animal symmetry by L75o9l

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									 Bell Ringer 01/10/11
  Write down the following terms and definitions on
              your Bell Ringer sheet.

1. Symmetry: the balanced arrangement of body
   parts
2. Porifera: the phylum within the animal kingdom to
   which sponges belong
3. Cnidaria: the phylum within the animal kingdom to
   which jellyfish, hydras, and sea anemones belong

        **HAVE OUT YOUR TAKE-HOME QUIZ**
Today…
• Essential Question: What is symmetry and what
 types are found in the animal kingdom?

• Objective: After viewing a PPT about symmetry,
 students will be able to describe the type of
 symmetry found in several specimens by
 completing a chart with at least 80% accuracy.
What we’ll look at specifically
• Definition of the two types of symmetry
  (radial and bilateral)
• Definition of no symmetry
• The Animal Kingdom
 • Each of the distinct phyla
So what is symmetry?
• Symmetry in biology is “the balanced distribution
 of duplicate body parts or shapes.”

• The body plans of most organisms show some
 form of symmetry, either radial symmetry or
 bilaterial symmetry.

• Only a small minority exhibit no symmetry (are
 asymmetric)
                  • Definition: having many
Radial symmetry    equally-spaced lines that
                   pass through a central
                   point
                   Many planes of symmetry
                     • Definition: body
Bilateral symmetry    plan with two
                      halves that are
                      mirror images
                     Only one plane of
                     symmetry
No symmetry aka “Asymmetric”
• Definition: body plan with no planes of symmetry
• The simplest animals (sponges) are asymmetrical.
Quick Check
• What symmetry do these animals have?
Review of Symmetry
           The Animal Kingdom
• The animal kingdom is the last of the six kingdoms
  we will learn about
• Because there are so many different kinds of
  animals, the kingdom is broken down into distinct
  phyla to help categorize

• Remember the classification system we learned in
  class
• Kingdom  Phylum  Class  Order  Family 
  Genus  Species
9 Phyla of the Animal Kingdom…
• Porifera          Chordata
• Cnidaria
• Annelida
• Nematoda
• Platyhelminthes
• Mollusca
• Echinodermata
• Arthropoda
                  Porifera
• Sponges
• Have many pores, sessile (non-moving), filter-
  feeders
• Only phylum with NO symmetry
                 Cnidaria
• Jellyfish, sea anemones, hydras, coral
• Jelly-like animals that have a bell or
  umbrella shape
• Radial symmetry
               Annelida
• Segmented worms
• Long animals divided into segments
• Bilateral symmetry
                  Nematoda
• Roundworms
• Worms that are parasites
• Body symmetry: bilateral
              Platyhelminthes
• Flatworms
• Soft, thin, flat bodies
• Body symmetry: bilateral
                   Mollusca
• Bivalves, cephalapods, gastropods
• Body symmetry: bilateral and radial
• Soft-bodied animals, usually have a shell
                  Echinodermata
• Sea stars, brittle stars
• These marine animals have plates with spines
• Exhibit radial symmetry
                 Arthropoda
• Insects, crustaceans, arachnids, millipedes and
  centipedes
• They have three body parts, jointed legs, and a
  tough exoskeleton
• Bilateral symmetry
                  Chordata
• Vertebrate animals
• Animals that have a notochord that supports the
  body (a backbone)
• Body symmetry: bilateral
            Time to practice
• In your science notebook, you are going to be
 drawing detailed sketches of various specimens
 at your lab station.

• You must include the following:

1. Label the organism
2. Sketch the organism
3. Draw the plane(s) of symmetry and identify
   what kind of symmetry the animal has (radial,
   bilateral, or asymmetrical)
     Draw a chart like this. Leave room for
              more organisms

     Organism        Phylum      Symmetry
1. Crayfish

                    Arthropoda    Bilateral


2.
    REVIEW – what kind of symmetry?

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