IB BIO II
Van Roekel
4/17/14
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Use binomial nomenclature to name and classify
organisms
1st word refers to the genus, 2nd word to the
species, i.e. Homo Sapiens.
Carolus (Carl) Linnaeus consolidated and
popularized binomial nomenclature
Reasons:
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Make sense of biosphere
Identify unknown organisms
Show evolutionary links
Predict characteristics shared by members of a group
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DNA is universal source of genetic
information in all living organisms
◦ Any gene can be mixed and match with DNA from
other organisms and generate a certain protein
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All proteins use same 20 amino acids to form
polypeptide chains
◦ Can have 2 possible orientations, left-handed &
right-handed, all proteins are based on lefthanded orientation
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Chemical similarities suggest common
ancestry for all life
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Study of the evolutionary past of a species
◦ Species that are most similar are closely related
◦ Species with more differences are less likely to be
closely related
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Traditionally done with morphological
characteristics
More recently done by comparing similarities
in polypeptide sequences in proteins such as
hemoglobin, cytochrome C, and cholrophyll
Also done by examining DNA base sequences
1.
2.
3.
4.
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AAAATTTTCCCCGGGG
AAAATTTACCCCGGGG
AAAATTTACCCGCGGG
AACATCTTCCACGCTG
1 & 2 most similar/closely related
1 & 4 most differences/less related
Use biochemical phylogenies to
confirm/contradict work done by paleontologists
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Differences in DNA & polypeptide sequences
occur over time through mutations and sexual
reproduction
Changes can be used as a “clock” to estimate
how far back the species split
Compare homologous molecules and count the
number of base pairs that don’t match
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3 organisms: A,B,C
A&B 23 differences, A&C 83 differences
A&B more closely related than A&C
Split between A&C occurred roughly three times further
in the past than A&B
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Technique that measures differences in DNA
sequences
Take sample of DNA from one species (A) and fuse
it with sample from another species (B)
Where connections occur, base pairs match
Where no connections, base pairs repel and there is
a difference
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Cladistics is a system of classification which
groups taxa together according to characteristics
which have most recently evolved
Examine primitive (plesiomorphic) traits and
derived (apomorphic) traits
◦ Primitive traits have same structure and function, and
evolved early on in organisms being studied (leaves with
vascular tissue in plants)
◦ Derived traits also have same structure and function but
evolved more recently as modifications of previous traits
occurred (flowers with vascular tissue which evolved
more recently than leaves)
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When groups are split
into two parts, one
having derived
characteristics and the
other does not, the
groups form two
separate clades
Monophyletic groups,
composed of the most
recent common
ancestor and all its
descendants
Usually made up of
several species
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Used to help separate individuals in to
different clades
Homologous Structures are derived from the
same part of a common ancestor
◦ Pentadactyl limb in animals such as humans,
whales, and bats
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Analogous Structures have same function but
do not necessarily have same structure and
are not derived from a common ancestor
◦ Wings in birds, bats, and insects
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Cladograms are diagrams that visually represent
the findings of cladistics
Shows evolutionary relationships with bottom
branches showing earliest evolved organisms and
top branches most recently evolved
Basic idea is parsimony, meaning the least
complicated explanation is preferred
Each time a branch forks into two, a split
between species occurred creating two lineages,
each split is called a node
Each node shows speciation
Can be made using biochemical and
morphological examples
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The simplified cladogram of vertebrata is shown with synapomorphies
indicated.
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What organisms have bony ribs and shoulder girdles?
◦ Ray-finned fish, lungfish, amphibians, and land vertebrates
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What is the oldest creature in this cladogram? They youngest?
◦ Lampreys, landvertebrates
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What feature is shared by amphibians and land vertebrates?
◦ Have fingers and toes
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What feature did the common ancestor of lungfish and lampreys
have?
◦ Vertebrae
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What creature is most closely related to land vertebrates? Lampreys?
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Amphibians, Sharks
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Construction of Cladograms
◦ Make a list of included organisms
◦ List as many characteristic each organisms posses
◦ From established list, find a characteristic common
to all organisms (primitive characteristic)
◦ Make a table with derived characteristics on top row
and organisms in first column. (shows derived
characteristics in each organism
◦ Construct cladogram from table, organism with
least derived traits is on first branch, organism with
most derived characteristics is on top branch
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Use the following information to construct a
cladogram
Organisms: Paramecium, flatworm, shark,
hawk, koala, camel, human
Characteristics: Eukaryotic, multicellular,
vertebral column, produces amniotic egg, has
hair, has placenta, has one opposable thumb
on each forelimb
Eukary
otic
Multice Vertebr Amniot Hair
llular
al
ic Egg
Colum
n
Placent Oppos
a
able
thumb
Totals
Parame
cium
+
X
X
X
X
X
X
1
Flatwor
m
+
+
X
X
X
X
X
2
Shark
+
+
+
X
X
X
X
3
Hawk
+
+
+
+
X
X
X
4
Koala
+
+
+
+
+
X
X
5
Camel
+
+
+
+
+
+
X
6
Human
+
+
+
+
+
+
+
7
Paramecium
Flatworm
Shark
Hawk
Koala
Camel
Hair
Multicellular
Human
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Cladistics attempts to find most logical and natural
connections between organisms by using morphological or
biochemical data
Classification shows connections by groupings organisms
into different taxa
Each time a derived characteristic is added to a cladogram,
it is similar to moving up one taxa in Linnaean System
Differences occur in organisms such as birds,
◦ Cladistics says birds share characteristics with dinosaurs and thus
are in the same clade
◦ Linnaean Classification have birds in a class of their own
Cladistics, rules are always the same concerning derived
and primitive characteristics
Classification definitions such as species, classes, and
phyla can be challenged
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
Use binomial nomenclature to name and classify
organisms
1st word refers to the genus, 2nd word to the
species, i.e. Homo Sapiens.
Carolus (Carl) Linnaeus consolidated and
popularized binomial nomenclature
Reasons:
◦
◦
◦
◦
Make sense of biosphere
Identify unknown organisms
Show evolutionary links
Predict characteristics shared by members of a group
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Five Kingdoms
◦ Kingdom Plantae (plants)
◦ Kingdom Animalia (animals)
◦ Kingdom Fungi (fungi and molds)
◦ Kingdom Protoctista (protozoa and algae)
◦ Kingdom Prokaryote (bacteria)
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Within each kingdom, there are several
subdivisions, called taxa
Seven-level hierarchy of taxa:
◦ Kingdom
◦ Phylum
◦ Class
◦ Order
◦ Family
◦ Genus
◦ Species
King Phillip Came Over For Good Soup
Taxa
Human
Garden Pea
Kingdom
Animalia
Plantae
Phylum
Chordata
Angiospermae
Class
Mammalia
Dicotyledoneae
Order
Primate
Rosales
Family
Hominidae
Papilionaceae
Genus
Homo
Pisum
Species
sapiens
sativum
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Feeding Habits (carnivore/herbivore)
Habitat (land dwelling/aquatic)
Daily activity (nocturnal/diurnal)
Risk (harmless/venomous)
Anatomy (vertebrates/invertebrates)
System of classification must be clear,
consistent, easily implemented and a general
consensus to apply it.
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Four of the several types of plant phyla
include:
◦ Bryophyta: short in stature such as moss
◦ Filicinophyta: ferns and horsetails
◦ Coniferophyta: coniferous, pine trees
cedar, juniper, fir
◦ Angiospermophyta: all plants that make
flowers and have seeds surrounded by
fruit
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Vegetative Characteristics such as leave types
and stems
◦ Bryophytes: non-vascular, lack vascular
transport tissue such as xylem or phloem
◦ Filicinophyta: vascular plants, small leaves
◦ Conifers: vascular, all produce woody
stems and leaves are needles or scales
◦ Angiosperms: vascular and have flowers
and fruit
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Reproductive characteristics
◦ Bryophytes: produce spores (microscopic
reproductive structures) transported by rain
water
◦ Filicinophytes: produce using spores in a
similar manner
◦ Conifer: use wind to help reproduce by
pollination, produce seed cones with seed
scales
◦ Angiosperms: produce seeds, rely on birds,
insects, and mammals to transport pollen.
Sexual organ is flower, fruit is enlarged ovary
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Six of many animal phyla include:
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All listed phyla are invertebrates
◦ Proifera: sponges
◦ Cnidaria: sea jellies (jellyfish), coral
polyps, and others
◦ Platyhelminthes: flatworms
◦ Annelida: segmented worms
◦ Mollusca: snails, clams, octopi, etc…
◦ Atrhtropoda: insects, spiders, crustaceans,
etc…
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Porifera:
◦ Simple marina animals that are sessile (stuck)
◦ Feed by pumping water through tissues and
filtering out food
◦ No muscle, nerve tissues, or internal organs
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Cnidaria:
◦ Very Diverse: Coral, sea anemones, jellyfish, hydra,
Portuguese man-of-war
◦ All have stinging cells called nematocysts
◦ Some sessile, some free swimming, some both
◦ Gastric pouch for digestion
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Platyhelminthes:
◦ Flatworms with one body cavity, gut with one
opening for food to enter and waste to leave
◦ No heart, no lungs
◦ Exchange gas by diffusion
◦ Example: Tapeworms
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Annelida:
◦ Segmented worms such as earthworms, leeches,
and polychaetes
◦ Bodies divided into sections separated by rings
◦ Have gastric tracts, w/ mouth at one end and anus
at opposite
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Mollusca:
◦ Aquatic animals, snails, clams, octopi
◦ Shell produced with calcium
◦ Non-segmented bodies
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Arthropoda:
◦ Hard exoskeleton made with chitin, segmented
bodies, and limbs (walking, swimming, eating)
◦ Insects, spiders, scorpions, crustaceans such as
crab and shrimp
◦ Live in most habitats throughout world
◦ Vary in size
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Used to help identify which order, genus, and species an
organism is by using observable characteristics
In General:
◦ Look at first section of key which has a pair of
sentences
◦ Look at the organism to see if particular
characteristics are present
◦ If answer is yes, to go end of line/next section that
contain a new pair of statements to examine
◦ If answer is no, go to second statement just below it
and follow that one, should it be true
◦ Continue this until the end of the line has a name, not
a number and if each question was answered
correctly, should be your organism.
Example in book, pg. 149
1. a. Organism is living........................................................go to 4.
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1. b. Organism is nonliving..................................................go to 2.
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2. a. Object is metallic........................................................go to 3.
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2. b. Object is nonmetallic..................................................ROCK.
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3. a. Object has wheels......................................................BICYCLE.
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3. b. Object does not have wheels......................................TIN CAN.
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4. a. Organism is microscopic...................................PARAMECIUM.
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4. b. Organism is macroscopic............................................go to 5.
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5. a. Organism is a plant.....................................................go to 6.
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5. b. Organism is an animal.................................................go to 8.
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6. a. Plant has a woody stem..............................................go to 7.
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6. b. Plant has a herbaceous stem.................................DANDELION.
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7. a. Tree has needle like leaves.....................................PINE TREE.
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7. b. Tree has broad leaves............................................OAK TREE.
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8. a. Organism lives on land................................................go to 9.
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8. b. Organism lives in water...............................................CLAM.
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9. a. Organism has 4 legs or fewer......................................go to 10.
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9. b. Organism has more than 4 legs...................................ANT.
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10 a. Organism has fur........................................................go to 11.
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10 b. Organism has feathers................................................ROBIN.
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11 a. Organism has hooves.................................................DEER.
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11 b. Organism has no hooves............................................MOUSE.
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Vocabulary can be challenging and technical
Make sure using the right key, no key can
identify all the species
Making a Dichotomous Key
◦ Start by putting things in groups by identical
characteristics
◦ Invent statements that divide things into created
groups
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List five kingdoms and determine where each
organism belongs: algae, hydra, spider,
mushroom, yeast, bacterium.
Design a dichotomous key using ten different
objects/organisms
In a population of 278 mice, 250 are black, 28
are brown. B=black, b=brown. Identify the allele
and genotype frequencies in this generation.
Spots for camouflage exist on many different
species, such as butterflies and cheetahs. A
student groups all organisms with spots in the
same clade. Is this justified? Why or why not?
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Plantae, Animalia, Fungi, Protoctista, and
Prokaryote
Algae – Protoctista
Hydra – Animalia
Spider – Animalia
Mushroom – Fungi
Yeast – Fungi
Bacterium - Prokaryote
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Answers may vary
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b = q = Square root of .10 = 0.32 = 32%
B = p = 1-.32 = 0.68 = 68%
bb = q2 = 28/278 = 0.10 = 10%
Bb = 2pq = 2(.68 x .32) = 0.44 = 44%
BB = q2 = 0.682 = 0.46 =46%