Interactions Between Organisms and their Environments
Mr. Broderick
NC SCOS Goal 5

Lesson #1: Living and non-living parts of an Ecosystem
• Objectives
– Identify abiotic and biotic factors in a given description of an ecosystem interaction
– Generate an example relationship using abiotic and biotic factors
– Determine if a solution is acidic, basic, or neutral given its pH
– Set-up an experiment to test the effect of pH on the sprouting of a lima bean
• Develop hypothesis, procedure

Key Vocabulary to Define
• Ecosystem
• Abiotic
• Biotic
• pH
• Acidic
• Basic
• Neutral

The organization of our world!
The earth is a biosphere
Ecosystems are the living and nonliving things in an area
Populations are a group of one type of organism living in an area

Hierarchy of Biology
• Ecosystems
• Communities
• Populations
• Organisms
• Organ systems
• Organs
• Tissues
• Cells
• Organelles
• Molecules

What is ecology?
• Ecology: The study of the relationship between organisms and their environment
• Example problems that ecology handles :
– How do humans affect the atmosphere and contribute to global warming?
– How does the population of wolves in an area affect the population of rabbits?
– Do clownfish (Nemo!) and anemone benefit each other?

Why does ecology matter?
• Ecology: The study of the relationship between organisms and their environment
Scenario: Imagine that there is an insect that lives on peanut plants growing on farms in
Northampton County. Is there a way that we can limit insect damage to the peanut crops in order to decrease the price of peanuts at the store by
20 cents per pound?

How do we study environments?
• Quadrant Studies: Tracking changes in a small section of the environment

How do we study environments?
• Sampling: Only measuring a small, random part of an environment

Ecosystems
• Ecosystem: An area containing an interaction of living and non-living factors in an area/region
• Example ecosystems :
– North Carolina forests (pine forests)
– Coastal Plains of NC
– Outer banks coastal water ecosystem
– Lake Gaston ecosystem

What is in an Ecosystem?
• Abiotic Factors: The non-living parts of an ecosystem
– Rocks, soil, temperature, gases in the air, light
• Biotic Factors: The living parts of an ecosystem
– Plants, animals, bacteria, fungus
• Producers : use light to make their own energy
• Consumers : eat other organisms to obtain energy
• Decomposers : break down dead organisms for energy

Word Parts!
• Placing an “a” before a word makes it an opposite or not
– Abiotic (not biotic; not living)
– Atypical (not typical)
– Anonymous (no name)

Biotic
• Humans
• Bacteria
• Fungus
• Plants
• Insects
• Amphibians
• Reptiles
• Mammals
• Birds
Abiotic
• Water
• Soil
• Wind or Air
• Gases
– oxygen, carbon dioxide, nitrogen
• Temperature
• Sunlight
• pH
– Acid or base

Abiotic or Biotic?
Biotic
(plant)
Abiotic
(rainwater)

Abiotic or Biotic?
• The air temperature is 45 degrees F = abiotic
• The soil is made of rocks and minerals = abiotic
• A bird lays eggs = biotic
• Bacteria break down dead organisms = biotic
• The pH or the water is 2 (acidic) = abiotic

Biotic
Abiotic or Biotic?
Abiotic Biotic Biotic

Which of the following is a relationship between abiotic and biotic factors?
A) The rain on an open field washes away soil
B) A hawk hunts a mouse and swoops down into the forest for the kill
C) A lake has very acidic water which causes many fish populations to die Abiotic
D) A deer grazes in a field of grasses
Biotic

Independent Work
• Read your scenario card
• Identify the abiotic and biotic factors in the scenario
• Now, find others with your letter and check your work.

Mini-Lesson: pH
• pH: the measurement of how acidic, basic, or neutral a solution is
Weakly Acidic Weakly Basic
1 ------------ 4 ----------- 7 ------------ 11 ------------- 14
Strong Acid Neutral Strong Base
(very acidic) (very basic)

Guided Examples
• Vinegar
– pH of 4
• Baking Soda
– pH of 8-9
Acidic
Basic
• Tap water
– pH of about 7
Neutral
• 1 M HCl (hydrochloric acid)
– pH of about 1
• 1M NaOH
– pH of about 14
Basic
Acidic

Guided Examples
• Which is more acidic?
A) pH of 2
B) pH of 5
C) pH of 7
D) pH of 11
• Which is more basic?
A) pH of 2
B) pH of 5
C) pH of 7
D) pH of 11

A scientist performs an experiment to see if acids have an effect on the health of a particular type of plant. Three sets of plants were treated with acidic solutions of known pH while the control set was treated with a solution of neutral pH 7.
What is the best conclusion for this experiment?
A. Acid has no effect on the health of this type of plant
B. High acidity is helpful to this type of plant
C. Low acidity is harmful to this type of plant
D. High acidity is harmful to this type of plant

Energy Transfer in an Ecosystem
NCSCOS 5.02b

Food Chains
• A food chain shows the flow of energy between the organisms in an environment

Food Chains
• Notice that the arrow points from the organism being eaten to the organism that eats it .
– Like the burger you eat goes into you
Plants  Cow (burger)  Human

What do the arrows in the food chain below indicate?
A. Sunlight
B. Energy flow
C. Heat transfer
D. Toxins

What is energy?
• The energy that is transferred in an ecosystem is stored in carbon-compounds, or organic compounds.
– Organic compounds: molecules that contain a carbon atom
• Carbohydrates: glucose, starch, cellulose (mostly plants)
• Proteins: the muscles of animals (steak!)
• Fats: in muscle of animal tissues (fatty steak!)

Food Webs
• When we put many food chains together in one ecosystem, it is called a food web

Food Webs
• Food webs show the direction that energy flows in an ecosystem.

Energy Moves in a Food Web
Other animals get energy from the fat and protein in other animals
Some animals get glucose from plants
Plants make glucose from light

Parts of a Food Web
• Producers: organisms that use light to store energy in organic compounds.
– ( examples: plants, algae, phytoplankton )

Parts of a Food Web
• Where are the producers in the food web below?

Parts of a Food Web
• Consumers: organisms that eat other organisms to get organic compounds that they use for energy
– ( examples: humans, cows, insects, birds… )

Parts of a Food Web
• Where are the consumers in the food web below?

Parts of a Food Web
• Tertiary consumers: organisms that eat secondary consumers for energy
• Secondary consumers: organisms that eat primary consumers for energy
• Primary consumers: organisms that eat producers to obtain energy compounds

Tertiary Consumer
Secondary Consumer
Producer
Primary Consumer

How is energy stored and transferred in an ecosystem?
A. In light
B. In oxygen and carbon dioxide
C. In carbon compounds like glucose
D. In the process of decomposition

Which of the following organisms is a primary consumer in the ecosystem shown?
A. Hawk
B. Rabbit
C. Mountain lion
D. Frog

Population Impacts in a Food Web
• If the population of organisms at any level of the food web changes, it will affect the population at other levels

Population Impacts in a Food Web
• If the population of producers decreases, then the population of primary consumers will decrease if they don’t have enough food.

Population Impacts in a Food Web
• If the population of primary consumers decreases, then…
– The producers will increase because there are less consumers eating them
– The secondary consumers will decrease because there is less food for them

Which organism would be most affected if the cricket population decreased?
A. Snake
B. Deer
C. Frog
D. Hawk

Energy Pyramids
• Energy Pyramids show the amount of energy at each level of a food web
– Trophic Level: the total amount of energy in all organisms at one level in the food web.

Energy Pyramids
• More energy at the bottom, decreases as the pyramid moves up the food web
Less Energy
More Energy

Energy Pyramid Labels
Tertiary
Consumers
Secondary
Consumers
Primary
Consumers
Producers

Energy Transfer in Energy Pyramids
• Each trophic level of the energy pyramid supplies energy to the level above it.
• Each transfer loses 90% of the energy
• Only 10% of the energy at a level is passed to the next level up!

Energy Transfer (percents)
0.1%
1%
10%
100%

Energy Transfer (calories)
1 calorie
10 calories
100 calories
1,000 calories

Energy Transfer in Energy Pyramids
• We can say that the energy transfer from level to level is inefficient
– (not a lot of the energy at each level makes it up)
• This means that there can’t be many levels ina food web or pyramid
– The amount of energy decreases, and it cannot typically support organisms at higher levels than tertiary consumer

Why are there a limited number of energy levels in an energy pyramid or food web?
A. Energy transfer is very efficient
B. Energy is captured as heat
C. Energy transfer is inefficient
D. Energy is not transferred in a food web

Energy Transfer and Flow
NCSCOS 5.02a, 2.05bc

How does energy enter the food web?

Better question… where does the weight of a producer come from?
How does this... become this?

Photosynthesis
• Photosynthesis: a toxin process that occurs in producers and converts light, carbon dioxide, and water into glucose (sugar) and oxygen.

Carbon
Dioxide
Water
Sunlight Glucose Oxygen

More Photosynthesis a. Photosynthesis removes carbon dioxide from the air.
b. The carbon dioxide in the air is the building block for glucose .
c. The light energy helps bond CO
2 together to make glucose.
and H
2
O

• The energy in light is now stored in the glucose molecule

Starch
Fat
(nuts)
Glucose O
2
Light CO
2
H
2
O

How do consumers get energy?
• Digestion of organic molecules
– Consumers eat other organisms to obtain organic molecules, which are forms of stored energy.
– Energy is stored in the bonds of the molecules.

The Carbon Cycle
NCSCOS 5.02a

Carbon Cycle
• Carbon is found throughout the environment
– Carbon is found in the atmosphere and in water as carbon dioxide (CO
2
)
– Carbon is found in organisms as organic molecules, like glucose (sugars) and fats
– Carbon is found buried in the ground as fossil fuels

Carbon Cycle
• Carbon is cycled, or moves
1) Atmosphere: Carbon is in the form of CO
2

CO
2

Carbon Cycle
2) Producers: Use photosynthesis to make sugars from CO
2 in the atmosphere (carbon is moved!)

C
6
H
12
O
6

Carbon Cycle
3) Consumers: Eat organic molecules and release
CO
2 into the atmosphere during respiration , or die and go into the soil

CO
2

Carbon Cycle
4) Soil: decomposers break down organisms, releasing carbon into the atmosphere OR trapping it in the ground (fossils)

Carbon Cycle
5) Fossil Fuels: carbon from some dead organisms are trapped as fossil fuel until we burn it

Carbon Cycle Stations
• Start at one of the stations
• Make your way to each different station based on a correct path through the carbon cycle
• If you can go to two different places, choose between them and then go back
• Write all answers on your sheet!
• After you are done, explain to your partner the “story” of the carbon cycle, and have them explain back to you!

Greenhouse Effect and Global Warming
Greenhouse Effect
• Heat is trapped near the Earth’s surface because once light gets in, it warms the surface but cannot escape out of the atmosphere.
– It is trapped by the gases in the atmosphere, like
CO
2

Global Warming
Global Warming
• The Earth has been warming on average.
• Could be due to increased CO
2 emissions into the atmosphere, which enhances the greenhouse effect and traps extra heat.

Global Warming
Excess CO
2
 Enhanced  Global Warming
Greenhouse
Effect

Relationships in an Ecosystem
NCSCOS 5.01

Symbiosis
• Symbiosis: a long-term relationship between two organisms in an ecosystem.

Types of Symbiosis
• Mutualism: both organisms benefit from their relationship
• Commensalism: one organism benefits , and the other is unaffected
• Parasitism: one organisms benefits , and the other is harmed

Symbiosis Summary
Relationship
Type
Mutualism
Commensalism
Parasitism
Species A
+
+
+
Species B
+
0
-

Name That Symbiosis
• Leeches feed off of the lamprey below, and eventually cause it to die.

Name That Symbiosis
• A clown fish lives among the sea anemone.
The clown fish gains protection, but the anemone is neither harmed nor helped.

Name That Symbiosis
• Ox-peckers live on the heads of the ox, eating insects and keeping the ox clean. The birds also get a place to live.

Example: The Malaria Parasite
• Species: Plasmodium Vivax
• Organism: Protist
• Disease: Malaria, which is prevalent in Africa

A. Plasmodium Vivax is a one-celled organism that is transmitted to humans through the bite of the female Anopheles mosquito
B. It enters liver cells and begins to reproduce
C. The reproductive cells infect blood cells.
D. Which causes them to lyse or burst.
E. The reproductive cells can be picked up by another mosquito, where they reproduce
(G) and are transmitted to another human
(H)

Population Growth and
Overpopulation
NCSCOS 5.03

Populations
• Population: the number of organism from one species that live in a specific area
– Examples: the human population in different cities, the squirrel population in a forest, the grass population in a meadow

Populations
• Populations are affected by many resources.
These include:
– The amount of food available in an area
– The amount of sunlight (if it is a plant population)
– The amount of water
– The competition for food/shelter
– The predators in an area

Population Growth Graphs
Birth Rate > Death Rate
A: Slow growth as a population begins to grow

Population Growth Graphs
Birth Rate > Death Rate
B: Exponential growth as population grows rapidly

Population Growth Graphs
Birth Rate > Death Rate
C: Slow-down of growth as population maxes out its resources, like food, water, or light

Population Growth Graphs
Birth Rate = Death Rate
D: Population reaches the maximum number supported by environment, the carrying capacity

Carrying Capacity
• Carrying Capacity: the maximum number of organisms in a population that are supported by the environment

Population Growth Graphs
Reaching Limit of Resources
Carrying Capacity
Exponential
Growth, no limiting resources

Carrying Capacity
• Populations are typically limited by resources
– They reach carrying capacity when there aren't enough resources to keep growing.
– Birth Rate = Death Rate.
– Logistic Growth !

Unlimited Growth
• If there are no limiting resources, populations grow exponentially .
• Birth Rate > Death Rate

Decline
• If population birth rate < death rate, the population will go down!

Which of the following graphs shows a population that is free of limiting factors?

Which of the following graphs shows a population that has reached carrying capacity?

How would a scientists determine the growth rate of a population?
A. Birth Rate + Death Rate
B. Birth Rate – Death Rate
C. Birth Rate x Death Rate
D. Birth Rate / Death Rate
Click To Go Back and Analyze The Graphs
In Terms of Birth And Death Rates (with the class)

What statement best describes the population shown in the graph below?
A. Birth rate = Death rate
B. Birth rate < Death rate
C. Birth rate > Death rate
D. Birth rate = 0

What statement best describes the population shown in the graph below at time “t”?
A. Birth rate = Death rate
B. Birth rate < Death rate
C. Birth rate > Death rate
D. Birth rate = 0

Predator vs Prey
• Predator and Prey populations can affect one another
1. As prey increases, predator will increase in response
2. As predators increase, prey will decrease
3. As prey decrease, predators will decrease

POPULATION TASK

POPULATION TASK
• Deer control is a major issue in North Carolina
• We are going to work as small groups to figure out the problems concerning deer management
• We will also brainstorm solutions to the problem.

POPULATION TASK
1) What are the effects of an overpopulation of deer? Why is it a problem?
2) What are some natural ways to control the deer population
3) What are some ways that humans can help control the deer population?

Human Population and Impact
NC SCOS 5.03

Objectives
• We can analyze the growth patterns of the human population
• We can explain the impacts of deforestation, pollution, and resource overuse on the environment
• We can inform the public about the dangers of human impacts and how to avoid resource overuse

Human Population
• Human population is currently about 6.8 billion
– Human population growth has been exponential

Population Pyramid Graphs
• Developing countries tend to have high growth rates, whereas developed countries tend to have stable growth.
– Population age distribution
• Larger at the bottom = more future growth
• Equal at each age = stable growth or even decline

• Population age distribution
• Larger at the bottom = more future growth
• Equal at each age = stable growth or even decline

Overpopulation: The Bad
• The problems with overpopulation include abuse of resources:
– Deforestation
– Fossil Fuel Overuse
– Freshwater Overuse
– Pollution
– Lack of adequate food
– Non-native species

Deforestation
• Cutting down forests leads to a loss of biodiversity: not as many different species in an area
– Can affect local food webs, other species, and even medicine!

Fossil Fuel Overuse
Burning Fossil Fuels
Excess CO
2 heat in the air, traps
Greenhouse effect enhanced
Global warming

Freshwater Overuse
• Poor water quality, not enough freshwater in areas of need
• Polluted runoff from factories

Pollution
• Acid rain:
– Sulfur and nitrogen gases released from factories into the air
– Sulfur dioxide: SO
2
– Falls in rain drops, slowly impacts pH of water, soil, etc.

Pollution
• Ozone Layer Destruction
– CFCs: chlorofluorocarbons – released into the air through old refrigerator and spray cans, destroy ozone layer.
– Low ozone leads to high UV radiation
– UV radiation: can cause skin cancer through mutation

Why you should wear sunblock!

Food
• Lack of food sources
• Most important in poor, developing countries

Introducing Non-native species
• Putting species into new ecosystems that aren’t supposed to be there
– The introduced species generally outcompete , or do better, than the native species.
– Example: pythons in the everglades.

What Can We Do?
• Use renewable resources for energy
– Water, wind, solar, and geothermal energy

What Can We Do?
• Reduce carbon dioxide emissions
• Reduce water waste
• Investigate factories and their pollution levels
• Increase public awareness of the issues

What Can We Do?
• Promote sustainable practices
– Using renewable energy, rotating crops, avoiding pesticides and toxins, making sure we keep fishing populations high, conserve resources

Bioaccumulation
NC SCOS 5.03, 5.02b

Quick Vocabulary
• Autotroph : makes its own energy, a producer
• Heterotroph : gets its energy from somewhere else, a consumer

Quick Vocabulary
• Accumulate : to gain over time

Bioaccumulation
• Bioaccumulation: the buildup of toxins in top consumers after eating many smaller organisms in a food web
– Also called biomagnification or bioamplification

Bioaccumulation
• Imagine that a toxin , a pesticide, was sprayed on the grass in the food web below. It cannot be released by the plant and is always stored .

http://www.ruralni.gov.uk/print/index/publications/press_articles/beef_and_sheep/archive-10/grass-attack.htm

Bioacummulation
• Each level of organisms above the grass in the food web will accumulate more and more of the toxin because they eat so much of the level below them
• For example, the mouse eats a large amount of grass, and stores all of the toxins in its body.
Then the snake eats many mice, storing all of their toxins. Finally the hawk eats many snakes and stores all of their toxins in its body

Eats 10 snakes= 1g
Bioaccumulation
Eats 100 mice = .1g
Eats 1,000 grasses = .001g
1 grass has 0.000001g

Bioaccumulation
Highest toxin levels
Even more toxin
More toxin, concentrated
Lots of toxin, spread out

Why is biomagnification a problem?
• What do you think?
– Depends on the type of toxin
– If the toxin is toxic, it might cause problems with the functions of an organism
• Impairs reproduction
• Kills off members of a species
• Prevents organisms from reproducing

What happens to the food web?
• What do you think?
– Decreased top consumers means more low level consumers
– More low level consumers means increased amounts of the toxic toxin!
– The top level consumers don’t stand a chance!
• Are we top level consumers? Can this happen to us?