OTHER organism in

the world

The Carbon Cycle

• Carbon returns to the atmosphere and water by

respiration

– All living things respire

–  Carbon dioxide, burning, decay all produce carbon dioxide (if oxygen is present)

• Complete versus incomplete combustion

The Nitrogen Cycle

•  All life requires nitrogen-compounds for protein

•  Air is made of 78% nitrogen (N 2

•  Plants get nitrogen by taking it and

–  nitrate ions (NO 3 )ammonia (NH 3 ), urea (NH 2 ) 2

•  Animals get nitrogen compounds from plants (or

•  Four processes participate in the cycling of