Body Structure Quiz

Diploblastic organization

    -Diploblastic tissue organization is the simplest type of tissue organization

        -There is basically only two tissue levels in a diploblastic animal

        -The two layers are the

            -Ectoderm

            -Endoderm

        -In between these two layers is a Mesoglea which sometimes has cells and sometimes does not

            -The ectoderm gives rise to the epidermis and the endoderm gives rise to the gastrodermis

Sea Jellies are an example of a diploblastic animal

Triploblastic Organization

    -Triploblastic organisms have an extra tissue layer called a Mesoderm

        -The mesoderm gives rise to the organs

Coelom

    -A coelom is the space between the mesoderm and the gut

        -This space is where the organs rest

            There are three types of animals with coeloms

                -Acoelomate

                -Psudocoelomate

                -Coelomate

Invertebrates

    -97% of all species of animal on the planet are invertebrates

    -Almost all invertebrates have a marine representative

    -If it was not for the insects we would be able to say that the majority of animals are marine!

Phylum Porifera (Sponges) 8,000+ Species

Porifera Characteristics

        -The name Proifera translates as Pore Bearers

         -The phyla Porifera are the sea sponges

        Sea Sponges are:

        -Benthic - Live on the bottom of the sea

        -Sessile - Stuck to the bottom

        -Suspension Feeders - eat whats floating in the water

            -Filter Feeders - filter the water

        -Mostly Hermaphrodites - the make both sperm and egg

        -Broadcast spawning - Release sperm and eggs into the water where they fertilize on their own

        -Planktonic Larva - The larva float around in the water until they land somewhere and grow

        -Porifera Body structure

            -Asymmetrical - No symmetry 

            -Have three cell types

                -Pinacocytes

                -Mesenchyme cells

                -Choanocytes

            -They have a central cavity

            -They have no tissue or organs

    -Sponges have a rough skeleton made of silica spicules

        -There are some sponges however that have a soft calcium based spicule skeleton

        -This group is in the Genus Spongia

            -The sponges in the Genus Spongia are the ones that humans use as cleaning sponges

            -They were also used for many other things like, helmet padding, contraceptive, and painting

    -Sponges are one of the oldest animals still extant (not extinct)

    -They lived almost 500 million years ago

    -They are the simplest animal

        -They have no real muscles

        -No brain

        -No nervous system

    -It is hypothesized that they evolved from a colony of single celled protists similar to the choanoflagellida

        -A sponge's choanocytes strongly resemble the choanoflagellida

    -Sponges use their choanocytes (collar cells) to filter water

        -The collar cells move their flagella pumping water through the sponge

        -The sponge's cells feed on any particles that were in the water

    -Sea sponges are important to the ocean ecosystem because they filter and clean the water

    -Sea sponges also have amoebocytes

        -Cells that can move through the body of the sponge

There are three classes of Porifera

        -Class Calcarea

            -This class has spicules composed of calcium

        -Class Hexactinellida

            -This class has spicules composed of silica

            -Six rayed

            -Lattice, cup, or vase shape

        -Class Demospongiae

            -Brilliantly colored

            -needle shaped or four rayed spicules

            -Some are made of silica and some spongin

Sponges come in many shapes

    There are tube sponges 

Yellow Tube Sponge

    Barrel Sponges

Giant Barrel Sponge

    Vase Sponges

Pink Vase Sponge

    Rope Sponges

    Encrusting Sponges