Transcript Bio 1 Chap1-2 2008 for posting

.

Study of life
Chapter 1 Biology: The Study of
Life
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
Characteristics of Life
Scientific Methodology

Investigate:
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Interdependencies between organisms
Interactions with environment: biotic and abiotic
factors
1.1 Why Study Biology?
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Understand our world
Make it better
Advance medicine
Protect its future
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TROPICAL RAIN FORESTS
Despite covering only 6% of our
planet's surface……

………over half of the earth's animal,
insect species, and flora live there.
FACTS
1.) Once covered 14% of the world but now
cover a mere 6%!
2.) One and a half acres of the rainforest are
destroyed each second!
3.) We lose 137 plants, animal and insect
species/day. About 50,000/yr!
25 % of modern medicines
originate here.

The leaves of this plant ,
foxglove, contain
digitalis, a substance used
to treat heart problems.
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4). 1 out of every 4 ingredients in our medicines is
from the rainforest.
For example, more than 70 percent of the plants
known to produce compounds with anticancerous properties live in rainforests
They regulate
our climate.
How Do You Study
Life?

Study interactions—
 Biotic and abiotic
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Honeybees, flowers, pollination,plant
reproduces, provides oxygen, provides
food
CHARACTERISTICS OF
LIVING THINGS (Organism)
1. Cell (s)
2. Displays Organization
3. Grows & Develops
4. Reproduces
5. Responds to Stimuli
6. Requires Energy
7. Maintains homeostasis
8. Adaptations evolve over time
1. Cells
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Basic unit of life
One or more
2. Displays Organization

Atoms to molecules to organelles to cells to
organs to organ systems to organism

Each organized structure has specific function
Fig. 1.5a, p. 6
(see next slide)
(see previous slide)
Fig. 1.5b, p. 6
3. Grows and Develops
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Growth: add mass
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More cells & new structures.
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Organisms increase in size and
complexity
Development: all the changes throughout a
lifetime.

.
such as a HUMMINGBIRD…
…..
Almost ready to hatch!!
Growing…growing…
4. Reproduces
Pass traits to offspring
Continuation of
the species
Species__________
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Organisms reproduce their own kind.
5. Respond to Stimuli
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Stimulus:
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Causes some reaction
external or internal
Response
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Reaction to a stimulus
The speed of the response may be “fast” or
“slow”.
Even bacteria sense and respond.

6. Requires Energy
Required for all life processes
Organisms are “open” systems, they must
continually take in energy.
7.Maintains Homeostasis
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“homeo” = same
“stasis” =state
Maintain stable internal environment\within
tolerable limits.
8. Adaptations Evolve over time
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Inherited changes
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Occur over time
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Help species survive
1.2 The Nature of Science
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Theory:
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Explanation of a natural phenomenon
Supported by many experiments and observations
Pseudoscience: not science-based
1.3 methods of Science
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Scientific Method
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Logical, objective approach to investigating a
problem, or attempt to explain observations.
Forming a hypothesis
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Hypothesis: A testable explanation of a
situation
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Serendipity: the occurrence of unexpexted,
but fortunate results
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Penicillin
Post-it-notes
Collect the Data
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Experiment
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Controlled setting
Testing of a hypothesis
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1. Controlled Experiments
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A) Control Group: basis of comparison
B) Experimental Group: exposed to factor being
tested.
2. Experimental Design
Only one factor can be changed at a time
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A) Independent Variable:
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B) Dependent Variable:
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The tested factor
What is measured (measures the effect of the
Independent variable).
C) Constant: factor (s) that remain fixed
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3. Data Gathering
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Quantitative: numerical
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Qualitative: what our senses detect
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mass, temperature, linear measure, volume
Flavor, color, smell
4. Investigations
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When a controlled experiment is not possible
Involves Observations
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Can’t be completely controlled
Behavior
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Analyze the Data
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Has my hypothesis been _________?
Do I need more data?
Do I need to change my procedure?
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Replicate Experiment to ________ findings.
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Lastly—Report Conclusions
Review Scientific Method
The Scientific Method
Parts of the Scientific
Method
Identify an unknown.
 Make a hypothesis
(a testable prediction).
 Experiment to test
the hypothesis.
 Draw a valid conclusion.

Data
Observations are also called data.
There are two types of data.
qualitative data
quantitative data
descriptions;
no numbers
measurements;
must have numbers
Controlled Experiments
Only one condition is changed at a
time.
The Independent Variable: The condition that
changed or manipulated.
The Dependent Variable: What you are
measuring.
A Controlled Experiment?
Control Experiment Practice
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1.) State Your Problem: Will the salt content of my soil impact the growth of the
corn plants?
2) Hypothesis: Salt in the soil will have an effect on the growth of my corn plants.
3) Design experiment to test your hypothesis (Procedure & Experiment). Collect
data
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Quantitative
qualitative
Analyze data
Does it support your hypothesis?
Theories
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Explanation of a natural phenomenon that is
supported by _____separate observations;
subjected to repeated testing.

Have limited certainties
Scientific Law vs.
Scientific Theory
A law –facts of nature.
Law of Gravity
A theory tries to explain why
or how something happens; supported by many separate
investigations.
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Cell Theory
Atomic Theory
No amount of experimentation can ever prove
me right;
A single experiment can prove me wrong."
- Einstein
Unit 1: ECOLOGY
Chapter 2
.
Chapter 2:
Principles of Ecology
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Ecology: Study…
Organisms and their
environment.
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.
Relationships among living
organisms
Interaction with their
environment
Biosphere

The portion of the Earth that
supports life
From
 High in the atmosphere
 To the bottom of the ocean
Components of the Biosphere

Biotic Factors: Living

Abiotic Factors: Nonliving

Organisms are adapted to surviving in the abiotic
factors in their natural environment.
Abiotic factors: influence what survives.
For Example:Ozone Layer

Region 17 to 27 kilometers above sea level in the
stratosphere

Molecules of ozone absorb most layers of
ultraviolet light

Protects living organisms from excess exposure to
UV light
Levels of Organization-used to
study these interactions.
1. Individual Organism
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An individual organism.
2. Population
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Members of the same
species
may interbreed
living in same place at
same time.
Compete for….
3. Biological Community
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Interacting populations
Occupy same geographic area at same time
Biological Community
Factors Shaping
Community Structure
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Climate and topography
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Available foods and resources
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Adaptations of species in community
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Species interactions
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Arrival and disappearance of species
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Physical disturbances
Ecosystem
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A biological Community AND the abiotic
factors that affect its make-up.
Ecosystem
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Ecosystems can change

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Because the animals, plants and abiotic factors
within may change.
Boundaries somewhat flexible

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Coral reef
A puddle
Biome
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Formed by a group of ecosystems
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That share the same climate & have similar types
of communities
Examples: Marine, Fresh Water, Desert
Biosphere
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Highest level of Biological Organization
Ecosystems- 2major
kinds
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1. Terresterial
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2. Aquatic
 Marine (saltwater)--70 % of
Earth’s
surface
 Freshwater: ponds, lakes, streams
Ecosystems Interactions

Habitat-place where org. lives

Example: for a bird
A single tree
 A grove of trees

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Several species may share a habitat
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Examples: stream, lawn

Niche: An organism’s role in its environment

How it meets its needs for food, shelter and
reproduction.
Community Interactions
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1. Competition
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2. Predation
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Animals
Even some plants-Venus Fly Trap
3. Symbiotic Relationships: close relationship
between 2 + species that live closely together.

3 Kinds
3 types of Symbiosis
COMMENSALISM
PARASITISM
MUTUALISM
One species benefits One species benefits,
Both species benefit.
AND the other is
AND one is harmed—
Some obligatory
Either unharmed
But usually not killed.
nor is benefited.
Example:
Example:
Examples:
Lichen( fungi & algae)
Lichens on a tree
ticks, heartworms
Parasitism
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Natural selection favors parasites
that do not kill
their host too quickly.
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SYMBIOSIS-What
kind is this??

Isn't Symbiosis cool?
That's when two different
species live together and help
each other to survive.
<== In this case the tickbird
is eating the ticks off the
zebra. This partnership feeds
the bird and keeps the zebra
from having ticks sucking on
it.
Mutualism example: Yucca and
Yucca Moth

Moth feeds AND pollinates

Moth larvae can grow only in that
one species of yucca
Commensalism:
Spanish Moss ;Orchids
2.2: Flow of energy in an Ecosystem

2 ways organisms obtain food for energy.

1. Autotrophs
2. Heterotrophs

Tracing the Energy Flow.

Sun—ultimate source of
energy for the planet.
energy
input from
sun
PHOTOAUTOTROPHS
(plants, other producers)
nutrient
cycling
HETEROTROPHS
(consumers, decomposers)
energy output (mainly heat)
1. The Producers: Autotrophs

Able to make their own food.
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Capture sunlight or chemical energy & convert it
into energy-rich compounds (like glucose)
Plants, algae, SOME bacteria
Foundations for all ecosystems!!!
2. Heterotrophs

Gets its energy from consuming other organisms

Also called Consumers
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Herbivores
Carnivores
Omnivores
Detritivores (decomposers): eat fragments of dead matter & return
nutrients to the ecosystem—making it available for the Producers.

Fungus, some bacteria –planet’s biggest decomposers.
Flow of matter and Energy in
Ecosystems

Matter and energy is cycled.
3. Models of Energy Flow through
an Ecosystem
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1. Food Chains
2. Food Webs
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Each step in FC & FW : Tropic Level
3. Ecological Pyramids
Food Chains

Simplified model
Linear
Shows only one possible route of energy
transfer and material in an ecosystem.
Many other routes exist.
Arrows represent one-way energy flow

From Autotroph to heterotroph
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Trophic Levels
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Represent Links in the Chain
All the organisms at a given trophic level are the
same number of steps away from the energy input
into the system
Producers are closest to the energy input and are
the first trophic level.
Trophic Levels-feeding relationships

Primary Producers
Primary Consumers: Herbivores
Secondary Consumers: Carnivores that eat Herbivores
Tertiary Consumers: Carnivores that eat other carnivores

Detritivores– heterotrophs found at varying levels
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Food Web
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
A network of interconnected Food Chains in
an ecosystem.
All the possible feeding relationships between
organisms living within an ecosystem.
Most org. feed on more than one species.
Food Web.
The arrows
indicate the
flow of
materials and
energy being
passed along
Identify the Food Chains
Instructions:
Get out your markers and highlighters!! Step 1: Print this page out.
Step 1: Use the picture above to answer the following question.
1. Identify the organism(s) that are producers?
2. Identify the organism(s) that are consumers?
Identify them as one of the following: Producers; Primary Consumers; Secondary
Consumers; Tertiary Consumers
2. Identify all the food chains food chains 4. How many food chains can you find in the above
food web?
Food Web Assignment: Name: _________________ Due:__________

35 point assignment

You will turn in: Food Web poster with Key and Answers to 3 questions together.
 ( 30 points for both these items) Food web, with key (see below): on a poster board
maximum

( 5 points) Answers to the 3 questions below (typed, complete sentences (or a ven
diagram)—with the questions):
 (attach these to an area of your poster—the front).




1. What is the difference between a Food Web and a Food Chain?
2. What do the arrows indicate?
3. What would be a possible impact on this ecosystem if one of the Primary Consumers was removed
(disease wiped them out), and explanation?
Your full name and class section are to be on the poster.

The Food Web Details:

A). ( 20 points) Make a food web for an ecosystem. ( you can even make one up!)
B). This food web should include a minimum of 10 food chains.
C) ( 10 points) Make a key for the following:





producers, primary consumers, secondary consumers, tertiary consumers,
detritivore.
Paste/tape ( or draw) the pictures to/onto posterboard
.
Draw arrows connecting the organisms to show feeding relationships.

Be sure your arrows are pointing in the direction that the energy flows.
Use magazines or other picture source ( hand drawing would be great) Possible magazines to search: Dog Fancy,
National Geographic, Field and Stream, Outdoor Life.
Food Web Assignment: Name: _________________ Due:__________

35 point assignment

You will turn in: Food Web poster with Key and Answers to 3 questions together.
 ( 30 points for both these items) Food web, with key (see below): on a poster board
maximum

( 5 points) Answers to the 3 questions below (typed, complete sentences (or a ven
diagram)—with the questions):
 (attach these to an area of your poster—the front).




1. What is the difference between a Food Web and a Food Chain?
2. What do the arrows indicate?
3. What would be a possible impact on this ecosystem if one of the Primary Consumers was removed
(disease wiped them out), and explanation?
Your full name and class section are to be on the poster.

The Food Web Details:

A). ( 20 points) Make a food web for an ecosystem. ( you can even make one up!)
B). This food web should include a minimum of 10 food chains.
C) ( 10 points) Make a key for the following:





producers, primary consumers, secondary consumers, tertiary consumers,
detritivore.
Paste/tape ( or draw) the pictures to/onto posterboard
.
Draw arrows connecting the organisms to show feeding relationships.

Be sure your arrows are pointing in the direction that the energy flows.
Use magazines or other picture source ( hand drawing would be great) Possible magazines to search: Dog Fancy,
National Geographic, Field and Stream, Outdoor Life.
Energy and Trophic Levels
Ecological Pyramids(see p. 52)


Model energy flow through ecosystem.
3 Types

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
1. Pyramid of Energy
2. Pyramid of Numbers
3. Pyramid of Biomass
Show the relative amounts of energy, biomass or
numbers of organisms at each tropic level in an
ecosystem.
1.Pyramid of Energy (flow)

Each level represents the energy available within
that trophic level.
top carnivores
21
carnivores
herbivores
383
decomposers
3,368
producers
20,810 kilocalories/square meter/year
detritivores
Energy Losses

Energy transfers are never 100 % efficient.

Some energy is lost at each step.
Pyramid of Energy


The amount of energy available decreases with
each succeeding trophic level.
Total energy transfer to next level is 10%

90% is transformed

Energy for organism or as heat
Least Energy Available
Most Energy Available
2. Pyramid of Biomass

The total mass of living
matter at each tropic
level.

Decreases
3. Pyramid of Numbers

Relative number of organisms
also decreases at each
successive tropic level.—

there is less energy available
to support organisms.

.
Biological Magnification
A nondegradable or slowly degradable
substance becomes more and more
concentrated in the tissues of organisms at
higher trophic levels of a food web
How biomagnification works:
Injested chemical becomes
increasingly concentrated .
DDT in Food Webs

Synthetic pesticide banned in
the United States since
1970s.

Top carnivore birds
accumulated DDT in their
tissues.
Shells are soft, crack, babies die.
DDT banned in US in 1972!
Biome Project
Choose a group of 3 students
 Select a specific biome
 Get approval
 Each person will have a role in the presentation
Each will turn in a summary for their job.


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Botanist
Zoologist
Meteorologist
Cycling of Matter

Law of conservation of mass.


Natural processes cycle matter through the
biosphere.
Matter:

Nutrient:

Nutrient cycling: organism and physical forces
involvement.
Cycles in the Biosphere

Biogeochemical Cycle: The exchange of
matter through the _____________.

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
Living organisms
Geological processes
Chemical processes
4 Major Cycles biologygmh.com

1. Water –or Hydrologic cycle

2. Carbon Cycle

3. Nitrogen cycle

4. Phosphorous Cycle
Water Cycle Constantly moving from
Earth to atmosphere.
Atmosphere
Precipitation
evaporation from
ocean
4
Transpiration
precipitation into ocean
surface and groundwater f
Land
Oceans
The Water Cycle

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
Evaporation and Transpiration, respiration
release water into the atmosphere;
forms rain, snow or ice;
falls back to earth, bodies of water;
Percolation
Evaporation; absorption by autotrophs
2. The Carbon Cycle

Life based upon carbon molecules.
Such as …
DNA, Proteins, Carbohydrates, Fats
Carbon in Atmosphere

Atmospheric carbon is mainly carbon dioxide

Carbon dioxide is added to atmosphere…..


Aerobic respiration, volcanic action, burning fossil fuels
Removed by plants (photosynthesis)
Carbon Cycle
diffusion
Atmosphere
volcanic action
Bicarbonate,
carbonate
TERRESTRIAL
ROCKS
photosynthesis
Terrestrial
Rocks
Land Food
Webs
Marine food
webs
Soil Water
weathering
Marine Sediments
Peat, Fossil
Fuels
3. The Nitrogen Cycle

Critical for living organisms


Protein & DNA
78% of atmosphere is Nitrogen


Not usable by plants in this form
Converted by bacteria in soil.
CLASS ACTIVITY

Using your textbook, in trios, IDENIFY THE
ROLES OF THE PRODUCERS,
CONSUMERS, AND DECOMPOSERS IN
THE CYCLING OF NITROGEN.
Nitrogen Cycle
GASEOUS N ITROGEN
(N2) IN ATMOSPHERE
NITROGEN
FIXATION
by industry for
agriculture
FOOD WEBS
ON LAND
FERTILIZERS
NITROGEN FIXATION
NH3-, NH4+
IN SOIL
loss by
leaching
uptake by
autotrophs
excretion,
death,
decomposition
NITRO GENOUS WASTES,
REMAINS IN SOIL
AMMONIFICATION
1. NITRIFICATION
uptake by
autotrophs
NO3IN SOIL
2. NITRIFICATION
NO2IN SOIL
loss by
leaching
The 2 ways P cycles
1.Plants get phosphorous from soil.
Animals eat plants.
Organisms die, decomposers return it to the soil.
2. Also incorporated into rocks; upon weathering; it is
returned as runoff!
Phosphorus Cycle
mining
excretion
FERTILIZER
GUANO
agriculture
uptake by
autotrophs
MARINE
FOOD
WEBS
weathering
DISSOLVED
IN OCEAN
WATER
uptake by
autotrophs
weathering
DISSOLVED IN
SOILWATER,
LAKES, RIVERS
death,
decomposition
sedimentation
death,
decomposition
leaching, runoff
setting out
uplifting over
geolgic time
MARINE SEDIMENTS
ROCKS
LAND
FOOD
WEBS
Greenhouse Effect

Greenhouse gases impede the
escape of heat from Earth’s surface
Global Warming

Long-term increase in the temperature of
Earth’s lower atmosphere
Carbon Dioxide Increase

Carbon dioxide levels fluctuate seasonally

The average level is steadily increasing

Burning of fossil fuels and deforestation are
contributing to the increase
Other Greenhouse Gases

CFCs - synthetic gases used in plastics and in
refrigeration

Methane - produced by termites and bacteria

Nitrous oxide - released by bacteria, fertilizers, and
animal wastes
Nitrogen Fixation

Plants cannot use nitrogen gas

Nitrogen-fixing bacteria convert nitrogen gas
into ammonia (NH3)

Ammonia and ammonium can be taken up by
plants
Ammonification & Nitrification

Bacteria and fungi carry out ammonification,
conversion of nitrogenous wastes to ammonia

Nitrifying bacteria convert ammonium to nitrites and
nitrates
Nitrogen Loss

Nitrogen is often a limiting factor in ecosystems

Nitrogen is lost from soils via leaching and runoff

Denitrifying bacteria convert nitrates and nitrites to
nitrogen gas
Human Effects

Humans increase rate of nitrogen loss by clearing
forests and grasslands

Humans increase nitrogen in water and air by using
fertilizers and by burning fossil fuels

Too much or too little nitrogen can compromise plant
health