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.