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Porifera and Cnidarians

Porifera and Cnidarians. Porifera. Sponges are the simplest found in this phylum There are about 10,000 species of sponges and they are all aquatic Asymmetrical and only have specialized cells. Sponges. Digestion and Feeding. Filter feeders Sift plankton through collar cells

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Porifera and Cnidarians

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  1. Porifera and Cnidarians

  2. Porifera • Sponges are the simplest found in this phylum • There are about 10,000 species of sponges and they are all aquatic • Asymmetrical and only have specialized cells

  3. Sponges

  4. Digestion and Feeding • Filter feeders • Sift plankton through collar cells • Food is digested in a central cavity • Clean up ocean floor • Amebocytes, which are crawling cells, also help in feeding by distributing nutrients throughout the sponge.

  5. Respiration • All sponges perform respiration through their cell walls

  6. Circulatory • Sponges handle transportation by moving things through their body wall. • Amebocytes (crawling cells) also distribute nutrients throughout the Porifera’s body

  7. Excretion • Through an osculum(a large opening) • Amebocytes also transport CO2 and waste products through the osculum

  8. Response • They release protective chemicals, like toxins, to discourage predators

  9. Movement • Contain no nerves or muscles • They are sessile (meaning that they are attached to the floor) • Swimming larva are carried by currents before settling down and forming a new sponge. • Skeleton composed of spongin (soft) and spicules (hard)

  10. Reproduction • Reproduce sexually (sperm and eggs) • Most sponges are hermaphrodites, and self fertilization is AVOIDED by producing sperm and egg cells at different times. • Reproduce asexually (regeneration) • budding

  11. Cnidarians • jellyfish, coral, hydra, sea anemone • Named after the stinging cells found on their tentacles called CNIDOCYTES • Radial symmetry • Have two body forms: • Polyp (vase shaped) • Medusa (bowl shaped)

  12. Jellyfish Sea Anome Coral Hydra

  13. Feeding and Digestion • Most are carnivorous. • They have stinging tentacles called nematocysts. • Digestion takes place in their gastrovascularcavity.

  14. Respiration • Passes nutrients through cells by diffusion

  15. Circulatory • Their “skin” contains three layers; the epidermis, the mesoglea and the gastroderm. • They also have two germ layers

  16. Excretion • Through their mouth • Done by diffusion

  17. Response • Nervous system is build up of nerve nets • Corals produce poisons to protect themselves. • These poisons are used in cancer research and poison research.

  18. Movement • Non-swimming larva and swimming medusa • Hydrostatic skeleton that allows the them to change shape

  19. Reproduction • Sexual (medusa stage) • Release sperm, zygote develops on the females. • Hermaphrodites: they can fertilize themselves because they contain both male and female reproductive organs • Asexual (polyp stage) • Budding

  20. Flatworms • Members of the phylum Platyhelminthes • First phylum to have three germ layers: • Ectoderm • Mesoderm • Endoderm • Simplest animal with bilateral symmetry • Three classes of flatworms

  21. Feeding • Most are parasitic • Free-living : carnivores or scavengers; they have a digestive cavity, mouth and pharynx. Food is ingested through a muscular tube called the pharynx • Tapeworms have a hook and sucker that enables it to attach a host

  22. Respiration and Circulation • Diffusion through the body wall • Thin bodies allow for materials to diffuse (respiration, excretion, etc) • Flame Cell – specialized cells that remove excess water

  23. Response • Ganglia – group of nerve cells that control the body (like a brain) • Eyespot – group of cells that can detect light (like an eye)

  24. Movement Flatworms move in 2 way: • Cilia helps them glide through the water • Muscle cells help them twist and turn

  25. Reproduction • Sexual Reproduction – most flatworms are hermaphrodites (have both male and female sex organs) • Asexual Reproduction by fission  • flatworms can split in two and regenerate • Zygotes are passed out through the feces.

  26. Roundworms • Members of the phylum Nematoda • Unsegmented worms • Pseudocoelom (false coelom)

  27. Feeding and DIgestion • Can be: • Free-living – predators • Parasites - humans and animals • Digestive tract with 2 openings: mouth & anus

  28. Respiration and Circulation

  29. Excretion • Nitrogenous waste is excreted in the form of ammonia through the body wall

  30. Response

  31. MOvement

  32. Reproduction • Sexual reproduction, Separate sexes 

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