Ch 28.1

• What is an Animal?

?

Cnidaria: jelly fish, corals, sponges etc

• Chordata: sea squirts, lizards, fishes, humans. . .

• Nematoda: Roundworms

• Echinodermata: starfish, sea urchins, sea cucumbers . . .

• Platyhelminthes: planaria, tapeworm . .

• Annelida: segmented worms, leeches . .

• Fish

• Chordata: Vertabrata: dog, human . .

• Animal ?? » Yes.

All animals:

• Are multicellular• Feed on other organisms• Can move in some way to obtain food• Break down food to be used as energy or

building tissue.• Unlike plants, animals have no cell walls to

support the body.

Obtaining food:• Heterotrophic: They obtain energy and

nutrients from outside sources.– Move to find food: birds, humans . .– Draw food toward them: barnacles, sponges . .

Digest food:

• Internal: intestines: frogs, fish

• Intercellular: inside cells: sponges, flatworms

Development of Animals:

• Sperm finds egg

Zygote

• Sperm and egg are one object, one cell, ready to start multiplying.

In Humans:

In all animals:

See figure 28.51. Sperm and egg2. Zygote3. 2 cell4. 4 cell5. 8 cell6. Blastula: ball of cells7. Gastrula: infolding

Animal Body Plans:• Asymmetry: irregularly shaped

• Radial symmetry: left and right are equal if cut down ANY middle

• Bilateral symmetry: left and right from midline equals mirror image

Body plans for Bilateral symmetry:

• All have body cavities where internal organs are found.

1. Accept Acoelomates: flatworms: 3 cell layers w/ digestive tract but no body cavities.

• Pseudocoelomate: Roundworms: a Fluid-filled body cavity partly lined.

• Coelomate: Segmented worms, fish, lizards, humans, . . . Internal organs are in the open cavety (coelom)

Spinal cord

skin

Protection:

• Exoskeleton: hard outside

• Endoskeloton: support framework inside body.

Last slide

• Invertebrate: an animal w/out a backbone.

• Vertebrate: with a backbone

Quiz

• Tomorrow when you walk in on the information you just wrote down.

• Open note, open book.• Limited time per question.