Kingdom Animalia Major Animal Phyla Porifera Cnidaria Phatyhelminthes Nematoda Rotifera Mollusca Annelida Arthropoda Echinodermata Chordata

Major Chordata classes Agnatha Chondrichthyes Ostiechthyes Amphibian Reptilia Aves Mammalia

Major Mammalia Orders Monotremes Marsupials Placentals

Essential Functions of Animal Life Feeding (Digestive system) Respiration (Respiratory system) Internal transport (Circulatory system) Excretion (Excretory system) Response (Nervous sysytem) Movement (Skeletal/ Muscular sysytem)

Kingdom Animalia All animals are multicellular. All animals are heterotrophic. Dominant generation in the life cycle is the diploid generation. Most animals are motile during at least some part of their life cycle. Most animals undergo a period of embryonic development during which two or three layers of tissues form.

Animal Diversity variations in the following characteristics Tissue complexity – Eumetazoa- cells organized into tissues Three germ layers –Ectoderm- outer layer –Mesoderm- middle layer –Endoderm- inner layer Diploblastic- two germ layers Triploblastic- three germ layers – Parazoa- cells are not organized into true tissues and organs do not develop.

Embryonic Development Fertilization Cleavage – Zygote begins a series of cleavage divisions, rapid cell divisions without cell growth. – Blastomeres = resulting cells Morula= solid ball of cells from successive cleavage divisions Blastula= liquid fills the morula creating a hollow sphere of cells. – Cavity is called blastocoel.

Embryonic Development Gastrula (gastrulation) – Occurs when a group of cells move inward into the blastula. – Forming a two-layer embryo with an opening from the outside into a center cavity – Third layer forms between the outer layer and inner layer. Ectoderm, mesoderm, endoderm

Embryonic Development – Archenteron Center cavity formed by gastrulation Completely surrounded by endoderm cells – Blastopore Opening into the archenteron It becomes the mouth in protostomes It becomes the anus in deutrostomes

Embryonic Development Extraembryonic membrane development – In birds, reptiles, and mammals – Chorion – outer membrane Birds & reptiles it acts as a membrane for gas exchange Mammals- it implants into the endometrium and later together with maternal tissue, forms the placenta. –Placenta- gases, nutrients, and wastes are exchanged

Embryonic Development – Amnion- encloses the amniotic cavity, a fluid- filled cavity that cushions the developing embryo. – Yolk sac- birds and reptiles Membrane that digests the enclosed yolk Blood vessels transfer the nutrients to the developing embryo

Embryonic Development Organogenesis – Cells continue to divide after gastrulation and start to differentiation (cell differentiation) – Development of organs is organogenesis. – Chordate characteristics Notochord- stiff rod that provide support in lower chordates –Cells along the dorsal surface of the mesoderm germ layer form the notochord. –In higher chordates, the vertebrea are formed from nearby cells in the mesoderm Neural tube- formed from ectodermal cells directly above the notochord –Neural plate is formed first, indents forming the neural groove, then rolls up into a cylinder, the neural tube. –The neural tube develops into the Central nervous System

Embryonic Development Ectoderm – Skin, Nervous system, Teeth, Bones Endoderm – Digestive tract and organs derived from it, such as the liver and lungs of vertebrates Mesoderm – Muscles and most other organs between the digestive tube and the outer covering of the animal

Animal Diversity variations in the following characteristics Body Symmetry – Radial symmetry Only one orientation –Front and Back or Top and Bottom Circular body patterns – Bilateral symmetry Dorsal (top) Ventral (bottom) Anterior (head) Posterior (tail)

Animal Diversity variations in the following characteristics Cephalization – A progressively greater increase in nerve tissue concentration at the anterior end (head) as organisms increase in complexity – Example Brains have developed with accessory sensory organs for seeing, smelling, tasting, and feeling.

Animal Diversity variations in the following characteristics Gastrovascular cavity – Areas where food is digested – One opening – Two openings Digestive tract

Animal Diversity variations in the following characteristics Coelom – A fluid-filled cavity that develops from mesodermal tissue during embryonic development in more advanced animals. – Cushions the internal organs and allows for their expansion and contraction. – Acoelomate- lack a coelom – Pseudocoelomate- cavity that is not completely lined by mesoderm-derived tissue.

Animal Diversity variations in the following characteristics Segmentation – Segmented body parts

Animal Diversity variations in the following characteristics CharacteristicsProtostomeDeuterostome Early cleavagesSlight angle (spiral cleavage) Straight down (radial cleavage) First infolding of archenteron forms mouthanus Coelom develops from Split in tissue at sides of anchenteron Outpounching of archenteron wall