Chapter 3
The Biosphere
3.1 Ecology
• The study of interactions btw living
organisms & their env.
• Biosphere – whole planet where life is
– 8km above
– 11km below
3.1 Ecology
• Individual – a single organism
• Species – group of similar orgs
• Population – groups of same species inds
that live in same area
• Community – pops. that live in defined area
• Ecosystem – orgs & env in a defined area
• Biome – group of ecosystems w/ same
climate
• Biosphere – whole planet where life is found
3.2 Energy Flow
• Food energy from Ch 38
• Food chain/web
– Differences
• Chain pg 69
• Web pg 71
3.2 Energy Flow
• Producers
– All living organisms need energy
– Most organisms use light energy from the
sun
• A little goes a long way!
– Some organisms use chemical energy
– aka Autotrophs
• Orgs. able to use energy in env. (sun or chem.)
• Make their own food
3.2 Energy Flow
• Energy from the Sun
– CO2 + H2O
• Types
Light eng.
carbs + O2
– Plants
– Algae
– Photosynthetic bacteria
• Cyanobacteria most common
3.2 Energy Flow
• Energy from Chemicals
– Produce food in the absence of light
– Use inorganic molecules to make organic
molecules
– Chemosynthesis
– Mostly bacteria in volcanic areas & deep
sea vents
3.2 Energy Flow
• Consumers
– Eat other organisms
– aka heterotrophs
– Types
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Herbivores – eat only plant material
Carnivores – eat only animal material
Omnivores – eat both plant & animal material
Detritivores – eat plant & animal remains (detritus)
Decomposers – break down organic matter
3.2 Energy Flow
• Feeding Relationships
– Energy flows one way
– Energy is never lost, only converted
• Food Chains
– Linear relationship btw. producers &
consumers
3.2 Energy Flow
• Food Webs
– Too complex for a linear representation
• Trophic Levels
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Producer
Primary consumer
Secondary consumer
Etc.
Decomposers
3.2 Energy Flow
• Ecological Pyramids
– Amt. of energy matter/# orgs. at each level
– 10% energy passed on from one trophic level
to the next
– 90% lost as heat energy
• Biomass Pyramid
– Amt. living mass at each level
– Amt. food
3.3 Cycles of Matter
• Energy FLOWS
– Linear
– Converted: light  food  chemical  heat
– At end, lost as heat
• Cycles
– Continuously recycled
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Water pg 75
Carbon pg pg 77
Nitrogen pg 78
Phosphorous pg 79
Definition of “living”
Conventional definition: Often scientists say that life is a characteristic
of organisms that exhibit the following phenomena:
• Homeostasis: Regulation of the internal environment to maintain a
constant state; for example, sweating to reduce temperature.
• Organization: Being composed of one or more cells, which are the basic
units of life.
• Metabolism: Consumption of energy by converting nonliving material into
cellular components (anabolism) and decomposing organic matter
(catabolism). Living things require energy to maintain internal
organization (homeostasis) and to produce the other phenomena
associated with life.
• Growth: Maintenance of a higher rate of synthesis than catabolism. A
growing organism increases in size in all of its parts, rather than simply
accumulating matter. The particular species begins to multiply and
expand as the evolution continues to flourish.
Definition of “living”
• Adaptation: The ability to change over a period of time in response to
the environment. This ability is fundamental to the process of evolution
and is determined by the organism's heredity as well as the composition
of metabolized substances, and external factors present.
• Response to stimuli: A response can take many forms, from the
contraction of a unicellular organism when touched to complex reactions
involving all the senses of higher animals. A response is often expressed
by motion, for example, the leaves of a plant turning toward the sun or
an animal chasing its prey.
• Reproduction: The ability to produce new organisms. Reproduction can
be the division of one cell to form two new cells. Usually the term is
applied to the production of a new individual (either asexually, from a
single parent organism, or sexually, from at least two differing parent
organisms), although strictly speaking it also describes the production
of new cells in the process of growth.
From Wikipedia
4.2 What Shapes an Ecosystem?
• Factors
– Living/biological
• Biotic
– What the org eats
– Amt of food available
– What eats the org.
– Nonliving/physical
• Abiotic
– Temperature
– Climate
– Shelter
4.2 What Shapes an Ecosystem?
• Niche
– Physical & biological (abiotic & biotic)
conditions as well as how it responds
to/uses the conditions
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Diet
Predators
How it hunts/gathers food
Living conditions
When/how reproduce
How develop (grow up)
4.2 community interactions
• Competition
– 2 orgs use same resource at same time
any necessity of life
– Try to occupy similar niche
– Competitive exclusion principle
• No 2 species can occupy same niche
• Predation
– Predator/pray
4.2 community interactions
• Symbiosis
– 2 species live closely together
• Mutualism
– Both species benefit
• Commensalism
– One species benefits, the other is neither helped nor
harmed
• Parasitism
– One species benefits, the other is harmed
4.2 Ecological Succession
• Disturbance causes destruction of env.
and species die-off
• Primary
– On land where there is no soil/organic matter,
ie bare rock
– Pioneer species
• 1st species into a desolate area
• Secondary
– Organic material still present
5.1 How Populations Grow
• Geographic distribution
– aka range
– Area where a population lives
• Population density
– Number of individuals per unit of area
• Ex: as of 2000, Concord pop. = 121,780
Inds/area = 121,780 ppl/Concord
• Growth rate
– Rate that # of inds. grows w/in a pop.
5.1 How Populations Grow
• Growth rate
– Population growth
• Births
• Deaths
• # inds. leave/come to an area
(emigration/immigration)
5.1 How Populations Grow
• Exponential growth
– Unlimited resources
– Compare graphs on pg 121
• How are these graphs alike?
• Besides showing dif. orgs., how are they
graphs different?
• What do these differences tell you
about the different species?
• What is another difference btw how
elephants and bacteria reproduce?
5.1 How Populations Grow
• Logistic growth
– Growth slows/stops
– Carrying capacity
• Limit of inds that can live in a given area based
on the available resources
5.2 Limits to Growth
• Limiting factors
– Density-dependent
• Competition, predation, parasitism, disease
– Density-independent
• Abnormal weather, natural disasters, season
cycles, human activity
5.3 Human Population Growth
• Exponential (graph pg 129)
• Note historical events
• Factors that effect human population
growth: war, famine, disease,
social/economic
• Age structure diagrams (pg 131)
Sub work 10/17
• Due at end of period
– Pg 118 Inquiry Activity
– Pg 123 Analyzing Data
• Due on test day
•Write on sep. sheet of loose
leaf paper
•Name, date, period upper left
corner
•Name of assignment top line
right corner
•Grade: neatness &
completeness
– Workbook 5.1, 5.2, 5.3 (due test day)
• Test Thursday
Test Review
• How to study:
– Keep up with reading HW & do workbook
• If no workbook, answer end of section questions and
any other questions provided in the text
– Keep a vocab. list/make flash cards
– Read & understand any pictures, tables, charts,
or graphs
– Go back through text & notes looking for
key/repeated concepts or topics
– As you review, jot down any questions or topics
that are still unclear
Test Review – Main Topics
• Vocabulary
– 3.1 (pg 63)
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Ecology
Biosphere
Species
Population
Community
Ecosystem
biome
– 3.2 (pg 67)
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Autotroph/producer
Photosynthesis
Chemosynthesis
Heterotroph/consumer
Herbivore
Carnivore
Omnivore
Detritivore
Decomposer
Food chain
Food web
Trophic level
Ecological pyramid
biomass
Test Review – Main Topics
• Vocabulary
– 3.3 (pg 74)
• None
– Concepts
• Energy flows  linear
• Matter cycles
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Carbon
Phosphorus
Nitrogen
Water
» Evap./transp.
» Condensation
» Precipitation
– 4.2 (pg 90)
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Biotic factor
Abiotic factor
Habitat
Niche
Resource
Comp. exclude. princ.
Predation
Symbiosis
Mutualism
Commensalism
Parasitism
Ecological succession
Primary succession
Pioneer species
Secondary succession
Test Review – Main Topics
• Vocabulary
– 5.1 (pg 119)
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Population density
Immigration
Emigration
Exponential growth
Logistic growth
Carrying capacity
– 5.2 (pg 124)
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Limiting factor
Density-dependent
Density-independent
Predator-pray
relationship
– 5.3 (pg 129)
• Demography
• Demographic transition
• Age-structure diagram