1. All organisms are made of cells

Cells are the smallest unit of life

2. All organisms need energy

Any living organism needs energy to

live

They take in and use energy.

3. All organisms respond to the

environment What happens to an organism

depends on the environment they are

living in.

4. All organisms reproduce

Living organisms can

make more of

themselves

Two types:

– asexual

– sexual.

5. All organisms grow and develop

Get bigger as they get older.

6. All organisms carry DNA

Carry their own genetic code

Traits are passed to offspring

7. Internal Balance (Homeostasis)

Living things maintain stable internal

conditions

Examples

– Temperature

– Water Balance

– Heart Beat

Key Knowledge:

1.Matter cycles, energy flows

2.Abiotic factors cause changes in biotic factors in a

ecosystem

Abiotic: Non-living parts of the

environment

Soil

Sunlight

Climate

Temperature

Rainfall

Nutrients

Biotic: living parts of the

environment

Plant

Animals

Decomposers

(Bacteria and Fungus)

General Organization

Organism= any individual living

thing

Population= Individual

organisms of a single species

in one area.

Community= more than one

population living in the same

area.

Example of a

Community

Different

species of

fish

Different

species of

corals

(animals)

Starfish

(animal)

Algae

(microscopic plants)

General Organization

Ecosystem= All the populations and abiotic factors in an area.

Habitat = the environment that a particular species prefers within an ecosystem

Niche= the role that an organism fills “job”

Biomes= Ecosystems with similar characteristics.

Characteristics of a Biome

No distinct boundaries

Defined by types of plants

Similar climate conditions, but may be located in a totally different part of the world (Africa and Asia)

Classification of biomes:

– land biomes

–water biomes (marine or freshwater)

Can make their own food through

energy from the sun or inorganic

substances

AKA: Primary Producer

Obtains energy by eating other

organisms,

AKA: Consumers

Types of Consumers

Primary consumers: eat producers

(herbivores)

Secondary consumers: eats both

producers & consumers (omnivores)

Tertiary consumers: top predator

(carnivore)

Trophic levels are a way of identifying

what kinds of food an organism uses.

1st trophic level= primary producers

2nd trophic level= primary consumers

3rd trophic level= secondary consumers

4th trophic level= tertiary

consumer

Decomposers & Scavengers

Decomposers feed on wastes & dead

material from all trophic levels Ex: bacteria, fungi

Scavengers are consumers that eat

dead animals (like road kill) Ex: vulture

Energy in an ecosystem is

transferred (cycles) through

the trophic levels of that

ecosystem

Biomass and Energy Transfer 1 hawk

10 snakes

100 mice feed

1000 plants feed

Rule of 10****- Only 10% of the energy is

transferred to the next

organism.

Biomass- amount of living

matter, number of

organisms, or determines

the amount of energy

Very few animals feed on only one food

source, food webs are a more accurate

picture of how animals feed.

Biological Magnification The build-up of toxins in living organisms

with movement up the trophic levels .

Toxins collect in at the top of food web because top consumers eat so much.

Examples:

DDT: Dichlorodiphenyltrichloroethane

Developed during WWII as a pesticide

Very high levels of DDT were found in top consumers.

DDT is stored in fat.

Organisms died or had reproductive problems

Banned in US and Canada during the 70’s.

Still found in almost all living things

Developing countries are still use DDT

Community Interactions

In order to sustain an

environment, organisms and

abiotic factors interact

EXAMPLES:

–Symbiosis

–Succession

Forms of Species Interaction

1. Parasitism: one organism benefits at

another’s expense (humans and tape worm)

2. Commensalism: one organism

benefits while the other is unaffected

(anemone and clown fish)

Symbiosis: relationships between two

species (3 types)

3. Mutualism: both organisms benefit

from the interaction (rhino and bird)

Forms of Species Interaction Continued

Competition: two species are fighting

for the same resources

Predation: one species hunts the

other

Ecological succession: change in the

types of species in a community

observed over time

Invasive Species A species that is brought by HUMANS into

a new environment and outcompetes the

ones already there.

They have no competitors, no diseases so

they outgrow other populations

Example: Africanized honey bees,

which will take over the hive of the

honey bees.

Example: Zebra mussels attach to

boats and cover piers within

months

Keystone Species A species that plays a key role in the

ecosystem

Increases biodiversity by keeping the number of each species in balance

– Examples Sea otter in the kelp forests

Beavers in rivers

Beaver Sea Otter

Succession

Why does succession

happen? Communities & environments

change over time

1) Primary Succession

When communities form in new areas

–Ex: volcanoes, rocks, etc

Steps of Primary Succession

1. Pioneer species appear lichens

(grow on rock & turn it into soil)

Pioneer Species: the first organisms

to occupy an area

2. Grass & small plants appear

3. Weeds & shrubs

4. Shallow trees (ex: pine trees)

5. Climax community stable & final

stage (ex: deciduous trees)

Climax Community

A community that

has achieved

stability and

species diversity

2) Secondary Succession

Occurs in areas that were cleared by

disturbance (fire, tornado, floods, etc)

– faster than primary (soil already formed)

Same as primary except pioneer

species are grasses instead of lichens

Succession

leads to…..

1.Birth Rate

2.Death Rate

3.Immigration (movement into an area)

4.Emigration (Movement, exiting an area)

FACTORS THAT AFFECT

POPULATION GROWTH

Exponential Growth J-shaped curve on a graph

Population doubles every generation

Humans are reproducing this way!

Humans - Trouble ahead?

Logistic Growth S–shaped curve on graph

How real growth looks

Populations grow fast early, then slow

down, as we get closer to CARRYING

CAPACITY

Biomass

and

energy transfer

at the lowest

trophic level

determines the

carrying capacity of

the ecosystem.

Carrying Capacity

Maximum # of individuals a population

can support

– Populations will increase to carrying

capacity, and they decrease again once

they have reached it.

Limits to Pop. Growth

1. Density-dependent limiting factors - reduce population growth with that

depends on current population size

– Affect crowded populations

Disease

Competition (for shelter, food, water)

Predation (predator eats prey)

How might the

bubonic plague

have been

different if the

medieval

populations

didn’t live so

close to each

other?

2. Density-independent limiting factors

– environmental factors affecting a

population regardless of size

– Affect all populations (crowded or not)

Weather

Natural disasters (fire, etc)

Human activities

Would the

physical

effects of

hurricane

Katrina be

any different

in a town of

100, then in a

town of

100,000?

New Orleans, LA

Gulf Port , MS

All matter essential for life moves in cycles between living things & the

environment

Examples of cycles:

carbon cycle

water cycle

nitrogen cycle

Why is carbon important to us?

1) Carbon is used to make hair,

muscle, & skin

2) Carbon stores energy so living

things can think, move, etc

3) Fossil fuels (gas, coal, oil) are

made from carbon

Where is carbon found in the environment?

1. atmospheric gas (CO2)

2. rocks (limestone, diamonds)

3. fossil fuels (oil, coal, etc.)

How does carbon enter living things?

1) CO2 gas enters plants

2) Photosynthesis allows plants to

change CO2 into a sugar

3) Animals then get carbon by eating

the sugar found in plants

How does carbon get back

into the environment?

1. Plants & animals release CO2 during respiration

2. Burning of wood & fossil fuels

3. Using electricity, (most power plants use fossil fuels)

4. Cow farts (seriously)

5. Decomposition when bacteria and fungus break down tissue of dead things

How are fossil fuels formed?

1. When living things die & fall to

the bottom of water, they are

buried & compressed

2. They eventually form coal,

petroleum, or natural gas

So what’s the cycle?

the 2 main steps are

photosynthesis & respiration!

The Carbon Cycle

The movement of carbon through the

environment

2 major driving forces

1. Photosynthesis- plants and algae take up

CO2 from the air or water to make sugar

2. Cellular Respiration- consumers use

sugar for energy and release CO2 into the

air or water

Future Predictions

Due to humans using more fossil fuels, more CO2 is released each

year

this may result in global warming since CO2 traps heat (remember the

greenhouse effect)

What is global warming?

Facts about Nitrogen

78% of air is nitrogen gas (N2)

Living things can’t use nitrogen

when it’s a gas (N2)

Why do living things need

Nitrogen?

To make amino acids & proteins

To make DNA

The Nitrogen Cycle

Step #1

Nitrogen gas (N2) is found in the

atmosphere

Step #2

”Nitrogen Fixation”: Bacteria

living at the roots change

the N2 gas into a usable

form like ammonia or

nitrates

Lightning also “fixes” nitrogen

Step #3

Plants then use the ammonia

or nitrates in the soil

Step #4

Animals get nitrogen from

plants by eating them

Step #5

When plants & animals die, the nitrogen in them is released back into the atmosphere as a gas (N2)

This is done by denitrifying bacteria

Step #6 Nitrogen gas is released back into the

atmosphere

What are the two process

that are responsible; for

cycling Carbon in the

environment?

What things add carbon?

Which things take it away?

Photosynthesis and Cellular Respiration

Photosynthesis : take it away

Cellular Respiration, Fossil Fuels and Decaying organisms add it.

Breaking the Water Cycle

The only way for water to get back to the atmosphere is through transpiration (plant sweating)

When we cut down trees they no longer transpire

So water does not get into the air to become rain

The area becomes a desert in a very short time period

– Really bad in rainforest regions, because the soil is so shallow

HUMAN IMPACT

A Sad True Story

An Ecological Mystery

Long term study of sea otter population along

the Alaskan and Aleutian Islands

1970: Sea Otters healthy and populations

growing

1990: Sea Otter #’s declining

– Maybe due to emigration, not deaths

1993: 800 km area in Aleutian Islands studied

– Sea Otter #’s reduced by 50%

Vanishing Sea Otters

1997: Study of area repeated

Sea Otter pop. had declined by 90%

– 1970: > 53,000 Otters in the study area

– 2012: < 2800

Why?

– Reproductive issues

– Starvation, pollution, disease?

Cause of the Decline 1991: one researcher observed an orca

whale (killer whale) eating a sea otter.

Sea lions or seals are the normal prey of

orcas.

Decline in usual prey led to feeding shift.

Single orca could consume 1,825

otters/year.

Clam Lagoon (CONTROL GROUP), which

was not accessible to orcas, had no decline

in otter population

No Big Deal.. Right? Declines in ocean fish due to over fishing

and climatic changes led to a reduction in

food for sea lions & seals, so their #’s

decreased

This forced the orcas to enter into the

coastal waters where they consumed sea

otters.

Sea otters normally feed on sea urchins.

As sea otters decreased, the urchins

numbers increased.

Urchins eat kelp, and the large numbers of urchins damaged kelp forests.

The decline in the kelp forests has had an impact on many others species because of the decrease of oxygen and an increase in carbon dioxide in the water.

Other Species Affected

Bald Eagle

Mussel

Sea Stars

Seagulls