Zoology.docx

**NATSCI133 ZOOLOGY -- AN INTRODUCTION** **ZOOLOGY** - Study of animals - In this class -- important kingdoms **Protista**: some animal-like organisms considered to be evolutionary precursors to animals **Animalia**: are animals **KINGDOM PROTISTA** - Single celled - Euka...

**NATSCI133 ZOOLOGY -- AN INTRODUCTION** **ZOOLOGY** - Study of animals - In this class -- important kingdoms **Protista**: some animal-like organisms considered to be evolutionary precursors to animals **Animalia**: are animals **KINGDOM PROTISTA** - Single celled - Eukaryotic - Ingest or produce food - Some animal-like **WHAT IS AN ANIMAL?** - Are members of Kingdom Animalia - Are **multicellular**: having more than one cell - Are **eukaryotic**: organisms whose cell contain a nucleus - Are **heterotrophs**: organisms that obtain energy from the foods it consumes; also called a **consumer** - Lack cell walls - Usually have a method of movement - Most reproduce sexually - Require oxygen +-----------------------------------+-----------------------------------+ | **IMPORTANT LATIN ROOTS** | | +===================================+===================================+ | - **Cyte** = cell | - **Taxon** = unit | | | | | - **Zoa or zoo** = animal | - **Nomen** = name | | | | | - **Demo** = people | - **Clature** = system | | | | | - **Epi** = on or on top | - **Pori** = pore | | | | | - **Coel** = cavity | - **Fera** = to have or bear | | | | | - **Oid** = like | - **Cephala** = head | | | | | - **Ation** = to form | - **Homologous** = similar in | | | origin | +-----------------------------------+-----------------------------------+ **PHYLOGENETIC TREE OF KINGDOM ANIMALIA** **2 TYPES OF ANIMALS** **Invertebrates**: Animals that do not have a backbone or a vertebral column **Vertebrates**: Animals that have a vertebral column, or backbone **WHAT ANIMALS DO TO SURVIVE** Animals carry out the following essential functions: 1. Feed 2. Respire 3. Circulation 4. Excrete 5. Respond 6. Move 7. Reproduce **ESSENTIAL FUNCTIONS** 1. **FEEDING**: animals feed in a large variety of ways - **Carnivore**: Eats meat ONLY - **Herbivore**: Eats plants ONLY - **Omnivore**: Eats meat and plants - **Detritivore**: Feeds on plant and animal remains and other dead matter called **detritus** (includes poop) - **Mutualism**: Symbiotic relationship in which both species benefit from the relationship. Example: career crab - **Commensalism**: Symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed. Example: barnacles on whale - **Parasitism**: Symbiotic relationship in which one organism lives in or on another organism and harms it. Example: lice 2. **RESPIRATION**: Whether they live in water or on land, all animals respire, which means they take in oxygen and give off carbon dioxide. - Some can rely on diffusion of these substances through their skin - Most have evolved complex tissues and organ systems for respiration 3. **CIRCULATION**: Many aquatic animals (ex. aquatic worms) rely solely on diffusion to transport oxygen and waste. - Larger animals have some kind of circulatory system to move materials around within their bodies. 4. **EXCRETION**: A primary waste product of cellular metabolism is **ammonia**, a poisonous substance that contains nitrogen. - A buildup of ammonia and other wastes would kill an animal - Animals have excretory system that either eliminates ammonia quickly or converts it into a less toxic substance that is removed from the body. 5. **RESPONSE**: Animals respond to events in their environment using specials cells called **nerve cells**. - Nerve cells hook up together to form a nervous system - Some nerve cells are receptors that respond to sound, light, and other stimuli - The arrangement of nerve cells in the body changes dramatically from phylum to phylum 6. **MOVEMENT**: Some live their entire lives attached to a single spot. - Most are **motile**, meaning that they move 7. **REPRODUCTION**: Most reproduce **sexually** by producing gametes. - Maintains genetic diversity in populations - Helps species evolve when the environment changes - Many reproduce **asexually** and allows to increase numbers rapidly (inverts.) **DESCRIBE THE BODY PLANS OF ANIMALS** 1. **SYMMETRY**: balance in body proportions - **Asymmetrical**: irregular shape. Has no definite shape. - **Radial** **Symmetry**: can be divided along any plane to produce 2 halves which look alike. Body is arranged in a circle like the spokes of a wheel. - **Bilateral Symmetry**: can be divided only one way to produce mirror image halves. If divided lengthwise in half, both sides will match. - Includes worms, insects and vertebrates. - Have external body parts that repeat on either side of the body. - **Anterior End** = Front End - **Posterior End** = Back End - **Dorsal Side** = Upper Side - **Ventral Side** = Lower Side 2. **BODY ARRANGEMENTS:** - **Anterior**: head region (front on upright man) - **Posterior**: tail region (back on upright man) - **Dorsal**: back or top - **Ventral**: abdomen (belly) or bottom - **Medial**: close to the middle - **Lateral**: close to the side or movement away from middle - **Distal**: away from the main part - **Proximal**: close to the main part - **Oral:** end with the mouth - **Aboral**: opposite end of the mouth - **Cephalic**: toward head - **Caudal**: toward tail 3. **BODY DEVELOPMENT** As an embryo develops, three germ layers form: - **Ectoderm**: becomes nervous system, epidermis of the skin, pituitary, lens of eye - **Mesoderm**: becomes muscles, skeleton, notochord, circulatory system, kidney, reproductive system - **Endoderm**: becomes lining of digestive tract, liver, pancreas, epithelial lining of lungs, many endocrine glands 4. **BODY CAVITIES** - **Acoelomates**: no body cavity lined with mesoderm Example: sponges, cnidarians, flatworms - **Pseudocoelomates**: partial body cavity lined with mesoderm "Tube within a tube" body plan Example: roundworms - **Coelomates**: true body cavity lined with mesoderm Example: all other animals **Advantages of a body cavity (coelom or pseudocoelom):** - Fluid in cavity helps distribute food, wastes, hormones, etc. from one end of animal to the other - Better distribution allows animal to grow larger - A place to put things, like new organs 5. **CEPHALIZATION**: concentration of sense organs; developed nervous system **Invertebrates**: no backbone **Vertebrates or chordates**: backbone **PROTOSTOMES VS. DEUTEROSTOMES** Zygote cleaves to become blastula and then forms gastrula. The **blastopore** of the gastrula can become either the mouth or the anus of the organism. - **Protostomes**: blastopore becomes mouth Ex. annelids, mollusks and arthropods - **Deuterostomes:** blastopore becomes anus Ex. chordates