KINGDOM ANIMALIA Characteristics of Animals

Seven Levels of Taxonomic Classification Kingdom Phylum Class Order Family Genus Species Seven Levels of Taxonomic Classification

Seven Levels of Taxonomic Classification for the… Kingdom-Animalia Phylum-Chordata Class-Mammalia Order-Primates Family-Hominidae Genus-Homo Species-sapiens Seven Levels of Taxonomic Classification for the… Human

Seven Levels of Taxonomic Classification for the… Kingdom-Animalia Phylum-Chordata Class-Mammalia Order-Carnivora Family-Felidae Genus-Panthera Species-leo Seven Levels of Taxonomic Classification for the… Lion

Seven Levels of Taxonomic Classification for the… Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Xenarthra Family: Myrmecophagidae Genus Tamandua Species: tetradactyla Seven Levels of Taxonomic Classification for the… Collared Anteater

Seven Levels of Taxonomic Classification for the… Kingdom: Animalia Phylum: Cnidaria Class: Hydrozoa Order: Capitata Family: Milleporidae Genus: Millepora Species: alcicornis Seven Levels of Taxonomic Classification for the… Fire Coral

Animal Species Somewhere around 9 or 10 million species of animals inhabit the earth. About 800,000 species have been identified.

Animal Phyla Biologists recognize about 36 separate phyla within the Kingdom Animalia. Animal Phyla Web Page

Major Animal Phyla

Kingdom Animalia All animals are multicellular, mitochondrial heterotrophs—they have multiple cells with mitochondria and they rely on other organisms for their nourishment. Most animals ingest their food and then digest it in some kind of internal cavity.

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

Animal Movement Most animals are capable of complex and relatively rapid movement compared to plants and other organisms.

Animal Reproduction Most animals reproduce sexually, by means of differentiated haploid cells (eggs and sperm). Most animals are diploid, meaning that the cells of adults contain two copies of the genetic material.

Animal Sizes Animals range in size from no more than a few cells (like the mesozoans) to organisms weighing many tons (like the blue whale). a mesozoan blue whale

Animal Habitats Most animals inhabit the seas, with fewer in fresh water and even fewer on land.

Animal Cells Animal cells, like all eukaryotic cells, have internal structures called organelles that serve specific functions for the cell. Animal cells lack the rigid cell walls that characterize plant cells.

Animal Cell Diagram

Major Divisions Symmetry, Movement, & Cephalization Gastrulation & Gut Formation Dermal Tissues & Coelome Development Segmentation

Animal Bodies The bodies of most animals (all except sponges) are made up of cells organized into tissues. Each tissue is specialized to perform specific functions. In most animals, tissues are organized into even more specialized organs.

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

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

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

Animal Symmetry The most primitive animals are asymmetrical. Cnidarians and echinoderms are radially symmetrical. Most animals are bilaterally symmetrical.

Radial Symmetry …applies to forms that can be divided into similar halves by more than two planes passing through it. Animals with radial symmetry are usually sessile, free-floating, or weakly swimming.

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

Bilateral Symmetry Animals with bilateral symmetery are most well-suited for directional movement.

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

Radial vs. Bilateral Symmetry

Cephalization Bilateral Symmetry usually has led to cephalization—the process by which sensory organs and appendages became localized in the head end of animals.

Evolutionary Trends If we analyze the basic body plans of animals, we find that they illustrate evolutionary trends. Four major “advances” (in order): Multicellular body plan Bilaterally symmetrical body plan “Tube-within-a-tube” body plan Coelomate body plan

3 Major Bilateral Body Plans Acoelomates Pseudocoelomates Coelomates Each plan consists of 3 cell layers: endoderm, mesoderm, ectoderm

Acoelomate The coelome is a fluid filled cavity surrounded by mesodermal tissue Acoelomate animals lack a fluid filled cavity and are Triploblastic

Acoelomates These animals have no other cavity than the gut. They are often called the “solid worms.”

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)

Pseudocoelomates These animals have a body cavity (the pseudocoelom) which is not completely lined with mesoderm. The “tube within a tube” body plan. This category is also composed of mostly worms.

Coelomates These animals have a “true coelom” lined with mesodermal peritoneum. Most animals are coelomate.

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