Transcript Question - Cloudfront.net

Chapter 3:
The Biosphere
Pages 62-80
Chapter 3-1:
What is Ecology?
Pages 63-65
Vocabulary
ecology
species
population
community
ecosystem
biome
biosphere
Brain Candy
Hemoglobin is a complex
organic molecule in blood that
carries oxygen to tissues. It
contains the elements carbon,
hydrogen, iron, nitrogen,
oxygen, and sulfur. Which of
the following elements is least
common in organic molecules?
A. hydrogen
B. iron
C. nitrogen
D. oxygen
Question: How do organisms
affect one another’s survival?
Answer: No organism can live in isolation.
Organisms are interdependent and rely
on each other for things like food and
shelter.
Ecology

Study of interactions among organisms
and between organisms and their
environment
Levels of Organization
Ecologists Study:




Individual Organism
Species: a group of individuals so similar
that they can interbreed and produce fertile
offspring in nature
Population: individuals of the same species
living together in the same area
Community: different populations living in
the same area



Ecosystem: all the organisms in a
community interacting with their non-living
or physical environment
Biome: a group of ecosystems that have
the same climate and dominant
communities
Biosphere: the portion of the planet where
life exists, including land, water, and
atmosphere
*Extends 5 miles above earth’s surface and 7 miles below ocean’s
surface.*
organism

species


community 
population
ecosystem 
biome 
biosphere
Methods of Studying the
Biosphere
1.
2.
3.
Observing: using one or more of the
senses to gather information
Experimenting: performing tests in
artificial environments that mimic real
conditions or within natural ecosystems
Modeling: making predictions based on
data collected through observing and
experimenting and mathematical
formulas
Critical Thinking Question
Suppose you wanted to know if the
water in a certain stream was safe to
drink. Which ecological method
would you use and why?
Chapter 3-2: Energy
Flow
Pages: 67-73
Vocabulary
autotrophs
producers
photosynthesis
chemosynthesis
heterotrophs
consumers
herbivores
carnivores
omnivores
decomposers
detritivores
food chain
food web
trophic level
ecological pyramid
biomass
Brain Candy
A particular protease enzyme breaks
proteins down into amino acids within a
cell. The optimum temperature for the
function of this enzyme is 35° C. Which of
the following choices is the best prediction
of what could be observed in a cell
containing protease?
A. The protein concentration in the
cytoplasm would be highest at 35° C.
B. All the protease molecules in the cell
would bind to amino acids at 35° C.
C. The amino acid concentration in the
cytoplasm would be highest at 35° C.
D. No protease molecules would be found
in the cell at temperatures above 35° C.
Question: We get energy from
our food. Where does our food
get its energy?
Answer: The SUN!
(and some inorganic molecules in soil and water)
Energy Flow

Energy always flows in one direction
through an ecosystem – from autotrophs
to heterotrophs
Autotrophs


a.k.a. PRODUCERS
organisms that use energy from the
environment to change CO2 into
organic compounds (food)
Two types of producers:


photosynthesizers – use energy from the
sun (plants, algae, bacteria)
chemosynthesizers – use energy from
chemical reactions inside Earth (bacteria)
Heterotrophs


a.k.a. CONSUMERS
organisms that rely on other organisms for
their energy and food supply
Critical Thinking Question
We benefit a great deal from plants.
But, how do plants benefit from animals?
Types of Consumers





herbivore – plant eater
carnivore – meat eater
omnivore – eat both plants and animals
detritivore – eat dead plants and animals
decomposer – breakdown organic matter into
inorganic compounds like CO2, H20, NO3
Feeding Relationships
food chain: a series of steps in which
organisms transfer energy by eating
and being eaten
producer → herbivore → carnivore
food web: a linking of all the food
chains in an ecosystem
Critical Thinking Question
Why are straight-line food chains so
rare?
Trophic Levels




each step in a food chain or food web
producers make the first trophic level
herbivores make the second level
 a.k.a. first level consumers
carnivores and omnivores make up all the
remaining levels (3rd, 4th, etc)
 a.ka. 2nd, 3rd, etc. level consumers
Critical Thinking Question
Can consumers eat within their own level?
Can you think of an example?
Ecological Pyramids


A diagram that shows the relative amounts of
energy or matter contained within each
trophic level in a food chain or food web
Three types of pyramids:
1.
2.
3.
Energy
Biomass
Numbers
Critical Thinking Question
All the plants in a particular pyramid represent 450,000
calories.
Here are the next levels in the food chain…indicate the
number of calories available to the next level:
1. mice and insects
2. snakes
3. hawks
How much energy does the hawk store? How much does it
lose as heat?
Critical Thinking Question
How would an ecological pyramid of
numbers look for a forest ecosystem?
Chapter 3-3: Cycles
of Matter
Pages 74-80
Vocabulary
biogeochemical
cycles
evaporation
transpiration
nutrients
nitrogen fixation
denitrification
primary productivity
limiting nutrient
algal bloom
Brain Candy
Which of the following
members of a forest
ecosystem is directly
dependent on plants?
A. producer
B. primary consumer
C. secondary
consumer
D. tertiary consumer
Question: What happens to
rain when puddles “dry up”?
Biogeochemical Cycles



process in which elements, chemical compounds, and
other forms of matter are passed from one organism to
another and from one part of the biosphere to another
unlike energy, matter is recycled within and between
ecosystems in biogeochemical cycles
matter can cycle through the biosphere because
biological systems do not use up matter, they
transform it
Water Cycle
1. Water molecules enter the atmosphere
as a gas
•
evaporate: from the ocean and other
bodies of water
•
transpiration: evaporation of water
from the leaves of plants
•
aerobic respiration: organisms breath
contains water vapor
2. Cloud formation
•
water vapor loses heat energy and
changes back into a liquid
(condensation)
•
liquid water droplets in the air form
clouds
3. Precipitation
•
when water droplets in clouds
become large and too heavy they
fall back to Earth’s surface in the
form of rain, snow, sleet, or hail
4. Water returns to the oceans
•
runoff – water runs along the surfaces of
the ground until it reaches a river or
stream that will carry it to the ocean or
a lake
•
seepage – water goes down deep into
the ground to become part of ground
water
•
ground water – underground lakes and
streams
Critical Thinking Question
Question: 95% of the body is made up of
C, H, O, N…so how do we get them
into our system?
Nutrient Cycles
nutrient: a chemical that an organism
needs to live
Three nutrient cycles:
 Carbon
 Nitrogen
 Phosphorous
1. Carbon Cycle


Carbon is the key ingredient in the
organic compounds that make up
living things
Of all the carbon on Earth, less then
1% circulated in the biosphere
Carbon Cycle Involves:




biological processes like photosynthesis,
respiration and decomposition
geochemical processes like CO2 released from
volcanoes
human activity – burning of fossil fuels
conversion of carbon-rich remains into coal
and petroleum from pressure of the earth after
burial
CO2 is returned to the
atmosphere when:





animals break down organic compounds
for energy
fossil fuels are burned
decomposers decay the bodies of dead
organisms
volcanic activity
“waste product” of aerobic respiration
Critical Thinking Exercise
Write a short paragraph describing what
could possibly happen to a molecule of
carbon dioxide that you breathe out. Use
at least seven steps in your cycle.
Creativity is a plus!
2. Nitrogen Cycle




78% of the atmosphere is nitrogen gas
nitrogen fixing bacteria change
gaseous nitrogen into nitrogen
compounds (nitrogen fixation)
plants absorb these nitrogen
compounds through roots and
change them into proteins
animals get nitrogen in the form of
proteins when they eat plants or other
animals
When an organism dies:


decomposers change nitrogen back into
nitrogen compounds such as ammonia
(some is used by producers)
denitrifying bacteria change ammonia
back into nitrogen gas (denitrification) to
be released into the atmosphere
Phosphorous in the Biosphere



phosphorus is important in the
formation of DNA, RNA, and high
energy compounds like ATP
it is not found in the atmosphere
it is found mostly as inorganic
phosphates (PO4) in rocks and ocean
sediment
3. Phosphorous Cycle




PO4 dissolved in ocean waters is taken
in by marine organisms
on the land PO4 dissolved in the soil is
absorbed through the roots of plants
plants change these important
inorganic PO4 to organic PO4
compounds
animals get PO4 when they eat other
organisms
Nutrient Limitations:



primary productivity of an ecosystem is the
rate at which producers change inorganic
compounds into organic compounds
if a nutrient is short in supply it will limit an
organism’s growth
 called a limiting nutrient or limiting factor
farmers use fertilizers to overcome limiting
factors and increase crop production
Nutrient Limitations
continued…



these fertilizers usually contain
nitrogen, phosphorus and potassium
if too many nutrients are added to
aquatic environments this might lead
to increased amounts of algae and
other producers
 called an algal bloom
if there is not enough consumers to
eat the algae the health of the
ecosystem can be upset
Critical Thinking Question
Question: How does algal bloom actually
upset an ecosystem?
Answer: The extra algae dies, and
decomposing bacteria deplete the
oxygen in the lake. As a result organisms
that need oxygen, like fish or
amphibians, die off.
Critical Thinking Question
Native Americans taught European settlers
to bury pieces of fish with the seeds of
corn they planted. Why might this
practice ensure a good harvest?
Can you think of a current day practice that
is similar to this?