Download The Animal Kingdom

The Animal Kingdom
Classification and Organization
Dr. Jim Whitfield
Basis of Classification
 What terms can we use to define what an animal is?
 As in, All animals are …..
Basis of Classification
 What terms can we use to define what an animal is?
 As in, “All animals are …..
 EUKARYOTIC
Basis of Classification
 What terms can we use to define what an animal is?
 As in, “All animals are …..
 EUKARYOTIC
 MULTICELLULAR
Basis of Classification
 What terms can we use to define what an animal is?
 As in, “All animals are …..
 EUKARYOTIC
 MULTICELLULAR
 HETEROTROPHS
What makes animals
different from each other?
 Animals differ in the arrangement of their cells
What makes animals
different from each other?
 Animals differ in the arrangement of their cells
 Animals differ in body symmetry (radial vs.
bilateral)
What makes animals
different from each other?
 Animals differ in the arrangement of their cells
 Animals differ in body symmetry (radial vs.
bilateral)
 Animals differ in the structure of the coelom
What makes animals
different from each other?
 Animals differ in the arrangement of their cells
 Animals differ in body symmetry (radial vs.
bilateral)
 Animals differ in the structure of the coelom
 Animals differ in the structure of such systems as
digestive, reproductive, circulatory, respiratory and
others
How do animals differ
when we classify them
according to the
organization of their cells?
Sponges (phyla: Porifera)
 Sponges exhibit basic cell organization
 The cells aggregate together, there is some
differentiation among function of the cells
 Their cells are mostly involved with obtaining food
and the exchange of oxygen and carbon dioxide
 This is known as “Cellular Organization”
 Sponges do not demonstrate symmetry
Jelly Fish and Coral Animals
(phyla: Cnidaria and Ctenophora)
 Your book uses the term COELENTERATES – this term
is no longer commonly used
 In these animals cells are organized to perform simple
functions including digestion, respiration and excretion
 A group of cells performing the same task is called a
tissue
 Hence these animals show tissue level of organization
 These animals show radial symmetry
Portuguese man o’ war
Note the radial
symmetry
Flatworms (Phyla:
Platyhelminthes)
 Flatworms are acoelomates?
 They are unsegmented invertebrates
 They are a simple digestive system with one
opening for eating and excretion – This is called an
incomplete digestive system
 These organisms are the first to show an organ level
of classification
Flatworms (Phyla:
Platyhelminthes)
 What do you think “Organ Level” of classification
means?
Flatworms (Phyla:
Platyhelminthes)
 Remember a group of cells that work together for a
common activity is called a tissue
 So a group of tissues that work together for a
common activity is called an organ
Flatworms (Phyla:
Platyhelminthes)
 More than half of all flatworms are parasitic –
meaning they cause disease. One of the most serious
diseases is Schistosomiasis (caused by the genus
trematode)
 This is the second most significant parasitic disease
worldwide after Malaria
 It is often called “Snail Fever” because snails serve
as the intermediate host
Higher animal groups
such as Annelids,
Arthropods, Mollusks,
Echinoderms, and
Chordates)
 Have pulled their organs together to form organ
systems
 Hence they demonstrate organ system level of
classification
 Each organ has a specific role
 The proper functioning of each is required for the
system to work properly
Differences in the Same
Systems
 Remember that platyhelminthes have an
incomplete digestive system, however from the
phyla Annelid onward have both a mouth and an
anus, hence they have a complete digestive system
 Some animals such as arthropods have an open
circulatory system – this means that the heart
pumps the blood directly into the body bathing the
cells – Chordates (you and I) have closed
circulatory system in which blood is pumped
though a series of arteries and veins
Symmetry
 As previously stated sponges are asymetrical – this
means that in whatever plane you cut them their
bodies will NOT be equal
 Jelly fish (Cnidaria) and star fish (Echinoderms)
show radial symmetry (like spokes on a wheel) this
means that you can cut the body in any plane and
have equal sides
 Higher animals show bilateral symmetry 0 this
means that the body can be cut in only one plane
and have equal left and right sides
Animals Can Also Be
Arranged by the
Arrangement of Their
Embryonic Cell Layers
Embryonic (Germinal)
Layers
 Animals whose cells are arranged into two
embryonic layers, an outer ectoderm and an inner
endoderm are called diploblastic
 Often an undifferentiated layer of cells is found
between these two layers and is called the mesoglia
 This type of arrangement is found in cnidarians
Embryonic (Germinal)
Layers
 Animals that have a third embryonic layer located
between the ectoderm and the mesoderm are called
triploblastic
 This layer of tissue is called the mesoderm
 Platyhelminthes to chordates are all triploblastic
What Becomes of these
Layers?
The Endoderm forms the stomach, intestines, lungs,
pancreas, bladder, trachea and thyroid gland
The Mesoderm forms the muscle, cartilage, urinary
tract (not including bladder), heat, spleen, dermis and
notochord
The Ectoderm forms the hiair, nails, lens of the eye,
sweat and sebacious glands, cornea, and the enamel of
the teeth