1 / 49

Lower Invertebrate: Introduction to Animals

Lower Invertebrate: Introduction to Animals. Whats an Animal?. So lets think about this for a second, what really makes an animal an animal? What differentiates it from a plant, fungi or bacteria? Are there any grey areas? Pollination http://www.youtube.com/watch?v=MQiszdkOwuU&feature=related

xannon
Download Presentation

Lower Invertebrate: Introduction to Animals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lower Invertebrate: Introduction to Animals

  2. Whats an Animal? So lets think about this for a second, what really makes an animal an animal? What differentiates it from a plant, fungi or bacteria? Are there any grey areas? Pollination http://www.youtube.com/watch?v=MQiszdkOwuU&feature=related Moving Art http://www.youtube.com/watch?v=xQXaap6owZE&feature=fvsr

  3. Animal Characteristics Animals are characteristically multicellular heterotrophs (INGESTION). This process of obtaining food requires the most the most thought, behaviors, responses and techniques. This makes animals more comlex. whose cells lack cell walls. At some point during their lives, animals are capable of movement (motile). In the most commonly encountered animals, this stage is the adult, although some animals (corals) have sessile (nonmobile) adult phases and mobile juvenile forms. Animals developed external or internal skeletons to provide support, skin to prevent or lessen water loss, muscles that allowed them to move in search of food, brains and nervous systems for integration of stimuli, and internal digestive systems.

  4. Phylogenetic Tree of Animals Over the next three chapters we will fly through 9 different phylum of animals in increasing complexities of body plans and life cycles.

  5. Body Break. Major divisions in the animal kingdom are based on body plans. Most bodies display some level of symmetry. Most well known show BILATERAL SYMMETRY, which is where you have a left and right half. Animals like starfish show more than one plane of symmetry display RADIAL SYMMETRY Most basic show an asymmetrical body plan

  6. Bilateral vs. Radial

  7. Direction Anterior (Head), Posterior (Anus). Dorsal (top), Ventral (bottom). Lateral (left/right) RADIAL: Oral (where openings are located) Aboral (opposite)

  8. Radial Continued Lack Cephalization: Aggregation of nerve cells in one region which would define a head. What are some other examples of organisms that display radial symmetry?

  9. Body Plans: Digestion Most animals have a body plan best described as a "tube-within-a-tube”or ONE WAY SYSTEM. This plan calls for two openings: one for food to enter the body (mouth), one for wastes to leave the body (anus). Animals with this plan are more efficient at digesting and absorbing their food than animals with the sac-like body plan. The one way system plan allows specialization of parts along the tube. The sac-like body plan has only one opening for both food intake and waste removal. Sac-like body plan animals do not have tissue specialization or development of organs

  10. Refresher of additional terms: Sessile: no movement: some aquatic animals. Passive feeders Motile: ability to move and search for food. Gametes: are sperm (male) and ova (female) Gametes are haploid (N) half the genetic material, they come together to form Zygotes which are diploid (2N) Asexual reproduction is rare in animals and only in lower forms.

  11. Vocab Continued Polymorphism: (many forms) possessing more than one distinct body form (like caterpillars and butterflies) during a life cycle. Often these alternating forms bear little resemblance to each other. Metamorphism: the process where an organism changes body structures. Many insects undergo this process. Broadcasters: simple aquatic animals shed gametes into the water like plants do with pollen. Based on timing and location. hermaphroditic: less motile animals, possess both male and female reproductive organs. Do not self fertilize, released at different times to ensure cross fertilization.

  12. Vid break Tadpole Trials: http://video.nationalgeographic.com/video/player/animals/amphibians-animals/frogs-and-toads/frog_greentree_lifecycle.html

  13. Phylum Porifera • Sponges: simplest animals. • Generally considered radially symmetrical or asymmetrical • Sessile • Hermaphroditic • Lacking cephalization • Doesn’t sound like much of an animal does it?

  14. General Info: Feeding Normally anchored in warm ocean water, survive by passing water through their body cavity. Porifera literally means ‘pore bearing’ or having pores. So they must play a role right? Pores are INCURRENT OPENINGS: passages ways for water, gases and nutrients to enter the internal cavity. Openings are formed by PORE CELLS called POROCYTES.

  15. structure

  16. continued Pore cells can regulate their size to control water flow. Kind of like stoma in a sense. Water exits the sponge through the EXCURRENTOPENING or OSCULUM. How does the water ‘flow?’ COLLAR CELLS: line internal cavity and create currents by the movement of flagella. Cells lining the cavity extract food and oxygen and dispose of cellular wastes

  17. General Info: Structure Internal skeleton is created by specialized cells called: AMOEBOCYTES. Secrete salts like calcium carbonate or silicon dioxide to form SPICULES. Softer ‘bath sponges’ produce SPONGEON FIBRES which are soft and flexible.

  18. Sponge Skeleton Caption: Natural sponge. Coloured scanning electron micrograph (SEM) showing the branching structure of the body of a natural sponge (phylum porifera). Sponges are primitive aquatic animals that filter food from the water. Their bodies are supported by an internal skeleton of calcium or silicon based spicules (spines), and fibres of the protein spongin. Magnification: x62 when printed 10 centimetres wide.

  19. Reproduction • Sponges have a lot of reproductive options: • They are hermaphrodites meaning the have both male and female reproductive organs. • Sperm are produced by Amoebocytes cells. • No self fertilization: BROADCASTERS. • Capable of REGENERATION: chop them off and they grow back. • Asexual Reproduction: GEMMULES spore like structures formed during poor conditions. Sent out with spent water.

  20. Gemmules Gemmules are internal buds found in sponges that are the result of asexualreproduction, and are a response to a hostile environment. They are resistant to desiccation (drying out), freezing, and anoxia (lack of oxygen) and can lie around for long periods of time. These are similar to a bacterium's endospore. Gemmules are made up of amoebocytes surrounded by a layer of spicules and can survive conditions that would kill adult sponges. When the environment becomes less hostile, the gemmule resumes growing.

  21. Final Thoughts Even though sponges are an animal, they lack true tissues. They do however have specialized cells. Cells function individually without intercellular communication. http://www.youtube.com/watch?v=RmPTM965-1c http://www.youtube.com/watch?v=BW05vMziy2o&feature=related

  22. Big Q’s What are the benefits and disadvantages of each type of reproduction for a sponge? Broadcasting (sexual), Sessile & hermaphroditic, Gemmules (asexual) and regeneration Would you classify a sponge as more of a plant or more of an animal. Why? Which seedless or seed plant does it remind you of? What connections do they share?

  23. Summary Table

  24. Cnidarians Radial Symmetry: Members includes Hydra Jellyfish Portuguese man-o-war Sea anemones All united by special cells called nematocysts.

  25. Nematocysts These are specialized stinging cells, and they’re really fast! When something in the environment (food) triggers the barb extending from the surface of the nematocyst, the cell collapses and shoots out a protein filament designed to harpoon its prey. Filaments has a chemical anesthetic which paralyses the food to be ingested. Nematocysts http://www.youtube.com/watch?v=-Tp38DUjUnM&feature=related

  26. Toxins Jellyfish toxins include a poorly understood array of complex chemicals.   Many have negative effects on cell membranes and cause them to rupture.  This may, for example, lead to the breaking up of red blood cells, certainly not a desirable response to a sting.  Other toxins have disruptive effects on the action of nerve and muscle cell membranes and impair their normal function.  Throw in toxins that degrade collagen, break down proteins and lipids, and disrupt cellular influx of ions like calcium, and you can see why jellyfish mean business.       So behold the amazing nematocyst.  Although small in stature, the combined efforts of multitudes of these microscopic workhorses is sufficient to subdue creatures that seemingly should have no problem against a delicate gelatinous blob.  Nematocysts are one more reason to admire our gelatinous friends, and they are key to the success that jellyfish and their cnidarian relatives have had in conquering all marine habitats.

  27. Video Break http://www.youtube.com/watch?v=AjM-WOeM3uA Jellyfish invasion http://www.youtube.com/watch?v=eyCigZ_bsTM&feature=related

  28. Sessile Body Forms All cnidarians have a sac-like body form Some are sessile (these are termed POLYPS) Generally have an elongated body ending in a mouth surrounded by feeding tentacles. Nematocysts are found on the tentacles.

  29. Motile Forms When a cnidarian is motile, it is termed a MEDUSA Very much like an inverted polyp. Has a bell shaped digestive cavity. Capable of changing the shape of its bell to propel itself through the water.

  30. Body Walls • Body walls of both forms are constructed out of two tissue layers held apart by a third gel-like layer called the MESOGLEA • It acts as the creatures' structural support in water, as they lack bones or cartilage, endo- or exoskeletons, or similar means of support. Because mesoglea is a gel with such a high water content, these creatures tend to collapse on land • ENDODERM: inner layer specialized to digest prey using enzymes. Surrounds the GASTROVASCULAR CAVITY which acts as the stomach. • ECTODERM: outer layer. Offers some protection from environment but also contains the nematocysts.

  31. More about the Mesoglea The most interesting layer…debatable. Random jumble of different cell types Some cells are nerve like since they conduct messages Form a NERVE NET since they do not from a centralized system. Other cells in the Mesoglea become reproductive cells. M&F, remember they’re hermaphrodites. These cells allow the Cnidarians to respond to their environment. (Ever poked an anemone?)

  32. Class: Hydrozoa

  33. Unity of Tissue, but not shapes • Cnidarians: Extremely diverse in body forms • We’ll Discuss Three Classes of Cnidarians: • Hydrozoans: Generally Sessile Polyps • They are broadcasters, and reproduce asexually by budding. • Portuguese Man-o-War are a well known example • http://www.youtube.com/watch?v=lem0RAVzVCM • Turtle food: http://www.youtube.com/watch?v=Iap6XiO-Wv0&feature=related

  34. Portuguese Man-of-War Although a member of the phylum Cnidaria, the Portuguese man-of-war is not a "true" jellyfish. These animals consist of a complex colony of individual members, including a float, modified feeding polyps and reproductive medusae. Physalia typically inhabit the warm waters of the tropics, subtropics and Gulf Stream. Propelled by wind and ocean currents, they sometimes drift into nearshore waters of South Carolina. Though they infrequently visit our coast, swimmers should learn to identify these highly venomous creatures. The gas-filled float of the man-of-war is purple-blue and can reach lengths of 10 inches. Under the float, tentacles equipped with thousands of nematocysts hang from the feeding polyps extending as much as 30 to 60 feet. The man-of-war can inflict extremely painful stings. Symptoms include severe shooting pain described as a shock-like sensation, and intense joint and muscle pain. Pain may be accompanied by headaches, shock, collapse, faintness, hysteria, chills, fever, nausea and vomiting.

  35. Class: Scyphozoa

  36. Schyphozoans • Motile with a a medusa body from for most of their lives. • Usually called Jellyfish. • Grouped together because of their POLYMORPHIC life cycles. • Adults are typically male or female. • Gametes are released into the water where fertilization occurs. • Resulting ZYGOTEdevelops into a larvae which attaches to a surface and becomes a polyp.

  37. Life Cycle of a Cnidarian

  38. Class: Anthozoa

  39. Class Anthozoa Primarily Sessile Polyps Have more complex tissues than Schyphozoans and Hydrozoans Both colonial and solitary examples Included anemones and coral forming species. Not Polymorphic. http://www.youtube.com/watch?v=zkVo-H7bfxs&feature=related

  40. Videos Killer Jelly http://www.youtube.com/watch?v=NbpB5F9CcLc&feature=related Box Jellyfish http://www.youtube.com/watch?v=b6GuAaW9f58 Jelly Fish Life cycle: http://www.youtube.com/watch?v=Id53jmsdxfQ&feature=related GELATO FISH! http://www.youtube.com/watch?v=ct9KyLmnu0I Reviewhttp://www.brsd.org/education/components/scrapbook/default.php?sectiondetailid=2348

More Related