Download Document

SUSTAINING THE
MILLER/SPOOLMAN
EARTH | G. TYLER MILLER | SCOTT E. SPOOLMAN
11e
2
Science, Matter,
Energy,
and Systems
© Cengage Learning 2015
2-1 What Do Scientists Do?
• Science is a search for order in nature
– The scientific method
• Identify a problem
• Find out what is known about the problem
• Ask a question to investigate
• Collect data to answer the question
• Propose a scientific hypothesis
© Cengage Learning 2015
Science Is a Search for Order in Nature
(cont’d.)
• The scientific method (cont’d.)
– Make testable projections
– Test the projections with further experiments,
models, or observations
– Accept or reject the hypothesis
• Scientific theory: well-tested and widely
accepted hypothesis
• Scientific law (law of nature)
© Cengage Learning 2015
The Results of Science Can Be Tentative,
Reliable, or Unreliable
• Tentative science (frontier science)
• Reliable science
– Scientific consensus
• Unreliable science
© Cengage Learning 2015
Science Has Some Limitations
• Scientists cannot prove or disprove
anything absolutely
• Scientists are not totally bias free
• Many natural world systems involve a
huge number of variables with complex
interactions
• Statistical methods are necessary when
direct measures are not possible
© Cengage Learning 2015
Science Focus: Statistics and Probability
• Statistics
– Collect, organize, and interpret numerical data
• Probability
– The chance that something will happen or be
valid
– Need large enough sample size
© Cengage Learning 2015
2-2 What Is Matter and What Happens
When It Undergoes Change?
• Matter consists of elements and
compounds
– Matter: has mass and takes up space
– Elements: fundamental type of matter
• Cannot be broken down chemically into other
substances
– Compounds: two or more different elements
bonded together in fixed proportions
© Cengage Learning 2015
Matter Consists of Elements and
Compounds (cont’d.)
– Matter
• Has mass and takes up space
– Elements
• Unique properties
• Cannot be broken down chemically into other
substances
– Compounds
• Two or more different elements bonded together in
fixed proportions
© Cengage Learning 2015
Atoms, Molecules, and Ions Are the
Building Blocks of Matter
• Atomic theory: all elements are made of
atoms
• Subatomic particles
– Neutrons: no electrical charge
– Protons: positive electrical charge
– Electrons: negative electrical charge
• Atom
– Nucleus and an electron probability cloud
© Cengage Learning 2015
Atoms, Molecules, and Ions Are the
Building Blocks of Matter (cont’d.)
• Atomic number
– Number of protons in the atom’s nucleus
• Mass number
– Total number of neutrons and protons in the
atom’s nucleus
• Isotopes
– Forms of an element having the same atomic
number but different mass numbers
© Cengage Learning 2015
Atoms, Molecules, and Ions Are the
Building Blocks of Matter (cont’d.)
• Molecule
– Two or more atoms of the same or different
elements held together by chemical bonds
• Ions
– An atom or a group of atoms with one or more
net positive or negative electrical charges
• pH
– Measure of acidity based on comparative
amounts of H+ and OH© Cengage Learning 2015
Organic Compounds Are the Chemicals
of Life
• Organic compounds
– Hydrocarbons
– Chlorinated hydrocarbons
– Simple carbohydrates (simple sugars)
– Macromolecules: complex organic molecules
• Major types of organic polymers: complex
carbohydrates, proteins, and nucleic acids
• Lipids
• Inorganic compounds
© Cengage Learning 2015
Matter Comes to Life through Genes,
Chromosomes, and Cells
• Genes: certain sequences of nucleotides
– Traits
• Chromosome: consists of thousands of
genes
• Cells: fundamental units of life
© Cengage Learning 2015
A human body contains trillions
of cells, each with an identical set
of genes.
Each human cell (except for red
blood cells) contains a nucleus.
Each cell nucleus has an identical set
of chromosomes, which are found in
pairs.
A specific pair of chromosomes
contains one chromosome from each
parent.
Each chromosome contains a long
DNA molecule in the form of a coiled
double helix.
Stepped Art
Fig. 2-4
Genes are segments of DNA on
chromosomes that contain instructions
to make proteins—the building blocks
of life.
Some Forms of Matter Are More
Useful than Others
• Matter quality
– High-quality matter
• Highly concentrated
• Near earth’s surface
• High potential as a resource
– Low-quality matter
• Not highly concentrated
• Deep underground or widely dispersed
• Low potential as a resource
© Cengage Learning 2015
Matter Can Undergo Change but Cannot
Be Created or Destroyed
• Physical change
– No change in chemical composition
• Chemical change (chemical reaction)
– Change in chemical composition
– Reactants and products
• Law of conservation of matter
© Cengage Learning 2015
2-3 What is Energy and What Happens
When It Undergoes Change?
• Energy comes in many forms and some
are more useful than others
– Kinetic energy
• Energy associated with motion
• Heat
• Electromagnetic radiation
– Potential energy: stored energy
• Can be changed into kinetic energy
© Cengage Learning 2015
Visible light
Shorter
wavelengths Gamma
rays
and higher
energy
Wavelengths
(not to scale)
Fig. 2-6
X rays
Nanometers
UV
radiation
Infrared
TV, Radio
radiation Microwaves waves
Micrometers
Centimeters
Meters
Longer
wavelengths
and lower
energy
Energy Comes in Many Forms (cont’d.)
• Solar energy principle of sustainability
• Energy quality
– High-quality energy
• Concentrated
• Great capacity to do useful work
– Low-quality energy
• Dispersed
• Little capacity to do useful work
© Cengage Learning 2015
Energy Changes Are Governed by Two
Scientific Laws
• First law of thermodynamics (law of
conservation of energy)
– Energy is neither created nor destroyed in
physical and chemical changes
• Second law of thermodynamics
– When energy is changed from one form to
another, it always goes from a more useful to
a less useful form
© Cengage Learning 2015
2-4 What Keeps Us and Other
Organisms Alive?
• Ecology is the study of connections in
nature
– Organism: any form of life
– Species: set organisms
• Resemble one another in appearance, behavior,
chemistry, and genetic makeup
© Cengage Learning 2015
Science Focus: Have You Thanked the
Insects Today?
• Insects’ vital roles in helping to sustain life
on earth
– Pollinating
– Eating other insects
• Helping control pests
– Loosening and renewing the soil
© Cengage Learning 2015
Life Is Organized Within Populations,
Communities, and Ecosystems
– Population
• Genetic diversity
• Habitat
– Biological community (community)
– Ecosystem
– Biosphere
© Cengage Learning 2015
Biosphere
Parts of the earth's air, water, and soil
where life is found
Ecosystem
A community of different species
interacting with one another and with
their nonliving environment of matter
and energy
Community
Populations of different species
living in a particular place, and
potentially interacting with each
other
Population
A group of individuals of the same
species living in a particular place
Organism
An individual living being
Cell
The fundamental structural and
functional unit of life
Molecule
Chemical combination of two or
more atoms of the same or different
elements
Atom
Smallest unit of a chemical element
that exhibits its chemical properties
Water
Stepped Art
Fig. 2-8
Hydrogen
Oxygen
Earth’s Life-Support System Has Four
Major Components
• Atmosphere
– Troposphere: inner layer
– Stratosphere: contains ozone layer
• Hydrosphere
• Geosphere
• Biosphere
– Biomes
– Aquatic life zones
© Cengage Learning 2015
Atmosphere
Biosphere
(living organisms)
Soil
Rock
Crust
Mantle
Geosphere
(crust, mantle, core)
Mantle
Core
Atmosphere
(air)
Hydrosphere
(water)
Fig. 2-9
Three Factors Sustain the Earth’s Life
• One-way flow of high-quality energy
– Two laws of thermodynamics
• Cycling of nutrients through parts of the
biosphere
– Fixed supply
• Gravity holds earths atmosphere
© Cengage Learning 2015
Sun, Earth, Life, and Climate
• Sun’s energy
– Reaches the earth as electromagnetic waves
• UV radiation, visible light, and heat
– Absorbed or reflected back into space by the
earth’s atmosphere and surface
• Natural greenhouse effect
© Cengage Learning 2015
2-5 What Are the Major Components
of an Ecosystem?
• Ecosystems have living and nonliving
components
– Biotic: living components
– Abiotic: nonliving components
• Range of tolerance
– Optimum level or range
• Limiting factor principle
– Impact of too much/little of any abiotic factor
© Cengage Learning 2015
Oxygen (O2)
Precipitation
Carbon dioxide (CO2)
Producer
Secondary
consumer
(fox)
Primary
consumer
(rabbit)
Producers
Water
Fig. 2-11
Decomposers
Soluble mineral
nutrients
Producers and Consumers Are the Living
Components of Ecosystems
• Producers (autotrophs)
– Photosynthesis:
• CO2 + H2O + solar energy → glucose + oxygen
• Consumers (heterotrophs)
– Primary consumers (herbivores)
– Secondary consumers
– Tertiary (higher) consumers
– Omnivores
© Cengage Learning 2015
Producers and Consumers Are the Living
Components of Ecosystems (cont’d.)
• Decomposers
– Consumers that release nutrients
– Bacteria and fungi
• Detritus feeders (detritivores)
– Feed on dead bodies of other organisms
– Earthworms, some insects, and vultures
• Aerobic respiration
– glucose + oxygen → CO2 + H2O + energy
© Cengage Learning 2015
Decomposers
Detritus feeders
Bark beetle
engraving
Long-horned
beetle holes
Carpenter
ant galleries
Termite
and carpenter
ant work
Dry rot
fungus
Wood
reduced Mushroom
to powder
Time
progression
Fig. 2-13
Powder broken down by
decomposers into plant
nutrients in soil
Heat
Chemical nutrients
(carbon dioxide,
oxygen, nitrogen,
minerals)
Heat
Heat
Producers
(plants)
Decomposers
(bacteria, fungi)
Heat
Fig. 2-14
Solar
energy
Consumers (plant
eaters, meat
eaters)
Heat
Science Focus: Many of the World’s Most
Important Species Are Invisible to Us
• Microbes (microorganisms)
– Bacteria
– Protozoa
– Fungi
– Floating phytoplankton
© Cengage Learning 2015
Natural Systems Have Tipping Points
• Threshold level (ecological tipping point)
• Tipping points currently being faced
– Collapse of certain populations of fish
• Overfishing
– Premature extinction of thousands of species
• Overhunting and habitat destruction
– Long-term climate disruption
• Gas emissions
© Cengage Learning 2015
2-6 What Happens to Energy in an
Ecosystem?
• Energy flows through ecosystems in food
chains and food webs
– Food chain
• Movement of energy and nutrients from one
trophic level to the next
• Photosynthesis → feeding → decomposition
– Food web
• Network of interconnected food chains
© Cengage Learning 2015
First Trophic
Level
Second Trophic
Level
Third Trophic
Level
Fourth Trophic
Level
Producers
(plants)
Primary
consumers
(herbivores)
Secondary
consumers
(carnivores)
Tertiary
consumers
(top carnivores)
Heat
Heat
Heat
Heat
Solar
energy
Heat
Heat
Heat
Decomposers and detritus feeders
Fig. 2-16
Humans
Sperm whale
Blue whale
Elephant seal
Crabeater
seal
Adelie
penguin
Killer
whale
Leopard
seal
Emperor
penguin
Petrel
Squid
Fish
Carnivorous
zooplankton
Krill
Fig. 2-17
Herbivorous
zooplankton
Phytoplankton
Usable Energy Decreases with Each Link
in a Food Chain or Web
• Biomass
– Dry weight of all organic matter of a given
trophic level in a food chain or food web
– Decreases at each higher trophic level due to
heat loss
• Ecological efficiency
– Pyramid of energy flow
• Ninety percent energy loss with each transfer
• Less chemical energy at higher trophic levels
© Cengage Learning 2015
Usable energy available
at each trophic level
(in kilocalories)
Tertiary
consumers
(human)
10
Secondary
consumers
(perch)
100
Primary
consumers
(zooplankton)
Heat
Heat
1,000
Heat
10,000
Producers
(phytoplankton)
Stepped Art
Fig. 2-18
Heat
Decomposers
Heat
Some Ecosystems Produce Plant Matter
Faster Than Others Do
• Gross primary productivity (GPP)
– Conversion rate of solar energy to chemical
energy
• Net primary productivity (NPP)
– Measure of how fast producers can make the
chemical energy that is stored in their tissues
• Ecosystems and life zones differ in their NPP
© Cengage Learning 2015
Fig. 2-19
2-7 What Happens to Matter in
an Ecosystem?
• Nutrients cycle in the biosphere
– Biogeochemical cycles (nutrient cycles)
– Cycles
• Driven directly or indirectly by incoming solar
energy and the earth’s gravity
• Include hydrologic (water), carbon, nitrogen,
phosphorus, and sulfur cycles
© Cengage Learning 2015
The Water Cycle
• Major processes
– Evaporation
– Precipitation
– Transpiration
• Natural renewal of water quality
© Cengage Learning 2015
Human Activities Have Major Effects on
the Water Cycle
• Withdrawing large amounts of freshwater
at rates faster than nature can replace it
• Clearing vegetation
– Increases runoff and reduces amount of water
seeping into the ground
• Draining wetlands
– Increases flooding
© Cengage Learning 2015
Condensation
Ice and
snow
Condensation
Transpiration
from plants
Precipitation
to land
Evaporation of
surface water
Runof
f
Lakes and
reservoirs
Infiltration and
percolation
into aquifer
Groundwater
in aquifers
Evaporation
from ocean
Runoff
Increased runoff on land
covered with crops,
buildings and pavement
Runoff
Overpumping
of aquifers
Runoff
Increased runoff
from cutting
forests and filling
wetlands
Water pollution
Ocean
Natural process
Natural reservoir
Human impacts
Natural pathway
Fig. 2-20
Pathway affected by
human activities
Precipitation
to ocean
The Carbon Cycle
• Link between photosynthesis in producers
and aerobic respiration in producers,
consumers, and decomposers
– Circulates carbon in the biosphere
© Cengage Learning 2015
Carbon
dioxide in
atmosphere
Respiration
Photosynthesis
Animals
(consumers)
Diffusion
Burning
fossil fuels
Forest fires
Plants (producers)
Deforestation
Transportation
Carbon dioxide
dissolved in ocean
Marine food webs
Producers,
consumers,
decomposers
Carbon
in limestone or
dolomite
sediments
Fig. 2-21
Process
Reservoir
Pathway affected by
humans
Natural pathway
Respiration
Carbon in
animals
(consumers)
Carbon in
plants
(producers)
Decomposition
Compaction
Carbon in
fossil fuels
Human Activities Affect the Carbon Cycle
• Additional CO2 added to the atmosphere
– Tree clearing
– Burning of fossil fuels
• Increased atmospheric CO2 and other
greenhouse gases
– Could lead to climate disruption
© Cengage Learning 2015
The Nitrogen Cycle: Bacteria in Action
• Nitrogen-fixing
– Lightning
– Nitrogen-fixing bacteria
• Major parts of the cycle
– Nitrogen fixation
– Nitrification
– Ammonification
– Denitrification
© Cengage Learning 2015
Human Activities Affect the Nitrogen Cycle
• Burning fossil fuels
– Acid rain
• Adding N2O to the atmosphere through
– Bacteria acting on fertilizers and manure
• Destroying forests, grasslands, and
wetlands
– Releases stored nitrogen
© Cengage Learning 2015
Human Activities Affect the Nitrogen Cycle
(cont’d.)
• Increasing nitrates in bodies of water
– Agricultural runoff and sewage discharges
• Removing nitrogen from topsoil
– Harvesting crops and clearing grasslands and
forests
© Cengage Learning 2015
The Phosphorus Cycle and Human
Interference with It
• Cycles through water, the earth’s crust,
and living organisms
• Limiting factor for plant growth
• Impact of human activities
– Removing large amounts of phosphate from
the earth to make fertilizers and detergents
– Clearing tropical forests
– Erosion leaches phosphates into streams
© Cengage Learning 2015
Process
Reservoir
Pathway affected by humans
Natural pathway
Phosphates
in sewage
Phosphates in
mining waste
Phosphates
in fertilizer
Runoff
Runoff
Sea
birds
Runoff
Erosion
Animals
(consumers)
Phosphate
dissolved
in water
Plants
(producers)
Bacteria
Fig. 2-23
Plate
tectonics
Phosphate in
rock (fossil
bones, guano)
Phosphate
in shallow
ocean
sediments
Ocean
food webs
Phosphate
in deep
ocean
sediments
Earth’s Rocks Are Recycled Very Slowly
• Igneous rock
– Form below or at earth’s surface from molten
material
• Sedimentary rock
– Created from sediments under pressure
• Metamorphic rock
– Existing rocks subjected to high temperatures,
high pressures, and/or chemically active fluids
© Cengage Learning 2015
Three Big Ideas
• According to the law of conservation of
matter, no atoms are created or destroyed
whenever matter undergoes a physical or
chemical change.
© Cengage Learning 2015
Three Big Ideas (cont’d.)
• According to the laws of thermodynamics,
whenever energy is converted from one
form to another in a physical or chemical
change, no energy is created or
destroyed, and we always end up with
lower-quality or less usable energy than
we started with.
© Cengage Learning 2015
Three Big Ideas (cont’d.)
• Life is sustained by the flow of energy from
the sun through the biosphere, the cycling
of nutrients within the biosphere, and
gravity.
© Cengage Learning 2015
The second law of thermodynamics holds, I think,
the supreme position among laws of nature. . . .
If your theory is found to be against the second law
of thermodynamics, I can give you no hope.
Henry David Thoreau
© Cengage Learning 2015