Life in General

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Life in General

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Title: Life in General

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Life in General

Living matter is organized into complex
structures based on organic molecules. They have
cells.
Homeostasis is maintained by Living organisms.
Growth and development.
Reproduction and transmission of genetic
information. Living Organisms are capable of
replicating themselves and Continuing their
Genetic lines.

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Life in General (contd)

Acquisition and conversion of matter and energy
from the external environment. Living Organisms
are capable of integrating material from the
external environment and making it a part of
themselves. They are able to synthesize their
own organic materials
On this planet (at least) their is a requirement
for water.
Response to stimuli from the environment
Evolution.

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Classification Systems
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Classification Systems

classification is a method for organizing
information
ARISTOTLE (384-322 BC) is often called the father
of biological taxonomy.
His scheme referred to common groups, such as
birds, fishes, whales, and bats,
he recognized the need for groups and group names
in the study of animals.
his system was based on the knowledge that he
possessed at the time.

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Classification Systems (contd)

John Ray (1627-1705) used differences in anatomy
as the prime rule for classification, bringing
out both the similarities and differences between
groups--for example, fins or feathers.
This is still the preferred method

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Classification Systems (contd)

Similar things are grouped together.
However, there are many reasonable ways of
defining similarity, and as a result many
different classifications for the same things.

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Classification Systems (contd)

key property of classifications is that they can
be nested within one another, creating an ever
increasing leveled system.
As a result any group within a classification can
be split in still smaller groups .
There is no limit to the depth of a layered
classification.

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Carl Linnaeus

Linnaeus defined the biological classification
system that we still use for plants and animals,
and, with relatively minor changes, for fungi and
microorganisms.
It is a layered system that starts with a few
categories at the highest level, and further
subdivides them at each lower level.
In the Linnaean system, to uniquely name a
species it is necessary to supply both genus and
species.
In the case of animals, Linnaean classifications
often reflect our "gut reactions" regarding
whether an animal is similar or not.

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Linnaeus (contd)

biologists also classify organisms into different
categories mostly by judging the levels of
apparent similarity and difference that they can
see.
The assumption is that the greater the
similarity, the closer they are related in a
biological sense.

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Classifying Organisms

If an unknown organism is discovered, researchers
begin their classification by looking for
features that seem to have the same purpose as
those found on other species.
Next it will have to be determined whether or not
the similarities are due to a separate
evolutionary development or to a common ancestor.
If there is a common ancestor then the two
species are probably closely related and should
be classified into the same or near biological
categories.

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Classifying Organisms (contd)

Homologous structures are physical features, of
different organisms, that have a similar
appearance or function because they were
inherited from a common ancestor that also had
them.
For example, the forelimb of a sloth, the wing of
a crow, and your arm have the same functional
types of bones as did our shared reptilian
ancestor--these are homologous structures.
The more such structures two organisms possess,
the more likely it is that they have a close
relationship.

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Classifying Organisms (contd)

Listing features that separate one species from
another has the effect of making it look like the
species and their distinctive features are fixed
and eternal.
We need to remember that they were brought about
by evolutionary changes that operated not only at
some time in the past, but which also continue to
operate today and will surely give rise to new
forms in the future.
We also need to realize that most species are
genetically varied

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Biological Classification

Biological classification is the grouping of
organisms into categories that express their
PHYLOGENY, or line of descent, based on
information such as structure, development,
biochemical functions, and evolutionary history
of organisms.
The purpose of such a classification is to
provide a clear and practical way to organize and
communicate information about organisms.
Classification can show relationships between
different ancient and modern groups, indicate the
evolutionary pathways along which present-day
organisms may have developed, and provide a basis
for comparing experimental data about different
plant and animal groups.

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Biological Classification

Organisms included in a group share a common
genetic heritage in their genetic material, and
they must be more closely related to each other
than they are to the members of other groups of
the same rank.
However, classifications of organisms are
modified as new information comes forward and as
a result the phylogeny would change.
Taxonomy is the method we use to group organisms.
The first scheme for classifying animals into
logical groupings may have been brought forward
by Aristotle over 2,000 years ago.
Since then many new systems have been proposed
none, however, has succeeded in fitting all
plants, animals, and microorganisms into a
single, completely satisfactory scheme.

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Your Turn

Complete Investigation 4a page 110 -111

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Linnaeus

Over 200 years ago Carolus Linnaeus established
the first system for classifying species of
plants and animals.
He developed a categorical way of naming species
and a formal hierarchy for establishing larger
categories consisting of groups of species.
Linnaeus labeled each species with a Latin
double-name.
The species name for the brown trout, for
example, is Salmo trutta. The first word (with
initial letter always capitalized) designates the
genus (pl. genera).
Every species belongs to a genus that may also
include other species.
We can see from its name that the trout belongs
to the genus Salmo.

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Linnaeus (contd)

So does the closely related species Salmo Salar
(Atlantic Salmon).. The second word (which always
begins with a small letter) designates the
species.
A third word, indicating a sub-species may also
be used, e.g. Salmo trutta caspius - the Caspian
Sea Brown Trout.
The principle of gathering categories into more
specific groups is a fundamental aspect of
Linnaean classification.
The basic building block of classification is the
species.
A genus is a group of related species. Genera
are grouped in families, families into orders,
and so on.

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Linnaean Nomenclature

The standard nomenclature for species is
attributed to Carolus LINNAEUS (1707-1778).
The Linnaean method for classification of living
things groups organisms together based on
presumed similarities in structures.
The assumption is that the more structural
similarities the organisms in question share, the
closer they must be in terms of evolutionary
distance.

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Linnaean Nomenclature (contd)

The larger, more inclusive divisions of the
Linnaean system (beyond species) are created by
including together closely related groups of the
immediately lower divisions.
The result is a hierarchy of classification with
the highest category consisting of all living
things.
The lowest category consists of a single species.
Each of the categories above species can have
numerous subcategories.

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Linnaean Nomenclature (contd)

Linnaeus arranged classification categories as a
series of nested groups. His sequence from
broadest to smallest category is Kingdom,
Phylum, Class, Order, Family, Genus, and Species.
To remember this order you need only to remember
the following
King (Kingdom) Philip (Phylum) Came (Class) Over
(Order) For (Family) Good (Genus) Soup (Species)

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Linnaean Nomenclature (contd)

Related groups of organisms were determined by
the many shared characteristics especially those
having to do with maintenance, feeding, and
digestion.

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Linnaean Nomenclature (contd)

The basic unit in the Linnaean classification of
living forms is the species.
Each species is given a unique, two part Latin
name the name is always underlined or italicized
in print.
The name consists of the genus, which is a group
of species more closely related to one another
than to any other group, followed by the specific
name, which identifies a particular species
within a genus.
The first letter of the genus is capitalized,
while the specific name is in lowercase, as in
Felis domesticus (House Cat) and Salmo salar
(Atlantic Salmon).
The binomial species name replaced the much
longer descriptions of earlier classifications

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Linnaean Nomenclature (contd)

Linnaeus named groups of organisms for the
defining characters that he noticed.
For example, the name Mammalia to the group of
animals that possess mammary glands and secrete
milk to feed their young.
He also recognized that monkeys are most nearly
like humans, and as a logical consequence of
strictly biological classification, humans would
be grouped not only in the class Mammalia but in
the same representative group as the monkeys and
apes.
Today, the decision of which species to group in
a single genus is based on evolutionary
relationships - that is, a genus should be a
group of species all descended from a single
ancestral species.
Many biologists also consider overall anatomical
resemblance in addition to strict evolutionary
relatedness in making their classifications.

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DEFINITION OF A SPECIES

A Species is a group of populations that are
capable of successfully breeding and producing
fertile offspring.
Animals of one species, in other words, cannot
mate successfully with animals of another species
(or if they do mate and have offspring the
offspring are sterile) and it is this fact of
"reproductive isolation" that establishes them as
members of a separate species

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Binomial Nomenclature

In biology, binomial nomenclature is a standard
convention used for naming species.
As the word 'binomial' suggests, the scientific
name of a species is formed by the combination of
two terms the genus name and the species name
The first term (generic name) is always
capitalized, while the specific name (trivial
"name") is not both are to be typeset in
italics, e.g. Homo sapiens.
The genus name can be abbreviated to its initial
letter, but never omitted, (as H. sapiens) when
repeated or when several species from the same
genus are being listed or discussed in the same
paper or report.
In rare cases this abbreviation form has spread
to more general usefor example the bacterium,
Escherichia coli, is often referred to as just E.
coli.

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Binomial Nomenclature

The importance of a standard method of naming
living organisms becomes evident when you
consider the multitude of names that are used for
a single species as you move from locality to
locality.
Depending on where you live the term Green
Pepper, Bell Pepper, Sweet Pepper or Mango are
all used to describe the fruit Capsicum
frutescens.

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Binomial Nomenclature

Fish hawk
Osprey
(Pandion haliaetus)

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Your Turn

Find the proper scientific names for
Reindeer
Caribou
Labrador retriever
Gorilla
Human
Chihuhua

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Classification of Viruses

Are Virus's Living Things?
They are not classified as living organisms
because they do not have a cellular structure.
They do not have any of the structures that are
found in living cells.
They consist of strands of DNA or RNA surrounded
by a protein coat called a capsid.
What are They?
Viruss are little more than mobile genes that
infect cells and cause them to manufacture more
viruses.
The capsid protects the genetic material and
helps attach the virus to the host cell
Classifying Viruses
First observed in 1935.
More than 160 groups have been identified.
They are classified mainly by the types of
diseases they cause.
Different groups have different shapes.

Viral Shapes - Polyhedral
The Polio Virus responsible for Polio
T4 Phage that infects E.coli

Viral Shapes - Spherical
An example of the AIDS virus

Viral Shapes - Cylindrical
The tobacco mosaic virus

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Reproduction

Viruses reproduce by using other organisms.
They attach to the host cell and inject their DNA
into the cell.
Virus DNA causes the cells metabolism to
replicate more virus DNA
New viruses are replicated and eventually burst
out of the cell. When the cell membrane breaks
open it is often referred to as lyses.
Once it breaks open the host cell dies.

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Viral Diseases

There are a number of ways that viruses can
infect cells.
Retroviruses (RNA viruses) use an enzyme (reverse
transcriptase) to cause the host cell to copy the
viral RNA into DNA.
This new DNA instructs the cell to manufacture
more viruses.
Another method is for the viral DNA to be
incorporated into the host DNA.
It remains attached as the host cell goes through
many cell divisions until it eventually completed
its cycle.
While attached to the host cell it is called a
provirus.
Many diseases such as AIDS and cold sores can
remain inactive as proviruses until they are
triggered to complete their cycle.
People test positive for aids virus without
having the symptoms of the disease.
People who are susceptible to cold sores seem to
have them come and go at different times.

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Using Viruses

Useful pieces of genes can be copied by using
viruses as a vector.
The genes are combined with the virus DNA and
when they infect cells multiple copies of the
gene are made as the viruses replicate
The multiplied genes can then be harvested.

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Origin of Viruses

Viruses are composed of genes so therefore they
developed after cells.
It is believed that they originated as fragments
of genetic material that broke off from the
parent chromosome.
They survived as parasitic organisms on similar
types of cells.

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General Viral Information
Virus Cell
Structural Parts Protein, Nucleic Acid Core Nucleus, Cytoplasm, organelles, Membranes
Nucleic Acid Either DNA or RNA Both DNA and RNA
Reproduction Requires a Host Cell By Mitosis and Meiosis
Cellular Respiration No Yes
Cystallization Yes No
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Viruses non-living or alive?

A virus hijacks its host's cell machinery to
create more virus particles completing the life
cycle. It is the ultimate parasite!
Viruses are somewhere between the living and
non-living. They can reproduce and show
inheritance, but are dependent upon their hosts,
and in many ways can be treated like ordinary
molecules (they can be crystallized!).
Whether or not they are "alive", they are
obligate parasites, and have no form which can
reproduce independent of their host.
Like most parasites they have a specific host
range, sometimes specific to one species (or even
limited cell types of one species) and sometimes
more general.

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Your Turn

Read pgs. 122 126
Page 126 Questions 1,2,3,5

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6 methods that are utilized to classify
organisms.

Evidence from the Fossil Record
Often Fossils can be found that illustrate a
"Transition" from one species to another. When
such Transitions are made it suggests
commonalities between modern species.
Archaeopteryx when it was discovered suggested a
link between birds and reptiles.
Anatomical Evidence
Organisms that are anatomically similar are
likely to be related. The presence of Homologous
structures would suggest a reason to group
organisms together. The more similar species are
to one another the stronger the case for grouping
them together.
Embryological Similarity
As with the Anatomical Similarities the more
similar the organisms are during the
embryological stage the stronger the case for
grouping them together.

Biochemical Similarity
Again the more similar the Biochemical makeup of
the Species the stronger the case for grouping
them together
DNA Evidence
Once more a comparison of the DNA can be used to
classify organisms. The closer the DNA the closer
the relation and again the stronger the case for
a similar grouping.

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Modern Developments

The approach Linnaeus took to classifying species
and the majority of his taxonomic groupings
remained the standard in biology for at least two
centuries.
Since the 1960s, however, a trend called cladism
or cladistic taxonomy, has emerged and is
expected to usurp Linnaean classification.
In classifying species, cladists place a priority
in achieving unity with the Darwinian principle
of common descent.
In essence this method seeks to establish common
evolutionary patterns and group those that have a
common "ancestry" together.
This establishment of Phylogentic Relationships
can be said to be the 6th means for
classification.

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Cladistics

In grouping species, cladists look for "procured
similarities," meaning those aspects that species
can be expected to share by possessing a common
ancestor. This approach differs from that of
phenetics, which does not address ancestry and
associates species based on overall similarity.
It also differs also from classification based on
ad hoc "key characters." Cladists avail
themselves of all the types of evidence
available, including DNA sequences and
hybridization studies, biochemistry, and
traditional morphology.
They often make use of computerized algorithms
and mathematical formulae to identify the most
likely phylogeny or "family tree" that relates
the species they are considering.

The science of classification has grown as
knowledge and technology have grown. One leading
to the other. We now know far more than
Aristotle, Linnaeus, and other great Biologists
of the past could have hoped to know. Projecting
into the future our descendents will view our
knowledge base as we view theirs. Good for their
time but insufficient for ours!

As presented in the text Biologists by in large
have adopted a 6 Kingdom System of
classification. The reasons for this can be
distilled into an examination of the members of
the former Kingdom Monera (under the 5 Kingdom
System)
Within that group it was realized that there are
distinct differences between those that are known
as the Archae Bacteria and the remaining members.
For this reason the creation of a 6 Kingdom
arrangement was made.
This takes into account the unique differences
and satisfies the deficiencies that the 5 Kingdom
system held.

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Bacteria Archaea Eukarya Eukarya Eukarya Eukarya

Bacteria Archaea Protista Plantae Fungi Anamalia

Monera Monera Protista Plantae Fungi Anamalia
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Your Turn

Read pgs. 122 - 126
Page 127 Questions 2,3,4,5,6,7,8,9

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Question 2

Living matter is organized into complex
structures based on organic molecules. They have
cells.
Homeostasis is maintained by Living organisms.
Growth and development.
Reproduction and transmission of genetic
information. Living Organisms are capable of
replicating themselves and CAcquisition and
conversion of matter and energy from the external
environment. Living Organisms are capable of
integrating material from the external
environment and making it a part of themselves.
They are able to synthesize their own organic
materials
On this planet (at least) their is a requirement
for water.
Response to stimuli from the environment
Evolution.
ontinuing their Genetic lines.

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Question 3

Though both exhibit characteristics of living
organisms they do not have many other things (ie
cell walls, movement, etc)in common
Therefore, though they are classified a living
they are not considered to be closely related

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Questions 4

The classification system is a hierarchial
system, therefore, if two organisms are included
in a lower classification then they must also be
in the same higher taxa
Ie all members of a family are in the same order,
same class, same phylum and same kingdom

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Question 5

Though there are a number of different things
scientists consider when classifying organisms in
this instance the best indicator of relationships
would be the anatomical similarities
Horses and cows are adapted to be herbivores and
a wolf is a predator

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Question 6

Anatomical evidence
Biochemical evidence
DNA evidence
Phylogeny
Embryonic Development
Cladistics
Fossil records

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Question 7

On closer inspection wing structure is about the
only characteristic bats share with birds.
The underlying structure of the wing,
reproductive structures, evolution history, etc.
show that bats are not closely related to birds

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Question 8

The phylogeny is the evolutionary history of the
organism, it is believed that the closer in time
that two organisms are related the more
characteristics they will have in common
the further back in time they are related, the
less they will have in common

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Question 9

Though they do share one common characteristic,
scientists use much more that simply one
characteristic to classify organisms
They combine observations and evidence from a
variety of areas

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Characteristics of the Kingdoms
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Archaea

differ from the true bacteria in many important
respects, as well as from the eukaryotes. These
differences include
The wall structure and chemistry.
The lipids that make up the membrane
The metabolism
Many members of this kingdom are extremophiles
that is they live in extreme environments,
including water whose temperature exceeds that of
boiling water such as hot spring geysers and sub
sea vents.
They are very diverse, both in form and function.
Some are uni-cellular, while others form colonial
arrangements.

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Eubacteria

The eubacteria are microscopic and relatively
simple cells.
They lack the nucleus and organelles of the more
complex eukaryotes however, like the cells of
plants, most possess a cell wall.
After the "archae," true bacteria are the oldest
type of organism on Earth, and also the most
abundant.
They exist in soil, water, and as parasites of
other organisms.
Species and strains of bacteria cause many if not
most non-hereditary diseases.

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Protista

The Kingdom Protista or Protoctista is one of the
commonly recognized biological kingdoms. They
include all the eukaryotes except for the plants,
fungi, animals, and sometimes other groups which
are
treated in separate kingdoms. There are a few
forms that are multicellular, for example the
brown and red algae.
Most though are single-celled organisms, and are
typically only 0.01-0.5 mm in size, too small to
be seen without a microscope.
Protists are widespread throughout wet
environments and the soil.
Theyare able to survive dry periods by forming
cysts a few others are significant parasites.

Traditionally they have been separated into
Plant-like forms that contain chloroplasts, the
algae
Fungus-like forms, the slime molds and water
molds
Animal-like forms, the protozoa, generally
divided on the basis of structure These being
Flagellates (e.g. Euglena)
Amoeboids (e.g. Amoeba)
Apicomplexa
Ciliates (e.g. Paramecium)

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Fungi

The Fungi (singular fungus) are a large group of
organisms.
They include important decomposers and many
parasites.
Parasitic fungi infect animals, including us,
other mammals, birds, and insects, with results
varying from mild itching to death.
Other parasitic fungi infect plants, causing
disease such as Potato Blight.
Many vascular plants are associated with
mutualistic fungi, called mycorrhizae, which help
with the absorption of nutrients and water. Some
fungi are used as food, such as mushrooms and
truffles others are very poisonous and can cause
death if eaten.

Most fungi have vegetative bodies (called a
thallus or soma) that is made up of single
cell-thick filaments called hyphae.
Generally they do not merge into a visible
object, but instead form a microscopic network
within the substrate, called the mycelium,
through which food is absorbed.
The fungi are absorptive heterotrophs.
The more conspicuous parts of fungi like
mushrooms are fruiting bodies, reproductive
structures that produce spores.

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Plantae

This term is considerably more difficult to
define than we might think.
Our natural inclination is to regard plant as
meaning a multicellular, eukaryotic organism that
generally does not have sense organs or the
ability to move and has, when complete, a root,
stem, and leaves.
We have to acknowledge thought that only one
group, vascular plants, have "a root, stem, and
leaves".
Granted the more common plants that we encounter
on a daily basis would be the vascular ones.

Another, much broader (more inclusive) definition
for plant is that it refers to anything that is
photoautotrophic that is, it is able to make
its own food from light energy.
This is a reasonable definition, and one that
focuses on the role plants typically play in an
ecosystem.
Yet we must remember that there are
photoautotrophs among the Prokaryotes,
specifically photoautotrophic bacteria and
cyanophytes. These are often referred to as the
blue-green algae.

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Animalia

Animals are the group of organisms that make up
the kingdom Animalia.
Usually, they are multicellular and capable of
both locomotion and responding to their
surroundings.
Unlike plants, animals do not photosynthesize,
rather they consume their food they are
ingestive heterotrophs.

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Plant Groups

In order to begin to classify plants, consider
the structure by which the plant absorbs water.
Plants are either vascular or non-vascular.
Vascular plants have tube-like structures that
transport water from the roots to the stem to the
leaves.
Non-vascular plants absorb water only through
their surfaces.

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Non Vascular Plants

Non-vascular plants are plants that lack
water-conducting vessels in their tissue known as
tracheids.
Tracheids are located in the xylem, along with
wood vessels.
They are the most important water-conducting
vessels in seedless vascular plants and in
gymnosperms.

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Bryophytes

Bryophytes do not have a true vascular system and
are unable to pull water and nutrients up from
the ground at any significant distance.
Lacking this specialized system distinguishes
bryophytes from ferns and flowering plants. It is
for this reason that they are considered to be
rather primitive plants.
They are regarded as bridge between water plants
like algae and higher land plants like trees.
They are extremely dependent upon water for their
survival and reproduction and are usually found
in moist areas like steams and forest floors.
They first evolved about 500 million years ago
and were likely the earliest land plants.
The lack of vascular tissue limits their size,
generally keeping them under 12 centimeters high.
Roots are absent in bryophytes, rather there are
root-like structures known as rhizoids.

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Bryophytes (contd)

The word bryophyte refers to a group of plants
that includes the mosses, liverworts, and
hornworts. There are about 25,000 different
species.
Although small in size, they are one of the
largest groups of land plants and can be found
almost everywhere in the world.
There are more species of bryophytes than the
total number of conifer and fern species
combined.
A common example of the Bryophytes are Mosses.
Aside from lacking a vascular system, they have
a gametophyte-dominant life cycle, i.e. the
plant's cells are haploid for most of its life
cycle.
Sporophytes (i.e. the diploid body) are
short-lived and dependent on the gametophyte.

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Bryophytes (contd)

These plants do not flower and as a result never
produce seeds.
They reproduce by spore production
The process by which they produce spores is
termed alternation of generations.
Liverworts and mosses have been found in the
fossil record dating as far back as 300 million
years ago - the Paleozoic era. As a result of an
incomplete fossil record they are believed to
have shared a common ancestry with the green
algae.
Bryophytes have very distinct characteristics
that has allowed for the development of three
distinct classes - the Hepaticae (liverworts),
Anthocerotae (hornworts), and Musci (mosses).

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Tracheophytes (Vascular Plants)

The vascular plants have specialized transporting
cells xylem (for transporting water and mineral
nutrients) and phloem (for transporting sugars
from leaves to the rest of the plant).
When we think of plants we invariably picture
vascular plants.
Vascular plants tend to be larger and more
complex than bryophytes, and have a life cycle
where the sporophyte is more prominent than the
gametophyte

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Major evolutionary advances of the vascular
plants.
Advance Green Algae Bryophytes Tracheophytes
Development of the root-stem-leaf vascular system nonvascularized body (thallus) that may be variously shaped,no leaves, shoots, or roots no vascular system,leaflike structures are present, but lack any vascular tissue early vascular plants are naked, rootless vascularized stems,later vascular plants develop vascularized leaves, then roots
Reduction in the size of the gametophyte generation wide range of life cycles, some gametophyte dominant, others sporophyte dominant sporophyte generation dependant on gametophyte generation for food gametophyte is free-living and photosynthetic progressive reduction in size and complexity of the gametophyte generation, leading to its complete dependence on the sporophyte for food ,in angiosperms, 3 celled male gametophyte and a (usually) 8 celled female gametophyte
Development of seeds in some vascular plants no seeds no seeds seed plants retain the female gametophyte on the sporophyte
Spores/Pollen spores for resisting environmental degradation Spores that germinate into the gametophyte generation Spores that germinate into the gametophyte generation or spores that have the gametophyte generation develop within themselves
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Ferns

Ferns are a very ancient family of plants early
fern fossils have been found before the beginning
of the Mesozoic era, 360 million years ago.
They were thriving two hundred million years
before the flowering plants evolved.
As we know them now, most ferns are leafy plants
that grow in moist areas under forest canopy.
They are "vascular plants" with well-developed
internal vein structures that encourage the flow
of water and nutrients.
Unlike other vascular plants, where the adult
plant grows from the seed, ferns reproduce from
spores and an intermediate plant stage called a
gametophyte.

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Ferns (contd)

There are two main differences between the ferms
and other vascular plants.
The first is that ferns are delicate plants that
will only grow in areas which are moist.
They prefer sheltered areas on the forest floor,
near streams and other sources of permanent
moisture.
They cannot grow in hot dry areas like flowering
plants and conifers.
They do no have structures to prevent dessication
- drying out.

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Ferns (contd)

The second is linked to the first ferns
reproduce differently from the conifers and
flowering plants.
It all has to do with moisture. Not just the
moisture that allows the plant to live where it
does, but the moisture that allows it to
reproduce there. They have a more complicated
method that depends on there being liquid water
for the process to complete.
The sperm cell (male gamete must "swim" to the
egg).
As a result, they can only reproduce where there
is sufficient moisture reproduction requires
moisture.

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Higher plants have a very "tough" reproductive
system the pollen from the male flower is very
resilient, and the female flower nurtures the
seed until it is ready to grow.
The seeds themselves are able, because of their
structure, to wait for long periods in adverse
conditions before they grow.
So the higher vascular plants have evolved to
occupy nearly every place on the land surface of
the earth.

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Seed Plants

The seed plants are divided into two groups too.
These groups are the gymnosperms and the
angiosperms.
Gymnosperms are plants which produce seeds in
cones.
One well-known type of gymnosperm is the conifer,
which includes pine, fir and spruce trees.
In this province the Gymnoserms are our dominant
vegetation.
Angiosperms are plants which make their seeds in
flowers thus we call angiosperms flowering
plants.

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Gymnosperms have seeds but no fruits or flowers.
Gymnos means naked, sperm means seed in other
words gymnosperm equates to "naked seeds".
Gymnosperms developed during the Paleozoic Era
and became dominant during the early Mesozoic
Era.
There are over 700 living species that are placed
into four divisions. These being
Conifers,
Cycads,
Ginkgos, and
Gnetales

The largest, most widespread, and most familiar
group are the conifers, Division Coniferophyta,
that has about 550 species in 50 genera. T
hey include many familiar trees such as Douglas
firs, Black Spruce and White Spruce.
The other three Divisions of gymnosperms are much
smaller and rather obscure.
Division Cycadophyta contains about 140 species
of mainly tropical palm-like plants called
cycads.
Division Ginkgophyta contains but one species,
an 80 million-year-old evolutionary leftover
known as the maidenhair tree.
Finally, Division Gnetophyta contains about 70
species, some with some very odd characteristics.

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Cycads

Cycads retain some fern-like features, notably
their leaf shape.
Cycads were much more prominent in the forests
of the Mesozoic than they are today.
Presently, they are restricted to the tropics.

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Ginkgos

The ginkgos were also a much more prominent
group in the past than they are today.
The sole survivor of this once hardy and varied
group is Ginkgo biloba, the maidenhair tree.
Extensively used as an ornamental plant, Ginkgo
was thought extinct in the wild until it was
discovered growing natively in a remote area of
China.
Ginkos have separate male and female plants. The
males are more commonly planted since the females
produce seeds that have a harsh odor.
Pollination is by wind.
Recently, Ginkgo has become the current herbal
rave.

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Conifers

The conifers remain the major group of
gymnosperms.
In this province and other regions of the world
which possess similar climates and soil they are
the dominant tree type.
Their needle shaped leaves and other structures
allow for survival in this type of environment.

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Angiosperms

The angiosperms, were the last of the seed plant
groups to evolve, and appeared over 140 million
years ago during the later part of the of the Age
of Dinosaurs.
All Angiosperms produce flowers.
Within the female parts of the flower
angiosperms produce a diploid zygote and triploid
endosperm.
Fertilization is accomplished by a variety of
pollinators, including wind, animals, and water.
Two sperm are released into the female
gametophyte one fuses with the egg to produce
the zygote, the other helps form the nutritive
tissue known as endosperm.
The angiosperms produce modified leaves that are
grouped into flowers that in turn develop fruits
and seeds.

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There are approximately 230,000 known species.
Most have larger xylem cells known as vessels
that improve the efficiency of their vascular
systems.
The classical view of flowering plant evolution
suggests they developed from evergreen trees
that produced large Magnolia-like flowers.
Recent Fossil evidence though appears to
contradict this notion and a debate among
botanists has ensued.
Regardless of their origin though it is agreed
that the angiosperms underwent a significant
adaptive radiation during the Cretaceous, and for
the most part escaped the major extinctions that
occurred at the end of the period

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Invertebrates
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Invertebrates

The majority of animals on this planet are
invertebrates
32 of the 34 phyla of animals are invertebrates
Invertebrates lack a true defined backbone

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Characteristics of Animals

Symmetry - is the balanced distribution of
duplicate body parts or shapes. The body plans of
most multicellular organisms exhibit some form of
symmetry, either radial symmetry or bilateral
symmetry. A small minority exhibit no symmetry
(are asymmetric).
Body Cavity - (coelom) The cavity within the
body of all animals higher than the coelenterates
and certain primitive worms
Digestion
Reproduction

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Phylum Porifera

Sponges approx 5000 species
Aquatic organisms, usually marine
Usually irregularly shaped asymmetrical ( no
plane of division)
Filter feeders no true digestive system
Reproduction is asexual (budding) and sexual
Sexual fertilization is external - hermaphrodites
No true body cavity

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Phylum Cnidaria

Characterized by bodies that are radial
symmetrical
Aquatic organisms mostly marine
Bodies have a opening that has tentacles around
it
Digestion occurs in the opening by secreting
digestive juices into the cavity and absorbing
the nutrients
Reproduction is both sexual and asexual -
hermaphrodites
There is an opening but no body cavity
Sexual fertilization is external

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The two different forms of a Cnidarian body The two different forms of a Cnidarian body

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Phylum Platyhelminthes

Flatworms they have bilateral symmetry and show
signs of cephalization (head)
They have body tissues but do not have a true
body cavity
Single opening through which food enters and
waste exits - digestion is extracelluar
Asexual and sexual reproduction
Fertilization is internal hermaphrodites

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Phylum Nematoda