Download Characteristics to Classify Animals

KINGDOM: ANIMALIA
See Savage Science for an excellent series of lessons on animal evolution, here is the first one:
https://www.youtube.com/watch?v=Tvrs9jA3SP0
See also: https://www.youtube.com/watch?v=TQyO3AHKTrs
Characteristics to Classify Animals
1. Level of body organization
2. Number of tissue layers (germ layers)
3. Body Symmetry
4. Cephalization & Segmentation
5. Coelom
6. Protostome vs. Deuterostome
1. Level of Body Organization
 Although all animals are multi-cellular, they do not all possess
tissues, organs, or organ systems
 Members of some phyla possess bodies in which cells are only
poorly organized into tissues
 Members of other phyla have highly complex bodies in which cells,
tissues, and organs and organized into organ systems.
All animals, except sponges, are
composed of tissues. Tissues are
groups of specialized cells all
performing similar functions.
Epithelium, shown in this
illustration, is the tissue that lines
the respiratory
passages. Organs such as lungs
are composed of different types of
tissues: epithelial,
muscle, nerve, connective. Several
organs that operate together form
an organ system such as the
respiratory system.
2. Number of Body Layers (Germ Layers)
 Germ layers Mesoderm, ectoderm and endoderm tissues in animal
embryos soon after fertilization grow into every organ the animal needs
at birth
 Animals with radial symmetry, like cnidarians, produce two germ layers
(the ectoderm and endoderm) making them diploblastic.
 Animals with bilateral symmetry produce a third layer (the mesoderm),
between these two layers. making them triploblastic.
.
3. Body Symmetry
Asymmetrical : body shape is irregular eg. Sponges
 Bilateral Symmetry:
 Animals with bilateral symmetry have a "head" and "tail" (anterior vs.
posterior), front and back (dorsal vs. ventral), and right and left sides
 2 equal halves(not always mirror image) through only ONE vertical plane
For animals that swim, creep, run or move forward
 Bilateral symmetry enables effective movement in purposeful and
intentional directions for the animal, such as towards food sources or
better environments, or away from danger.
 Brain, sense organs are located in the front end.
 Most creatures we see around us have bilateral symmetry. Examples are
worms, insects, spiders, fish, birds and mammals, including humans
Radial Symmetry - Like Snowflakes or a Pie
An animal with radial symmetry could be divided into equal portions/haves
from the center, in the same way that you could cut a pie into wedges. An
animal with radial symmetry really has no right and left side or head and rear
end. Radial symmetry is ideal for animals that do not move, so they can reach
into their environment on all sides. Consider the starfish, hydra, as examples
of radial symmetry.
4. Segmentation;
 segmentation is the characteristic that the body is divided into repetitive
segments arranged on a longitudinal axis. Each segment contains parts
of the circulatory, digestive, nervous, and excretory systems. Annelids
are among the earliest organisms to appear with a segmented body
plan.
 Other organisms also have a segmented body plan. Arthropods, such as
insects, show a strong degree of segmentation with a head thorax and
abdomen with specific functions. Echinoderms, such as starfish, are also
segmented, but their segmentation is not along a longitudinal axis
because of their radial symmetry.
 Chordates, such as humans, are also segmented, but our segments are
so specialized that we barely notice it. On humans, the upper jaw, lower
jaw, the hyoid bone (found in the throat), vertebrae, and ribs are all
remnants of our segmented body form.
 Segmented organisms (arthropods, vertebrates, and annelids. ) can
move individual parts at different times. By allowing increased flexibility
of movement, segmentation permits more effective locomotion
 Unsegmented animals usually move their entire bodies all at once
Segmented body is like Cars in a Train
Bilateral and segmented body
5. Coelom
 Fluid-filled body cavity inside the mesoderm where digestive tract and other
organs are suspended for protection and cushioning
 Coelom begins to develop in the embryo
 In vertebrates, coelom is subdivided into separate cavities around the
heart, lungs and digestive tract
 Animals with coelom are worms/annelids,molluscs
 sponges, and flatworms are called acoelomates
MAIN CLASSIFICATION BREAKDOWN
Animals can be separated into 2 main groups
1. Chordates (vertebrates)
2. Non-chordata (invertebrates)
1. Non-chordates have the following phyla:
 Porifera (sponges)
 Cnidaria (jellyfish, hydras, sea anemones, Portuguese man-ofwars, and corals)
 Platyhelminthes (flatworms, including planaria, flukes, and
tapeworms)
 Nematoda (roundworms, including rotifers and nematodes)
 Mollusca (mollusks, including bivalves, snails and slugs, and
octopuses and squids)
 Annelida (segmented worms, including earthworms, leeches,
and marine worms)
 Echinodermata (including sea stars, sea cucumbers, sand
dollars, and sea urchins)
 Arthropods (including arachnids, crustaceans, millipedes,
centipedes, and insects)
2. Chordata are classified into vertebrates and non-vertebrates
1. Invertebrates
1. urochordates (tunicates)
2. cephalocordate (lancelets)
2. Vertebrates classified into agnatha and gnathostomata
1. Agnatha
1. lamprey and hagfish (scavengers or parasitic)
2. Gnathostomata
1. chondrichtymes (cartilaginous fish e.g. shark)
2. osteichthyes (e.g.bony fish)
3. amphibian (e.g. frogs, toads)
4. reptilian (e.g. snakes)
5. aves (e.g. birds)
6. mammals (e.g. humans)
Homework: State five characteristics of the following classes of vertebrata
Fish
Amphibia
Reptilia
Aves
Mammals
PARASITE MOVIE
http://www.dailymotion.com/video/x22szf1_infested-living-with-parasites2014-full-documentary_shortfilms