Evolution and the Classification of Life

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Unit 3

• Evolution and the Classification of Life

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Inquiry Assignment

• The question is often asked Why are we learning
  this? How is it relevant to my life?
• You have received a handout titled Relevance of
  Evolution this assignment has been divided into
  four main areas, you will be responsible for only
  the on specified on your assignment hand-out
• Agriculture
• Medicine
• Conservation
• Co-evolution of Species

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• Due Date Friday, May 8th
• Ideas for an open Media Rubric
• Essay
• Poster
• Pamphlet
• Video
• Webpage
• Use the class-time provided (Monday-Wednesday) to
  navigate the website, record key questions and
  record some notes that will help answer each key
  question
• Before beginning your project, carefully read
  through the evaluation rubric and ask any
  questions before you begin

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Unit Notes

• This unit will correspond to Unit 5 in your
  Textbook (pp. 366-467)
• Chapter 15 Darwin's Theory of Evolution
• Chapter 17 The History of Life
• Chapter 18 - Classification

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Darwins Theory of Evolution

• Evolution means simply change over time
• Observed evidence confirms that modern day
  organisms have descended from more ancient
  ancestors
• The scientific theory of evolution is an
  explanation for why things change over time
• This theory has greater support due to intense
  investigation than either atomic or gravity
  theories.

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The Travels of Charles Darwin

• During his travels along the H.M.S. Beagle,
  Darwin made many observations and collected
  evidence from both living species and fossils.
• This led him to propose a hypothesis about the
  mechanism behind how life changes over time
• Darwin observed that the characteristics of many
  animals and plants varied noticeably as he went
  from island to island in the Galapagos

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• Q Describe Darwin's Journey on the Beagle
• Figure 15-1 (p.369)

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Darwins ObservationsPatterns of Diversity

• During 1 day in the Brazilian rainforest, Darwin
  identified 68 different beetle species despite
  the fact he wasnt even looking for beetles
• Darwin began to realize the magnitude of
  biodiversity on earth
• Darwin found that animals are remarkably well
  suited to their environment, sharing advantageous
  characteristics
• Europe held surprisingly similar grassland
  ecosystems of Argentina or Australia, however the
  organisms found in the grasslands differed
  greatly, why no rabbits in Australia? Why no
  Kangaroos in England?

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Darwins ObservationsLiving Organisms and
Fossils

• Living organisms are only a piece of the puzzle
  Darwin also collected the ancient remains of long
  dead organisms, called fossils
• Some fossils resembled those of living species,
  others looked like no other species ever observed
• Questions that arose included
• Why do species disappear?
• How are they related to living species?

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Darwins ObservationsThe Galapagos Islands

• The most influential of all Darwins travels were
  the Galapagos Islands
• Although close together, each island had a unique
  climate
• Hood (smallest and lowest) was hot, dry and
  barren
• Very sparse vegetation
• The Higher the altitude of the island, the
  greater the rainfall and as a result, the greater
  the amount of vegetation and animal-life
• Certain animals, such as the Giant Tortoise,
  varied predictably from island-to-island

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Pinta
Tower
Marchena
Pinta IslandIntermediate shell
James
Fernandina
Santa Cruz
Isabela
Santa Fe
Hood Island Saddle-backed shell
Hood
Floreana
Isabela Island Dome-shaped shell
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Darwins Theory - Summarized

• Individual organisms differ some of this
  variation is heritable (can be passed on to
  offspring)
• Look around the classroom, what traits vary from
  person to person?
• Organisms produce more offspring than can
  survive, and many that do survive do not
  reproduce
• Some organisms never reach maturity due to
  starvation or predation for example many of
  those that do survive are often sickly or not
  healthy enough to reproduce
• Because more organisms are produced than can
  survive, they compete for limited resources
• The organisms best able to find and use resources
  are more likely to survive and reproduce.

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• Each organisms has different advantages and
  disadvantages in the struggle for existence.
  Individuals best suited to their environment
  survive and reproduce most successfully. These
  organisms pass on their heritable traits to their
  offspring. This process of natural selection
  causes species to change over time.
• The environment dictates who survives, and does
  not always correspond to the fastest or
  strongest.
• Species alive today are descended with
  modification from ancestral species that lived in
  the distant past. This process by which diverse
  species evolved from common ancestors, unites all
  organisms on earth into a single tree of life
• All organisms share certain characteristics in
  common

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Assignment

• Survival of the Sneakiest
• Read the hand-out and complete the questions at
  its conclusion in your notebook on a new piece of
  loose leaf. Hand in by the end of class.

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• Like any theory, evolutionary theory continues to
  change as new data comes to light
• Evolutionary theory provides vital insights to
  ecological and medical problems, giving us the
  expertise to understand and prevent harmful
  changes in our environment
• Questions still remain
• How do new species arise?
• Why do species go extinct?
• How did life begin?

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Ideas that Shaped Darwin's Thinking

• During Darwins era, the scientific world was
  coming to terms with both
• Geologist James Huttons 1795 assertion that the
  world was more than thousands of years old, but
  rather millions was critical to Darwins theory
  (small changes accumulating over vast periods of
  time)
• Charles Lyells assertion that scientists can
  only explain past events in terms of processes
  that they can observe currently, as the processes
  that shape our world today indeed shaped the
  ancient world as well supported Darwins theory
  (mechanism for change is the same now as in the
  past)

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• Jean-Babtiste Lamarck was the first scientist to
  put forward the idea that living things change
  over time his explanation stated
• By selective use and disuse of organs, organisms
  acquired or lost certain characteristics in their
  lifetime
• These traits were passed on to offspring and over
  time this process led to considerable change in
  the overall species

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• Lamarckian evolution includes
• Tendency towards perfection
• An innate (built-in) tendency exists within
  organisms toward complexity and perfection
• Use and Disuse
• Can alter the size or shape of their body in new
  ways (i.e. work out and become stronger a bird
  that refuses to fly would lose its wings over
  time)
• Inheritance of Acquired Traits
• If during its lifetime, an organisms grew longer
  legs or fluffier feathers, it would pass that
  trait on to its offspring

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Lamarckian Evolutionary Theory
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• Lamarck was incorrect in several ways, namely
  that an organisms behavior has no impact on its
  heritable characteristics
• Ex. if you lose your hands in an accident, your
  child will be born with both hands
• Lamarck was revolutionary for his time however,
  as he put forward the idea that organisms adapt
  to their environment, paving the way for Darwin
  and other scientists

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How are Lamarck and Darwin Different?

• Lamarck suggested that organisms choose their
  characteristics
• Darwin suggested that natural variation exists
• Lamarck suggested that organisms evolve to become
  perfect
• Darwin put forward that evolution occurs only in
  response to a change in the environment i.e.
  nature selects which organisms are best suited to
  survive.

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• Thomas Malthus is often associated with
  doomsday whereby the human species would
  collapse people that believe mankind is due for
  a collapse are often called Malthusian
• Malthus believed that if the human population
  continued to grow unchecked, sooner or later
  there would be insufficient space and food for
  everyone
• Darwin supposed that this tendency was more
  applicable to plants and animals, as they produce
  more offspring than are capable of survival (i.e.
  1 oyster can produce 1 million eggs per year
  only a small fraction will survive)
• Q What factors determine which offspring are
  capable of survival and reproduction?

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Video Assignment

• Watch each video segment, following a quick class
  discussion, answer each question with as much
  detail as possible.
• Q What is wrong with the statement Evolution
  is just a theory?
• Q Who Was Charles Darwin?
• Q How do we know evolution happens?
• Q How does evolution really work?
• Q How did humans evolve?
• Q Why does evolution matter now?
• Optional Question
• Q Why is evolution controversial anyway?

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Quick AssignmentEvolutionary Classification

• Construct a table that has five columns and six
  rows.
• In the columns, write the following heads Animal
  Group, Example, Legs, Fins, and Tail.
• Place the following animal groups in their own
  row Mammal, Bird, Fish, Amphibian, Reptile, and
  Insect.
• Give one example for each group, and then fill in
  the information for that example. For Legs, write
  in the number of legs that each animal has. Do
  animals with fins have legs? Do animals with
  wings have legs? If so, how many?
• Can you tell from your table if a fish is more
  closely related to a bird or to an amphibian?
  Explain your answer.
• Cosmos with Carl Sagan - Evolution

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1. What does the following picture illustrate about
   the distribution of similar species?
2. Do you believe these organisms are closely
   related? Why?
3. Which animal has a larger geographical range, the
   coypu or the muskrat?

Figure 15-14 (p.383)
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Homologous structures (fig. 15-15, p.384)
Homologous structures are one type of evidence
for the evolution of living things.
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Practical Applications of Darwins Theory

• Prior to Darwin, variation among species was seen
  as an unimportant, minor defect
• In artificial selection, nature provides the
  variation in a species, and humans select those
  variations found useful
• Artificial selection has given rise many domestic
  plants and animals by selectively breeding for
  different traits.
• Meet the Super-cow
• Warning some images of artificial insemination
  may be too graphic for some students please put
  your head down if you do not wish to watch
• Optional Video Samurai Faced Crab

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Chapter 15 - Assignment

• 15-1 (p.372)
• Focus on the Big Idea
• 15-2 (p.377)
• 5
• 15-3 (p.386)
• 2, 3

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Notebook Check 3

• Chapter 5 Review
• 5-1 3-5, 5-2 1-5, 5-3 1,2,4,5
• Justicia Now
• Humans in the Biosphere
• 2column chart
• Types of human activities
• Impact
• 6-2 Assignment
• 1, 2, 3, 5
• How Much Should it Cost?

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The History of Life

• The fossil record provides evidence about the
  history of life on earth, it reveals how
  different groups of organisms have changed over
  time
• There are two ways to date fossil evidence
• Relative Dating Dating a fossil relative to the
  proximity to different types of sedimentary rock
  and other fossils
• Radioactive Dating Calculate the absolute age
  (in years) of a fossil based on the remaining
  isotopes contained within
• Video

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Comparing Relative and Absolute Dating of Fossils
Relative Dating
Absolute Dating
Can determine Is performed by Drawbacks
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How Do Fossils Form?
The preserved remains may later be discovered and
studied.
Water carries small rock particles to lakes and
seas.
Dead organisms are buried by layers of sediment,
which forms new rock.
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Fossil Formation Activity

• Receive Answer Sheet complete while we navigate
  online
• Web-link

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Mystery Detective

• Earth is billions of years old. There were not
  any witnesses to those early years. How, then,
  can scientists determine the conditions on Earth
  long before there were any scientists?
• Think about how you draw conclusions about
  occurrences that you did not witness. If you saw
  the charred remains of a house, for example, you
  could infer that it burned down.
• List things that you can observe around you that
  lead you to infer about events you did not see.
  (For example, what do skid marks in the roadway
  tell you?)
• Now, think about and list the evidence all around
  you that scientists might analyze when trying to
  piece together a history of Earth. How would
  finding the fossil of a sea animal in the middle
  of a desert tell a scientist something about the
  past?

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Evolution of Life A Concept Map
Early Earth was hot atmosphere contained
poisonous gases.
Earth cooled and oceans condensed.
Simple organic molecules may have formed in the
oceans..
Small sequences of RNA may have formed and
replicated.
First prokaryotes may have formed when RNA or DNA
was enclosed in microspheres.
Later prokaryotes were photosynthetic and
produced oxygen.
An oxygenated atmosphere capped by the ozone
layer protected Earth.
First eukaryotes may have been communities of
prokaryotes.
Multicellular eukaryotes evolved.
Sexual reproduction increased genetic
variability, hastening evolution.
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The Miller- Urey Experiment
Mixture of gases simulating atmospheres of early
Earth
Spark simulating lightning storms
Cold water cools chamber, causing droplets to form
Condensation chamber
Q Describe the Miller-Urey Experiment in your
own words.
Water vapor
Liquid containing amino acids and other organic
compounds
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Origin of Complex Life Endosymbiotic Theory
Video
Chloroplast
Plants and plantlike protists
Aerobic bacteria
Ancient Prokaryotes
Photosynthetic bacteria
Nuclear envelope evolving
Mitochondrion
Primitive Photosynthetic Eukaryote
Animals, fungi, and non-plantlike protists
Primitive Aerobic Eukaryote
Ancient Anaerobic Prokaryote
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Patterns of Evolution

• Macroevolution are the large scale patterns and
  processes that occur over long periods of time.
  The 6 major topics are
• Extinction
• Adaptive Radiation
• Convergent Evolution
• Co-evolution
• Punctuated Equilibrium
• Changes in developmental Genes

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Chapter 17 - Assignment

• 17-1 (p.422)
• 3, 5
• 17-2 (p.428)
• 1-4
• 17-4 (p.440)
• 1-3, Thinking Visually

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Analyzing DataChanging Number of Marine Families

• Complete Activity on p.438 on separate piece of
  paper
• Due Date Today, end of class

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ExplorationModeling Adaptation (20 Marks)

• Complete the activity as described on p.387
• Complete 3 Rounds of this activity with your
  partner, recording your data each time (what was
  role, your habitat, your score, the result)
• Your write-up must include
• Name, Date, Title, Partners
• Sections Problem, Materials, Procedure, Data,
  Analysis/Conclusion (questions)
• Complete the Go Further activity for 5 bonus
  marks, capped at 100

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Evolution Unit Review

• Ch. 15 Assessment (p. 389)
• Complete 1-10, 27-30, 32, 34
• Ch. 17 Assessment (p.443)
• Complete 1-7, 9-10, 27-31

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Icons of Science - Evolution

• During the course of this video, record some
  brief notes from each section that seem
  significant or are of interest
• These notes will be part of a notebook check at a
  later date.

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Taxonomy

• Evolution is the process by which new organisms
  come to be natural selection is the mechanism
  behind it.
• To study the diversity of life, we must develop a
  classification system to name organisms and group
  them appropriately
• This discipline is called taxonomy
• Web-activity Sample

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• To avoid confusion caused by regional names, the
  taxonomic system must be universal across borders
  and languages.
• i.e. a Cow, Vache, Krava, Waka, Ushi are all
  names for the same organism the taxonomic name
  bos primegenius is universal in all languages and
  countries
• Q What Canadian animal has more than one common
  name?
• A Mountain Lion, Puma, Cougar, Panther all
  represent the same animal, Felis concolor

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Binomial Nomenclature

• Each species is assigned a two part name the
  name is written in italics, the first word is
  capitalized, the second word is not.
• The first name corresponds to the genus, which
  represents a group of closely related organisms
• The second name corresponds to the species

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• Carolus Linnaeus was a swedish botanist, who
  developed a system that became the forerunner to
  the modern taxonomic system
• Each level of this system is called a taxon

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Linnaeuss System of Classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
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Sea star
Grizzly bear
Coral snake
Abert squirrel
Black bear
Giant panda
Red fox
KINGDOM Animalia

• The system is organized from the general to the
  specific

PHYLUM Chordata
CLASS Mammalia
ORDER Carnivora
FAMILY Ursidae
GENUS Ursus
SPECIES Ursus arctos
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Kingdom

• The Largest and most inclusive taxon separates
  organisms on a very basic and elementary level
• Linnaeus originally recognized only two kingdoms
• Plantae
• Animalia
• In years to come, new kingdoms would be created
  to classify microorganisms like Bacteria and
  Protists

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Phylum

• The 2nd largest group, separates organisms by a
  more specific characteristic
• Consists of a group of similar classes of
  organisms
• i.e. Phylum Chordata consists of all organisms
  with a spinal chord
• These organisms share many aspects of their body
  plan and internal functions in common

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Class

• The 3rd largest group, even more specific
  characteristics are used to differentiate these
  organisms
• Made up of similar orders of organisms
• i.e. Class Mammalia contains all organisms that
  are warm blooded, have body hair and produce milk
  for their offspring

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Order

• Broad category composed of similar families
• i.e. the Order Carnivora contains many organisms
  with similar characteristics
• Q What characteristics might they share?

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Family

• A specific group of organisms that share a great
  deal of characteristics with one another
• Composed of similar Genuss
• i.e. The Family Ursidae is composed of all
  existing bear species

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Genus

• Small Group of very similar organisms
• Composed of similar species
• The Genus Ursus includes the grizzly and polar
  bear the panda is in a separate genus called
  Ailuropoda

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Species

• Often a Latinized description of a unique
  characteristic or native location of the organism
• i.e. Ursus Maritimus would refer to a bear that
  lives near the sea or on floating ice pack, in
  this case a polar bear.
• Q What type of organism is Panthera leo?
• A Lion

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One Big Family

• How can you determine if one organism is closely
  related to another? It may seem easy, but it
  isnt, and looks are often deceiving. For
  example, roses and orchids are both flowering
  plants, but roses grow on bushes or vines and
  have thorns. Many orchids dont even grow in
  soilthey can grow in trees! Rose and orchid
  blossoms look very different, and roses and
  orchids cannot produce hybrids, or offspring of
  crosses between parents with different traits.

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• Do you think roses and orchids are closely
  related? Explain your answer.
• Now, apply the same logic to dogs. Different
  breeds of dogssuch as a Labrador retriever and a
  colliecan breed and produce offspring. So what
  is the difference between the rose-orchid
  combination and the Lab-collie combination?
• What defines a species? Is appearance important?
  What other factors might be considered?

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Assignment

• Read Ch. 18-1
• Complete questions
• 4-6
• Video

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Modern Evolutionary Classification

• Physical similarities are only a piece of the
  whole classification puzzle
• How closely related are bats, bees and birds?
• With the advent of Darwinian Evolution,
  biologists now group organisms into categories
  that represent lines of evolutionary descent
  (phylogeny)
• Species within a genus share a recent common
  ancestor, whereas species of different genus but
  still in the same family share a more distant
  ancestor
• Organisms that superficially appear similar may
  not share a recent ancestor (i.e. convergent
  evolution)

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Classifications using Cladograms

• As unique characteristics evolve, new species are
  formed we call these characteristics derived
  characters
• Derived characters are used to construct a
  cladogram, a diagram which illustrates the
  relationships between organisms as it relates to
  recently derived characters and more ancient ones.

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Crab
Crab
Limpet
Limpet
Barnacle
Barnacle
Molted exoskeleton
Segmentation
Tiny free-swimming larva
CLASSIFICATION BASED ON VISIBLE SIMILARITIES
CLADOGRAM
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Quick Lab How is a Cladogram Constructed?
(p.453)

• On a separate piece of paper, please complete
  this activity and turn it in next day.
• Cladogram (3 marks)
• Questions (6 marks)

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Six Kingdom Classification System

1. Eubacteria single celled prokaryotic organisms
   with a cell wall composed of peptidoglycan
2. Archaebacteria single celled prokaryotic
   organisms with a unique cell wall extremophiles
   (love extreme environments)
3. Protista single celled organisms with varied
   characteristics (if it doesnt fit anywhere
   else)
4. Fungi heterotrophic organisms with cell walls
   made of chitin generally decomposers
5. Plantae Photosynthetic multi-cellular organisms
   with cell walls made of cellulose
6. Animalia Heterotrophic organisms without a cell
   wall, capable of locomotion

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3 Domain System

• Scientists have recently proposed a more general
  taxon than Kingdom called a Domain
• The 3 Domain System consist of
• Bacteria corresponds to kingdom Eubacteria
• Archaea corresponds to kingdom Archaebacteria
• Eukarya Correpsonds to kingdoms protista,
  fungi, animalia and plantae

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The Tree of Life (aka a cladogram)
Kingdoms
Eubacteria Archaebacteria Protista Plantae Fungi A
nimalia
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Living Things
are characterized by
Important characteristics
which place them in
and differing
Domain Eukarya
Cell wall structures
such as
which is subdivided into
which place them in
which coincides with
which coincides with
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Real World LabClassifying Organisms Using a
Dichotomous Key (p.462)

• Complete the Lab as described on p.462.
• Must include Title, Name, Partners Name (if
  necessary), Date, Problem, Materials, Data,
  Analysis (questions), and Conclusion
• Part A must be completed independently
• Part B may be completed independently or with a
  single partner you must include their name at
  the beginning of you lab report
• 4 questions a conclusion are necessary in the
  writeup
• Completing the Go Further portion of the
  activity is worth 5 bonus marks, capped at 100
  (if you have

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Closed-book midterm 2

• Closed book
• Covers all notes and activities from last midterm
  to this point
• Corresponds to Chapters 15, 17 and 18 in our text
• Based on previous open-book Unit Exams same
  format
• Date Tuesday, June 2nd

70
Exam Review

• Ch. 18 Assessment (p.465)
• Complete 1-10, 26-30

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