Chapter 26 Introduction to the animal kingdom

1. Chapter 26 Introduction to the animal kingdom

2. What is an animal? • A. All heterotrophs • B. Multicellular • C. Eukaryotic cells • D. Do not have a cell wall • E. Bodies contain tissues • F. Contain epithelial tissue that covers the body • G. Muscle tissue • H. Connective tissue • I Nervous tissue

3. Invertebrate • Invertebrates – animals that do not have a back bone or vertebral column. • They range in size from microscopic to a giant squid size of 20 meters in length. • Groups – porifera, cnidarians, sea stars, worms, jelly fish, and arthropods. • Make up 95% of all animals on Earth.

4. Vertebrates Animals that all have a back bone and a vertebral column Makes up about 5% of all animals that include: Fishes, amphibians, reptiles, birds and mammals.

5. Survival techniques • Feeding – depending on what the animals eats, where it lives, its physical characteristics and surroundings will determine it’s feeding habits. Animals must ingest to receive energy necessary for sustain life. • Respiration – All animals, whether they live above or under water must take in Oxygen and give off Carbon Dioxide. Most of these animals contain complex tissues to perform this survival technique. • Circulation – a system of vessels that transport blood carrying oxygen and food to tissues and organs. It also removes waste and cleans the blood as it transport through the body. • Excretion – Animals that take in must release waste out of their bodies on a regular basis. Waste is toxic and must be removed or it will damage tissues.

6. Response – Specialized cells allow animals to respond to their environment for survival. • Movement – some have a sessile existence but most are motile and can move about. • Reproduction – Either through asexual or sexual, animals reproduce offspring in a variety of ways to instill the survival of their species.

7. Cell specialization and levels of organization • Early development stages: • Zygote • Blastula – hollow ball of cells that eventually become an elongated structure with a tail. This leads into a central tube that becomes the digestive tract formed one of 2 ways. • Protostome – animals whose mouth is formed from the blastopore, mostly invertebrates. • Deuterostome – animals whose anus is formed from the blastopore. • During early development the cells differentiate into 3 layers: • Endoderm – inner most germ layer that gives rise to the digestive tract and respiratory system. • Mesoderm – middle layer that gives rise to the excretory system. • Ectoderm – outer most layer that gives rise to the sense organs, nerves and the outer skin.

8. Body Symmetry • Radial symmetry – body parts that repeat around the center of the body, examples : sea star and sea anemone. • Bilateral symmetry – a single imaginary plane can divide the body into 2 equal halves. They have a left and a right side, usually a front and a back, upper and lower end. • Anterior – Front end • Posterior – Back end • Dorsal – Upper side • Ventral – Lower side • Cephalization – a concentration of sense organs and nerve cells at the front end of the body. Animals with this tend to respond more quickly and in more complex ways.