CHAPTER 23: THE ANIMAL BODY 

Traits of all members of the Kingdom Animalia:

 

 

 

 

 

Body Plan – An animal’s overall structure

 

_______________________________________ - A process that favors changes in body plan that increase the likelihood of survival & reproduction.

 

The following Phylogenetic Tree (fig 23-2), page 438, illustrates the relationships among the major groups of animals:

 

 

 

 

 

 

 

 

 

 

The ____________________ of an animal reflects the way it lives, how it functions in its environment. Changes in body plan often result in different ______________________ and entirely ___________________________.

Each animal body plan is successful for a certain ___________________.

 

 

Phylum Porifera (The Sponges)

 

Key Evolutionary Features:

 

        _____________________________ (Cell Specialization)

This feature is an advantage because:

 

 

 

 

 

 

 

 

Refer to Fig 23-3, page 439, “Exploration of a Sponge”

 

 

 

 

 

 

 

Sponge displays __________________________, it has no definite shape.

 

Feeding Mechanism:

 

 

 

 

 

Choanocytes:

 

 

Pores:

 

 

Spicules:

 

 

Spongin:

 

 

Phylum Cnideria (Stinging-Celled Animals)

Ex: Jellyfish, Comb Jellies, Sea Anemone, Hydra

Key Evolutionary Features:

 

        ___________________________ - A group of similar cells that are organized into a functional unit. Cniderians have Specialized Tissues that make up the nervous, digestive, and reproductive systems.

        ___________________________ - Each layer of cells is a Tissue.

 

* __________________ - protective covering; contains ___________, or stinging harpoons

* __________________ - Releases digestive enzymes, absorbs nutrients (Extracellular Digestion)

        __________________________ - Allows animals to consume organisms larger than themselves.

        __________________________ - Body parts are arranged in a circle around a center point.

        ________ - Internal passage through which food passes while being digested.

Refer to “Exploration of a Cniderian,” page 440.

 

 

 

 

 

 

 

 

Gastrulation

 

 

___________________ - “Inner skin,” or inner tissue layer. This tissue layer becomes the ___________.

 

___________________ - “Outer skin,” or outer tissue layer. This tissue layer becomes the _______________ and _____________________________.

 

Refer to Fig. 23-5, page 441:

 

 

 

 

 

 

 

 

Phylum Platyhelminthes (Flatworms)

 Key Evolutionary Features:


         ___________________________ - Evolution of a definite head. This is characterized by concentration of sensory organs in the anterior end.

 

Advantages:

 

 

 

 

 

 

 

 

        _____________________________________ - An animal can be separated into nearly mirror-image halves by drawing an imaginary line lengthwise down the middle of the body.

        ___________________________ - (This is the THIRD tissue layer)

 

Organ:

 

Organ System:

 

 

Organs come from a ________________________, also called the _______________

 

In flatworms, _________________________ gives rise to _____ types of       _____________ layers:

Ectoderm = ______________________________________________

Mesoderm = _____________________________________________

Endoderm = _____________________________________________

 

Refer to Fig 23-7, page 443

 

 

 

 

 

 

 

 

Flatworms are ______________________, they do not have a body cavity. Their gut is completely surrounded by tissues & organs

 

Their body needs to be ________ to allow substances to pass easily to all organs.

 

Flatworms have a _____________________, meaning they only have ______ opening to the outside. 

        _______ is consumed and ________ are eliminated through the same opening

        This type of gut is less efficient at extracting nutrients than a ______________.

  

 

Refer to “Exploration of a Flatworm” on page 444:

 

 

 

 

 

 

 

Phylum Nematoda (Roundworms)

 Key Evolutionary Features:

 
        ___________________________ - Food is taken in through mouth -> nutrients are absorbed -> wastes are eliminated through anus.

 

Advantages:

 

 

 

 

 

 

Disadvantage:

 

 

 

        ___________________________ - “False Body Cavity” (It is real, but different from body cavities of other animals). It is a fluid-filled cavity between the gut and body wall, and separates the endoderm-lined gut from the rest of the body.

 

 

 

 

Refer to “Exploration of a Roundworm” page 445:

 

 

 

 

 

 

 

 

Phylum Mollusca

Ex: Snails, clams, oysters, scallops, mussels

 Key Evolutionary Features:

 
        ___________________________ - “True Body Cavity.” A fluid filled cavity that lies completely within the mesoderm. It separates the muscles of the body wall from muscles that surround the gut.

 

This is of Evolutionary importance because:

 

 

 

 

 

        _____________________________________ - A network of blood-carrying vessels that bring nutrients & oxygen to tissues, and removes excess wastes and CO2.

 

 

Refer to “Exploration of a Mollusk,” page 447.

 

 

 

 

 

 

 

 

Mantle:

 

 

Radula:

 

 

 

Phylum Annelida (Segmented Worms)

Key Evolutionary Features:

 
        ___________________________ - Repeated body units. Each segment of an earthworm has a complete set of ___________________________. An example of segments in humans is the ______________________________.

 

Advantage:

 

 

 

 

 

 

 

Refer to “Exploration of an Annelid” page 449.

 

 

 

 

 

 

 

 

Basic body plan of an earthworm is a “________________________________”

 

Setae:

 

 

 

 

Phylum Arthropoda 

Key Evolutionary Features:

 
        _____________________________________ - Limbs that project from the body.

 

Functions:

 

 

 

 

 

 

 

        _____________________________________ - An external skeleton made of ______________, a tough polysaccharide & protein. ________________ are attached to the inner surface of exoskeleton.

        ___________________________ - Has 2 (crayfish), 3 (insect), or many (millipede, caterpillar) segments.

 

Refer to “Exploration of an Arthropod” on page 450:

 

 

 

 

 

 

 

Most insects have ____ wings, _____ pairs of legs, and ____ body segments.

 

 

Two Patterns of Development

 Protostomes

 

 

 

 

 

 

 

Deuterostomes

 

 

  

 

Phylum Echinodermata (Echinoderms)
Ex: Starfish, Sand Dollars 

Key Evolutionary Features:

 
        ___________________________ - An internal skeleton.

        _____________________________________ (See above). This embryological evidence suggests that echinoderms are closely related to __________________________. All of the cells of the early embryo of these 2 phyla are _____________________.

        _____________________________________ as larvae, _____________________________________ as adults.

  

Refer to “Exploration of an Echinoderm” page 452:

 

 

 

 

 

 

Phylum Chordata
Ex: Lancelet, human

 All Chordates share these 4 key features:

 

 

  

 

 

 

Refer to “Exploration of a Lancelet” page 453:

 

 

 

 

 

 

Subphylum Vertebrata

Ex: Fish, amphibians, mammals, reptiles, etc.

 

 

 

 

 

Phylum Key Features Typical Organism
Porifera   Sponge
Cnideria  

 

Hydra
Platyhelminthes  

 

Liver Fluke, Planarian
Nematoda   Nematode
Mollusca   Snail
Annelida   Earthworm
Arthropoda  

 

Wasp
Echinodermata  

 

Sea Star
Chordata   Lancelet, Human

 

    

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