I. Scientific Method: Step by step method
used to solve problems
A. Observations
• Facts- Things known to be true
• Questions- Solve a problem
B. Hypothesis
• “educated guess”
• Statement about the problem
C. Experimentation
1. Reproducible- same results to be obtained
by others
2. Controlled experiment- control
comparison group experimental group
a) Experimental group- variable- one
condition which is changed
b) Control group- all factors the same
c) Double blind study- test subjects &
administrations don’t know who is the
(exp. group, control group)
Data- numerical observations (analyze)
D. Conclusions
• Support or don’t support the hypothesis
E. Theories
• Hypothesis that has withstood the test of
time
II. Biology
A. Organization
1. Atoms- smallest particle of matter
2. Molecules- two or more atoms combined
3. Organelles- small functional parts of cells
(ex. Ribosomes)
4. Cell- basic unit of life
5. Tissue- group of similar cells (muscle)
6. Organ- group of similar tissues that
perform a certain function (liver)
7. Systems- group of organs performing
specific functions
8. Organism- living thing
9. Species- interbreeding group of organisms
10. Population- group of same species in a given
area
11. Community- group of populations “living
things” in a given area
12. Ecosystem: interaction of a community and its
surroundings
13. Biosphere- living portion of earth, contains
biomes “major climate zones”
B. Homeostasis
• Ability to maintain a constant
internal state
a) Endotherms- warm
blooded
b) Ectotherms- cold blooded
I. Ecology: Study of “house” environment
A. Populations •
•
•
Size – number of individuals
Density – number of individuals per certain
area
Distribution – location within the area
II. Population Growth
A. Exponential growth
1. J-shaped
2. Intrinsic rate – rate of growth
3. Birth and death rate – determine population
growth
4. Zero population rate – births = deaths
B. Logistic growth
1. S-shaped
2. Equilibrium – population stays fairly constant
C. Carrying capacity
1. Maximum population density that an area can
support
2. Environmental resistance – factors which limit
population growth
D. Population growth in nature
1. K-selected species – density dependent,
population size limited by carrying capacity
2. R-selected species – opportunistic species,
population size limited by reproductive rate
III.
Limiting Factors
A. Density-independent factors
1. Environmental changes
2. Natural disasters
B. Density-dependent factors
1. Competition – trying for same resources
a.) intraspecific – same species
b.) interspecific – between different species
2. Predation
a.) predator – prey oscillations
3. Parasitism – prey up,
parasites up
4. Emigration / Immigration
(leave / move into)
5. Disease
a.) population up, disease up
6. Cannibalism – eating of own
species
Survivorship Curves
1. Type I – late loss
2. Type II – constant loss
3. Type III – early loss
K
R
IV.Demography
A. Population age structure
1. Age distribution – 5 years (0-4, 5-9)
2. Mortality and survivorship – death rates
and ages
3. Fertility – birth rate
4. Age structure and population growth histograms
IV. Human Population Growth
A. Rate 179 per minute
94 million per year
• 1800 – 1 billion
• 1930 – 2 billion
• 1960 – 3 billion
• 1975 – 4 billion
• 1987 – 5 billion
• 1999 – 6 billion
• Malthusian doctrine- 1798 as population
increases so do problems. Food supply would run
out for humans- Rat experiment
B. Future? Carrying capacity? 11 billion
• 7 billion (2012 / 2008) 8 billion(2026/2019)
C. Controls
• Disease – resources - pollution
Chapter 27
Community
Interactions
I. Ecological Communities
A. Biodiversity – how many different species
1. Ecological dominants – certain species
are more common
2. Keystone species – species that entire
community depends on
3. Trophic cascade- keystone species
affects all other populations within the
ecosystem
4. Nonindigenous species – species not
native (examples: Brown tree snake)
B. Habitat – environment organism lives in
C. Niche – “role”
• What is the organisms occupation
producers, consumers, decomposers
Trophic level
II. Symbiosis – coevolution “living together”
A. Competition - 1. Trying for the same resources
2. Resource partitioning – live in specific area
eat specific organisms
3. Competitive exclusion principle – 2
populations compete for the same limited
resources, one will always out compete
B. Predation + - •
•
•
Predator eats and kills prey
Mimicry – look similar to another
species which is usually poisonous
preventing being preyed upon
Camouflage- blend in to avoid detection
C. Parasitism + 1. Host – fed upon
2. Parasite – feeds & lives on
host (usually not killed)
D. Mutualism + + both organisms benefit
Bees and flowers, rhino and oxpecker bird
lichen is algae and fungus together
E.Commensalism + 0 one benefits one unaffected
1. Host – unaffected
2. Commensal – benefits
predators and scavengers
epiphytes : plants w/roots in air
orchids, bromelaids
sharks and remoras
III.Succession – predictable change within a
community over time
Primary succession
B. Secondary Succession
• Interrupted succession natural disaster or
man-made
• Will go back to climax community
• Quicker than primary succession
2. Water Succesion
a)
b)
c)
d)
e)
Lake – clear water
Pond – submergent vegetation
Marsh – emergent vegetation – humus
Bog – vegetation mat over water
Forest Water fills in over time with dead
decaying material(humus) which creates less
water and more land
I. Biotic Factors “Living Factors”
A. Autotrophs (Producers) – Plants, “self
feeders” can make their own food
1. Photosynthesis – light energy  food
energy
2. Chlorophyll – green pigment
3. CO2 + H2O  C6H12O6 (glucose)+ O2
Light is necessary
4. Provide food for the entire ecosystem
5. Are green and sessile
“Other Feeders”
B. Heterotrophs (consumers) – can not make
their own food
1. Cellular respiration – process by which food
is converted to energy (food  energy)
2. C6H12O6 + O2  CO2 + H2O + ATP (high
energy molecule)
3. Animals
4. Herbivores – eat plants
a.) primary consumers – first in food chain
b.) leaf eaters, seeds, fruit, and berry
5. Carnivores – meat eaters
6. Omnivores – both plant and meat
7. Saprophytes – non green plant
(fungi) feed on dead and decaying
material
8. Other feeding techniques
a.) liquid feeders – blood & nectar
b.) waste feeders – scavengers (eat
what they didn’t kill)
detritivores – eat wastes
C. Decomposers
•
•
“bacteria” break down organic material into it’s
simplest form elements
C, H, O, N carbon, hydrogen, oxygen, nitrogen
II. Food Chains
•
•
Passage of energy through an ecosystem
Producer  1st  2nd  top
Owl Pellets
A. Trophic Levels
1. Producer
2. 1st order consumer
3. 2nd order consumer (secondary)
4. 3rd order consumer (tiertiary) – or top order
B. Ecological Pyramids – rule of 10
1. Numbers – producers base
2. Energy – most energy to
producers, energy is lost
thru a food chain
3. Biomass – total amount
of living material
C. Food Webs all possible feeding relationships in an area
III. Ecosystems – community and it’s
environment
A. Abiotic factors – (nonliving factors)
1.
2.
3.
4.
5.
Air – aerobic (need O2) anaerobic (do not need
O2)
Sunlight – warmth, photosynthesis, vitamin D,
sight
Temperature – climate (average) weather (day
by day)
Soil – nutrients (humus), minerals, soil type
Water – amount, type (salinity) (brackish)
IV. CYCLES
A. Carbon cycle
1. respiration CO2 photosynthesis, fossil fuels
2. Carbon decay
• Living things C
forms chains of carbon
B. Nitrogen Cycle
78% of air is N2
NO3 Nitrates – plants use
1. Ammonification – dead decaying
organisms, feces & urine – “protein” broken
by bacteriaammonia
2. Nitrification – nitrifying bacteria–
ammonia(NH4)nitrates( NO3)
3. Dentrification – denitrifying bacteria
nitrates  N2
4. Nitrogen fixation – N2 (air) Nitrates,
legumes have nitrogen fixing bacteria in their
roots
C. Water Cycle
a) Respiration “animals” release water
b) Transpiration “plants” release water
c) Evaporation “water”
d) Water rises as a gas, condenses into liquid
Falls to earth as precipitation
e) Ground water in Aquifers – underground
lakes
f) Human use – irrigation, industry, daily
needs- all put pollutants back in water
V. Current Environmental Problems
A. Water Pollution
1. Industrial – chemicals, 50% of all
water usage, 23 million septic tanks,
190,000 lagoons 9,000 landfills
2. Surface – runoff, point and nonpoint
3. Groundwater – High Plains aquifer –
20% of all cropland, 200 hazardous
chemicals
4. Residential sewage – sewage
treatment, primary, secondary, tertiary
Most US large cities have secondary plants
B. Air Pollution
- CO, CO2 (38%)
- NO2 (9%)
- SO2 (8%) - Particulates (36%)
-VOC’s volatile organic compounds (9%)
1. Smog – suspended particles
photochemical –yellow / brown, thermal inversions,
sunlight + NO2
industrial - grey, dust soot & ash
2. Ozone layer – layer of O3 filters out UV
rays, 1995 hole in ozone layer over the
Antarctic, CFC’s destroy O3 molecule
3. Acid rain pH 3.5 –5.5 normal rain pH 6-7,
burning of fossil fuels, sulfur dioxide
combines with water (sulfuric acid)
nitrous oxide combines with water (nitric
acid)
4. Greenhouse effect – global warming,
particulates + CO2 trap in heat, burning of
fossil fuels, destruction of forests
C. Agriculture
a) monoculture – one crop
b) chemical fertilizers – nitrates
c) irrigation – depletes ground water
d) soil erosion – loss of top soil
D. Biological Magnification, pesticide and
heavy metal amounts increase thru a food
chain- increase in the parts per million
pesticides – stored in fat
Chapter 29
Earth’s
Diverse
Ecosystems
I. Biomes – major climatic regions
A. Terrestrial- land
1. Tundra – permafrost “lichen”
2. Taiga – coniferous forest evergreens
3. Temperate forest – deciduous forest maple and
oaks
4. Desert – little rain, extreme temps, 32-99
degrees F, cactus
5. Grassland – reduced rainfall, grasses, savannahs
6. Tropical rain forest – high rainfall, high temps,
equator, 5 layers, “epiphytes”
B. Aquatic
1. Freshwater
a.) littoral – near shore
b.) photic or limnetic – light, limnetic
c.) profundal – bottom, low light
oligotrophic – clear lakes, streams, spring fed, little
pollution, constant water
Eutrophic – increased “humus”, vegetation, sewage,
high pollution
2. Estuaries – brackish waters – high in nutrients,
salt and fresh water
3. Salt marshes / Mangroves – border oceans,
salt tolerant plants and animals
Sonneratia tree proboscis monkey
Mudskippers epiphytes
4. Intertidal – pockets of water
organisms exposed to air
5. Kelp forests – giant algae
6. Coral reefs – breeding grounds for fish
7. Open sea – plankton (base of food chain,
rain)
II. Habitat Destruction
A. Deforestation – removal of trees for
lumber, biofuels, slash/burn agriculture
Losing 42 million acres per year
40% of worlds rain forests are gone
B. Desertification – grasslands 
desert like, irrigation
Chapter 30
Conserving
Earth’s
Biodiversity
What Is Biodiversity?
• Biodiversity refers to the variety of living
organisms on the planet, including their
genes, ecosystems, and community
interactions
I. Humans and the environment
A. Human population growth
- exponential, more resources used, more
pollution, more habitat destruction
B. Industrialization
- chemicals, radiation, thermal, synthetics
C. Economic growth
- money vs. ecology
D. Agriculture – unsustainable versus
sustainable
- monoculture, increased yield,
erosion, pesticides, herbicides
II. Energy
A. Nonrenewable Energy
1) fossil fuels – hydrocarbons( gas, coal, oil)
produce CO, CO2, SO2, NO2, and particulates
2) Nuclear power – fission, radioactive wastes,
thermal pollution
B. Renewable Energy
•
•
•
•
•
•
Wind
Hydroelectric
Solar
Trees
Garbage – burning
Nuclear fusion
Extinction
• Most biologists believe that human activities
are now causing a sixth mass extinction
• The current extinction rate is 100 to 1000
times the background rate predicted in the
absence of people
Many species may have become extinct before being discovered, as
suggested by two newly described species
The Australian snubnose dolphin and the Aftrican kipunji
monkey
Only about 1000 of each remain
Both are threatened by human activity and might have become
extinct before discovery
Threatened Species
• Increasing numbers of species are threatened
with extinction
• Depending on the likelihood of extinction in
the near future, threatened species are
described as critically endangered,
endangered, or vulnerable
As of 2004 there are 15,589 threatened species
12% of all birds
23% of all mammals
32% of all amphibians
42% of all turtles and tortoises
Threats to Biodiversity
• Two processes are fueling the decline in
Earth’s biodiversity
– Increasing use of resources to support human
lifestyles
– Human activities that destroy habitats and pollute
the environment
Humans threaten biodiversity in a number of ways
Habitat destruction
Overexploitation
Harmful interaction with invasive species
Pollution
Global warming
Habitat Destruction
• Other activities that lead to habitat
destruction
– Damming rivers
– Draining wetlands
– Building roads and housing
– Industry
Some species need thousands of acres to find food and
breed
Habitat fragmentation threatens wildlife by splitting up
natural ecosystems
Invasive Species
• When non-native species are introduced into
an area, they can becomes invasive
• Invasive species can displace native species
and disrupt community interactions through
– Competion for food and/or habitat
– Direct predation
Island and lake communities are particularly vulnerable to
invasive species
The mongoose, imported to Hawaii to control rats, now
threatens birds
The Nile perch, introduced to Lake Victoria for fishing, now
threatens 200 other species
Pollution
• Pollutants that threaten biodiversity include
synthetic chemicals
– Plasticizers, flame retardants, pesticides
• Enter air, water, soil
• Accumulate in animal tissues, disrupting
development or reproduction
Accumulation of high levels of some natural substances
are also threats
Mercury, lead, and arsenic from mining and
manufacturing are toxic
Oxidized nitrogen and sulfur released by burning fossil
fuels lead to acid rain
Global Warming
• Leads to habitat destruction
• Rapid pace of global warming taxes abilities of
species to adapt to changing conditions
through natural selection
• By 2050: estimated that 1 million species will
be threatened with extinction due to global
warming
Human Population Growth
• 75-80 million people are added to the planet
every year
• Growth rate is incompatible with a sustainable
increase in quality of life for the present 6.5
billion inhabitants
Lifestyle and Technologies
• Changes that humans can make to develop
sustainable approaches
– Make responsible reproductive choices
– Reduce energy consumption and use of fossil fuels
– Develop and use energy-saving technologies
– Rely on renewable energy sources
– Make consumer choices that promote sustainable
practices