Objectives

Distinguish between 9 major phyla in the animal kingdom– Distinguish between kinds of symmetry– Distinguish between kinds of skeleton– Know the different levels of organization– Recognize segmentation

Symmetry

We’ll be differentiating between several phyla based upon symmetry. There are three kinds of body organization symmetry you must know.– First, what is symmetry?

Symmetry We’ll be differentiating between several phyla based

upon symmetry. There are three kinds of body organization symmetry you must know.– First, what is symmetry? Generally, a symmetric shape is

a shape that still looks the same if you fold or rotate it.

– Write down each definition, then, mold your play-doh into an organism that models that kind of symmetry.

– Check with me that you’re correct, then draw what you’ve made next to the definition.

Symmetry

Asymmetric: Irregular. Is not symmetric.

Create an asymmetric organism.– Check your work with me, then draw it.

Symmetry

Bilateral Symmetry: The organism can be divided into mirror-image halves.

Symmetry

Radial Symmetry: Cutting/folding down several planes would produce identical pieces. Radially symmetric organisms don’t have a lateral axis.

Symmetry

Real-life examples of the three kinds of symmetry?– Asymmetry– Bilateral symmetry– Radial symmetry

(Note: No organism is 100% perfectly symmetric, there are always “imperfections.” These describe the general body plan.)

Skeleton Types

Animal phyla are also divided by the type of skeleton involved.– Write the definitions. Then, together, see

if you can think of an animal that uses this kind of skeleton. Mold your clay into it.

Skeleton Types

Hydrostatic Skeleton: The organism does not have a “true” skeleton, it uses a fluid-filled cavity and/or fluid environment to maintain its shape.

Skeleton Types

Exoskeleton: The animal’s body is supported and its shape maintained by an external skeleton.

Skeleton Types

Endoskeleton: The animal’s body is supported and its shape maintained by an internal skeleton.

Levels of Organization

The most basic level of organization is a cell. The cell is the smallest self-contained unit that fulfills all the characteristics of life.– Animals are made of more than one cell.

However, they vary in the complexity of how those cells work together.

Levels of Organization A tissue is a group of cells that work together

to carry out a specific function. An organ is a group of tissues that work

together to carry out a general function. An organ system is a group of organs that

work together to carry out a major function.– Some organisms may have organ systems, others

may be simpler, some may not even have tissues.

http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/

Segmentation

Finally, you’ll need to know what segmentation is.

Segmentation is the division of a body plan into a series of semi-repetitive segments.– Please mold your play-doh into a body

plan showing segmentation.

Animal Phyla

I’ll teach you the general characteristics of 9 animal phyla. For each phylum:– Fill out your table with the characteristics of that

phylum Make note of what sets it apart from the other phyla You’ll later make a dichotomous key for use in

identifying animal phyla

– Mold your play-doh into an animal you think is representative of that phylum

Check with me to see if you’re right For every three phyla that you make a correct mold of

on the first try, you get a sticker.

Animal Phyla PORIFERA These sessile (non-moving) marine

animals are:– Asymmetrical– Lack true tissues, no organs or organ

systems– Not segmented– Hydrostatic skeletons– Reproduce sexually or asexually

(fragmentation)

Animal Phyla

PORIFERA– Sponges!

~8000 known speciesFirst emerged ~1 byaIncludes 3 classes

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Animal Phyla

CNIDARIA– These mostly motile (capable of

movement) marine animals are:Radially symmetricalHave tissues but not true organsNot segmentedHydrostatic skeletonsReproduce sexually or asexually“Mouths” surrounded by stinging tentacles

Animal Phyla

CNIDARIA– Jellyfish, sea anenomes, and corals!

More than 9000 speciesTwo-stage life cycle, medusa and polypFirst emerges 580 myaCharacteristic cnidocytes, stinging cells

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Animal Phyla PLATYHELMINTHES Motile, land- or water-dwelling animals that

are:– Bilaterally symmetrical– Have organs and a couple organ systems– Not segmented– Hydrostatic skeleton– Reproduce sexually– Have only one opening to/from their digestive

system

Animal Phyla

PLATYHELMINTHES Flatworms!

– More than 25,000 known species, most of which are parasitic

– Mostly hemaphroditic– No circulatory or respiratory system; they

are flat so that gases can diffuse to and from any cell in their body

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Animal Phyla NEMATODA Motile land- or water-dwelling animals

that are:– Bilaterally symmetrical– Have organ systems– Not segmented– Hydrostatic skeleton– Reproduce sexually– Have two digestive system openings

Animal Phyla NEMATODA Roundworms!

– More than 28,000 species described, estimated more than 500,000 species exist

– Over half are parasitic. Some parasitize animals, others parasitize plants.

– Includes C. elegans, a worm made of just 959 cells, one of the most important species to modern biology

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