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Biology May 6, 2013 Objectives: Intro into Animals Notes Assignment: Vocab Terms Grab notes sheet from side table! NEED BOOKS THIS WEEK!! Vocab Quiz Wednesday!!! Ch 23 Intro to Animals; Sponges & Cnidarians Chapter 26 Animal Characteristics 1. Heterotrophic (herbivores, carnivores, omnivores) - they depend upon other living things in the environment for food. 2. Multicellular - Different cells have different functions such as digesting food, getting rid of waste, reproduction, etc. (specialization) 3. Are eukaryotic = has a nucleus & membranebound organelles 4. No cell walls - Unlike plants, fungi, & bacteria Animal Classification Vertebrates have a backbone Invertebrates - don’t have a backbone,… -They make up 97% of all species (sponges, Cnidaria, flatworms, roundworms, mollusks, insects) What Animals Do to Survive - Many body functions help animals maintain homeostasis 1. Feeding 6. Movement 2. Respiration 7. Reproduction 3. Circulation 4. Excretion 5. Response 1. Feeding - Animals are heterotrophs, so they have to ingest food & digest the nutrients 2. Respiration - take in O2 & release CO2 3. Circulation - Moves materials around w/i their bodies - Some animals can rely on diffusion to move materials 4. Excretion - Most waste is ammonia (a poison to animals) - Is eliminated or converted to something less toxic & removed 5. Response - Nerve cells allow organisms to respond to their environment; not all org’s have nervous systems 6. Movement - Most animals move; with the help of muscles & skeleton - If they cannot move; have adaptations that allow them to meet their needs 7. Reproduction - Most reproduce sexually - Some can also reproduce asexually BODY SYMMETRY 1.Asymmetrical – no pattern 2. Radial Symmetry – an axis (circle around a central point) 3. Bilateral – 2 sides which are a left & right side that mirror each other anterior – front end posterior – rear end dorsal – back or top ventral - belly *Note: animals in a group have similar characteristics because they have similar evolutionary histories. Cephalization: concentration of sense organs & nerve cells at the front end of the body -org’s w/ cephalization react to environment quickly & in complex ways - the more complex organisms have more complex cephalization (bigger brains) -Most animals also have a body cavity: a fluid-filled space that lies between the digestive tract & the body wall -- provides a place for internal organs Assignment Look up Vocab Terms. If they are not in your book they are in your notes! You should find ALL WORDS!! QUIZ WEDNESDAY! SPONGES!! PHYLUM PORIFERA “Pores” • Least complex animals • Simple body plans • No body tissues, organs, or systems Characteristics •Live in water (mostly salt water) •Many shapes, sizes, colors • Most are asymmetrical (a few radial) • Adult sponges are sessile = don’t move • Often found in colonies Obtaining Food • Food is filtered out of the water = filter feeding • Choanocytes (collar cells) pull the water thru the ostia (pores) • have flagella that help move water thru bringing in O2 & carrying away wastes (leaves via osculum (hole at top) Choanocyte (Collar cells) The movement of water thru the sponge provides a simple mechanism for feeding, respiration, circulation, and excretion. ostia Sponge Bodies • May contain a “skeleton” of: 1. Spicules – sharp & pointed, often made of silicon or calcium 2. Spongin – fibrous material 3. Both spicules & spongin Reproduction • Sponges can reproduce asexually and sexually I’m a chip off the old block! 1) Asexual –producing buds –regeneration (growth) of missing parts 2) Sexually • joining of egg and sperm • Most are hermaphrodites can produce both eggs and sperm Sexual Reproduction Phylum: Cnidaria Cnidarians (Stinging celled animals) • Ex: coral (live in colonies), sea anemone, jellyfish, hydra (freshwater, live in colonies) Jellyfish JELLYFISH Characteristics • Live individually except coral & hydra • Coral live as a colony of polyps covered by calcium carbonate (polyps join together to form a coral reef) • Live in salt water except hydra •Radially symmetrical •Have 2 cell layers, tissues, & a digestive cavity •Arm-like tentacles surround mouth (tentacles contain stinging cells used to capture food & to protect) •Stinging cells (cnidocytes) contain a capsule which explodes & shoots out a thread w/poison (nematocysts) - prey is paralyzed by the poison & the tentacles pull it back to the body into the mouth 2 Body Plans • Polyp – vaselike • Sessile • Hydra, sea anemone • Medusa – bell shaped • Free swimming • Jellyfish Reproduction Medusa • Have both sexual & asexual stages to complete the cycle • Sexually for freeswimming Polyps • Fertilized eggs become the larva • Asexually by • Larva settle & form buds which fall polyp off parent • Asexually when • Sexually w/egg young medusa bud & break off & sperm - have a nerve net that connects all parts of organism. - Allows for simple responses & movement. CORAL • Found in warm tropical seas between 30o north & 30o south latitude • Many sea anemones attach to dead coral • Reef is composed of a base of dead coral cemented together & living coral at surface • Help protect beaches & shorelines/used for recreation (diving, snorkeling)