Science magnifies the Lord by examining the awesome beauty and complexity of His World in the light of His Word.

Characteristics of Animals

• All are multicellular eukaryotes• All are heterotrophic• Most are motile, (can move), at

least some part of life cycle• Most undergo a period of

embryonic development during which 2 or 3 layers of tissues form

What is an animal?

- Multicellular- Need water, food, and oxygen to survive- Heterotrophs

* Carnivores (Predators of Prey) (Eat other animals)

* Herbivores (Eat plants)* Omnivores (Eat plants and other animals)

The Nature of Animals (Kingdom Animalia)

• Invertebrates = 95% of all animals

• Vertebrate an animal with a backbone (5% of animals)

- Vertebrata is a subphylum of the phylum Chordata

- Vertebra one of the repeating bony units of the backbone

Animal DiversityAnimalia

- Invertebrata = (10 major phyla)

- Chordata = (11th major phylum)

* Vertebrata =

a subphylum

ElevenMajorAnimalPhyla

Symmetry & Body DirectionSymmetry & Body Direction

When studying and describing animals, some basic body characteristics are important. These include:

Animal Body SymmetryAnimal Body Symmetry - the way body parts are arranged around a center point. (Asymmetry, Bilateral Symmetry, Radial Symmetry)

Directions on the bodyDirections on the body - used to describe areas on the body of an animal. (Dorsal, Ventral, Anterior, Posterior)

Asymmetry = no symmetryAsymmetry = no symmetry

Bilateral and Radial SymmetryBilateral and Radial Symmetry

• CephalizationCephalization = concentration of nerve tissue and sensory organs at the anterior end of a bilateral organism

Dorsaltop surface

Anteriorfront end

Posteriorhind end

Ventralbottom surface

Directions on an animal body:Directions on an animal body:

 

Animal Tissue DevelopmentGerm tissue layers produce adult organs

–Endoderm = develops into gut lining

–Mesoderm = develops into muscles and internal body linings

–Ectoderm = develops into skin

Acoelomates:

The flatworm (planarian) is an acoelomate because it does not have a coelom within its mesoderm layer. Its

digesitive cavity is surrounded by the endodermal layer.

Pseudocoelomates:

Roundworms (Nematoda) and rotifers (Rotifera) have a body cavity (coelom) where organs are found and that can serve as a hydrostatic (fluid-filled) skeleton. Their coelom is called a pseudocoelom because it is not completely lined by mesoderm.

Coelomates: with a true coelom

Coelomates: with a true coelom

All complex animals have a true coelom, including the mollusks, annelids, arthropods, echinoderms and chordates. They have a true coelom that is completely lined by the mesoderm layer.The internal organs in a true coelom are more complex, and they are held in place by mesentaries. In other words, the coelom (white) is completely enclosed within the mesoderm layer (blue). Coelomates have more complex internal organs and a muscular gut (intestines) derived from the mesoderm.