The Kingdom Animalia:Unifying Characteristics

and Major Divisions

Unifying Characteristics

• Haploid Gametes• Embryonic Blastula Development• Diploid Somatic Cells • Multicellular Lacking Cell Walls• Mitochondrial Eukaryotes• Heterotrophic• Aerobic Respiring

Haploid Gametes

• In animals the adults produce haploid (having half the number of chromosomes) gametes through meiosis

The Embryonic Blastula

• After fertilization of an egg by sperm, the resulting diploid (having two pairs of chromosomes) zygote rapidly goes through mitosis

• All animals become a hollow sphere of cells called a blastula

Diploid Somatic Cells

• As the zygote develops the resulting body or somatic cells are diploid

Mitochondrial Eukaryotes

• Cells contain Mitochondria inside cells that carry on Cellular Respiration

• O2 + Glucose CO2 + H2O + ATP

Heterotrophic and Aerobic Respiring

• In order to acquire the Glucose necessary for cellular respiration animals must be consumers and eat organisms already containing glucose

• In order to acquire the Oxygen gas necessary for cellular respiration animals must have mechanisms of obtaining oxygen

Major Divisions

• Symmetry, Movement, & Cephalization

• Gastrulation & Gut Formation• Dermal Tissues & Coelome

Development• Segmentation

Radial Symmetry

• Body plan in which the body parts are arranged regularly around a central axis (multiple planes cut into mirror halves)

Bilateral Symmetry

• Body plan in which body parts are arranged into a left and right around a central plane (one plane cuts into mirror images)

• Cephalization results from this plan

Gastrulation & The Gut

• After the blastula stage, in some animals cells migrate to the interior forming the primitive gut

• In Protostomes the initial pore forms the mouth, while in the Deuterostomes this pore forms the anus

Tissue Organization: None

• Parazoan animals have specialized cells but lack the tissue level of organization

Diploblastic Tissues

• Tissue organization first appears in animals like jellyfish which are Diploblastic (having a distinct Ectoderm and Endoderm)

Coelome Development:Acoelomate

• The coelome is a fluid filled cavity surrounded by mesodermal tissue

• Acoelomate animals lack a fluid filled cavity and are Triploblastic

Pseudocoelomate

• Pseudocoelomate animals have a fluid filled cavity but it is not contained within mesoderm tissue. Instead it lies between the mesoderm and endoderm

• Pseudocoelomates are Triploblastic (having an Ectoderm, Endoderm, and Mesoderm)

Eucoelomate

• Eucoelomate animals have a true fluid filled cavity contained with in the mesoderm

• Eucoelomates are also Triploblastic

Segmentation

• Segmented organisms have a repeating series of body units that may or may not be similar to one another

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