Download Chapter 11 Section 1: Sorting It All Out

Chapter 7: Classification of Living Things
Sorting It all Out
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Prior to the 1700’s scientists had no rules for naming
and grouping of organisms
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Multiple names were used for the same organism and
caused confusion
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Scientist needed a universal means of organizing and
naming organisms.
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Classification and Taxonomy were developed in 1700’s
by Carolus Linnaeus who classified more than 11,000
species based on their structure.
Why Classify?
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To make sense and order of the organisms in the world
based on shared characteristics.
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Classification – the division of organisms into groups or
classes, based upon specific characteristics
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Scientists classify organisms using Taxonomy
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Taxonomy is the science of describing, classifying and
naming organisms. Taxonomists use biological, physical
and genetic evidence for classification
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Systematics is the classification of organisms by their
characteristics
How do Scientist Classify Organisms?
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Scientists use dichotomous keys for identifying species
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A dichotomous key is an identification tool that gives a
series of choices that gradually narrows down the list of
possible species (see pg. 230)
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A dichotomous key is useful only when you know what
type of organism you are observing and therefore based
on observable traits.
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Complete Classzone Simulations – Dichotomous Key
Branch diagrams shows how organisms
evolved
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A shared derived characteristic is a characteristic that
two or more kinds if organisms share with their more
recent common ancestors.(see pg. 244)
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Branching diagrams show which characteristics
organisms share and when these organisms evolved.
Branching diagrams can be used to understand
evolutionary relationships between extinct and living
organisms by comparing the fossil records and
characteristics of the living organisms. (see pg. 242)
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A cladogram is a branching diagram based upon traits
passed down from common ancestors (see pg. 244)
Levels of Classification:
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All living things are classified into 1 of 3 Domains.
Domains are the largest group. (see pg. 235)
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Each Domain is broken into Kingdoms
Each Kingdom broken into Phyla (singular –Phylum)
Each Phyla is broken into Classes
Each Class is broken into Orders
Each Order is broken into Families
Each Family is broken into Genus
Each Genus is broken in Species
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Remember: Species is a group of organisms able to mate with one another
and produce fertile offspring.
Scientific Names
• Linnaeus simplified naming living things by
giving each species a two-part scientific name
called binomial nomenclature.
• Binomial= two names and nomenclature=a
system of names
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Ex. the house cat is called Felis catus
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Felis is the genera and catus is the species
What is Genus?
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Genus is a group of species that have similar
characteristics
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Ex. Ursus is the genus for bears the second name is the species
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Ursus arctos = grizzly bears Ursus maritimus = polar bears
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Genus names begin with an upper case letter and species
begins with a lower case letter and is italicized. The genus
name is first followed by the species name. The scientific
name is derived from Latin or Greek that contains
information regarding the organism such as
Tyrannosaurus rex. Tyrannosaurus means ‘tyrant lizard’
and rex means ‘king’.
Levels of Classification:
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All living things are classified into 1 of 3 Domains.
Domains are the largest group. (see pg. 235)
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The 3 Domains are the highest level of classification
The 3 domains are: Archaea, Bacteria and Eukarya (pg.
249)
Archaea includes archaea (thermophiles)
Bacteria consists of bacteria (no nuclei)
Eukarya consists of protists, fungi, plants and animals
(larger with more complex structures)
Levels of Classification:
• All living things are classified into 6 kingdoms
(pg. 250):
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Plantae
Animalia
Protista
Fungi
Archaea
Bacteria
Plants and Animals are the two most familiar kingdoms
Plantae
Plants are grouped into 3 main types:
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Bryophytes are nonvascular; they were the first
plants to live on land. Bryophytes include
mosses,hornworts, and liverworts
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Vascular seedless plants have a vascular system but
no seeds. Vascular seedless plants include horsetails
and ferns.
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Vascular seed plants have vascular systems. They
also have seeds for protecting and dispersing embryos.
Vascular seed plants include conifers, or evergreen
trees, ginkgo trees, and flowering plants.Most of the
plants you can think of, such as grass or apple trees, are
flowering plants.Most familiar plants are vascular seed
plants
Animalia
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Scientists have already named a million species in the
kingdom Animalia. Many different types of animals live on
Earth, but more than 90 percent of the named species are
insects.
The animal kingdom also has familiar animals such as
whales, sharks, humans, bears, dogs, and fish.
Animals are classified by their body types, which vary
widely.
Vertebrates are animals with backbones.
Invertebrates, the group that contains the most
individuals, have no backbone. About One million
invertebrate species live on Earth
Protista
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The kingdom Protista includes a wide variety of
organisms.
Most protists are unicellular. The multicellular protists are
too simple to be classified as animals, plants, or fungi.
All protists have large, complex cells with true nuclei.
Some eat other organisms as animals do, some get
energy from sunlight as plants do and some protist
resemble fungi.
Multicellular protists are still much simpler than plants,
animals, and fungi.
Many live in ponds or oceans
Ex. Giant Kelp
Fungi
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Some well-known fungi include mushrooms, molds, and
yeasts.
Both plants and fungi remain rooted in one place.
Most fungi have cell walls like the cells walls of plants.
Unlike plants,fungi do not use sunlight to make food.
Fungi do not “eat” in the same way that animals do.
Instead they use chemicals to break down food outside
of their bodies. Then they absorb, or take in, that food.
Many fungi act as decomposers. They break dead or
decaying matter into simpler parts.
Bacteria
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All are unicellular, small, simple with no nucleus. Most
have a cell wall outside of the cell membrane. This cell
wall is not similar to the cell wall in plants.
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They live everywhere on Earth and can be either
harmful, helpful or have no effect.
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Some conduct photosynthesis, others are decomposers
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Ex. E.coli
Archaea
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Single celled and have no nucleus but have a different
cell structure than bacteria
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Ancient organisms
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Live in extreme environments such as sulfur pits, or
boiling mud geysers.
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Some live in the guts of termites and cows to help break
down cellulose (plant material)
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Ex. Methanococcoides burtonii