7th Grade Ch. 1 Sec. 3 Sponges & Cnidarians


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7th Grade Ch. 1 Sec. 3 Sponges & Cnidarians

  1. 1. Ch. 1 Sec. 3 Sponges & Cnidarians
  2. 2. Activity-How do natural and synthetic sponges compare? One similarity between a natural sponge and a synthetic sponge is ______________________________. One difference between a natural sponge and a synthetic sponge is ______________________________.
  3. 3. <ul><li>Are you ready Kids?  Aye, Aye Captain!  I can't hear you?  Aye, Aye Captain! </li></ul><ul><li>Ohhhhhh...Who lives in a pineapple under the sea? Spongebob Squarepants! Absorbent and yellow and porous is he!  </li></ul><ul><li>Spongebob Squarepants!  If nautical nonsense be something you wish? </li></ul><ul><li>Spongebob Squarepants!  Then drop on the deck and flop like a fish!  Spongebob Squarepants!  </li></ul><ul><li>Ready? Spongebob Squarepants, Spongebob Squarepants, Spongebob Squarepants, </li></ul><ul><li>S p o n g e b o b  S q u a r e p a n t s !   </li></ul>
  4. 5. sponges Sponges: Porifera [00:49] <ul><li>no symmetry </li></ul><ul><li>no organs </li></ul><ul><li>covered w/ pores </li></ul><ul><li>(small openings) </li></ul><ul><li>phylum- Porifera </li></ul><ul><li>(means having pores) </li></ul><ul><li>don’t move on own </li></ul><ul><li>protected by spikes </li></ul>
  5. 6. <ul><li>water moves  pores- carrying plankton & mainly one-celled organisms, which sponge traps & eats  collar cells trap food </li></ul><ul><li>diffusion: </li></ul><ul><ul><li>moves oxygen from water  sponge </li></ul></ul><ul><ul><li>carries waste from sponge  water </li></ul></ul>How Sponges Get Food & Oxygen from Water Sponges [01:00]
  6. 7. sponge reproduction sexual asexual <ul><li>sperm & eggs </li></ul><ul><li>produced by same sponge </li></ul><ul><li>exchanged with </li></ul><ul><li>separate sponge </li></ul><ul><li>budding = </li></ul><ul><li>small pieces break </li></ul><ul><li>off & form new sponges </li></ul>after fertilization- larva develop
  7. 8. <ul><li>The sexual reproduction of sponges involves a larval stage that moves. Adult sponges stay in one place. </li></ul>
  8. 9. A Closer Look at Sponges
  9. 10. Soak It Up activity-pg. 18 I predict that the ______ sponge will hold the most water. Answer Analyze & Conclude questions #1-2 pg. 18 Type of Sponge Mass of damp sponge (in grams) Size of pores Total volume Volume per gram Cellulose (bright yellow) Natural Foam (orange)
  10. 11. <ul><li>use &quot;stinging&quot; cells to capture prey & defense </li></ul><ul><li>take food into hollow, central cavity </li></ul><ul><li>have radial symmetry </li></ul>
  11. 12. While watching the video, note the following facts about cnidarians: body plans, life cycle, weapons & movement. Cnidarians: Polyps and Medusa [05:20]
  12. 13. Cnidarians capture their prey by using their stinging cells to inject venom to paralyze their prey.
  13. 14. Cnidarians have two basic body plans, the vase-shaped polyp and the bowl-shaped medusa.
  14. 15. jellyfish
  15. 16. Most polyps are adapted for a life attached to an underwater surface.
  16. 17. 2 body plans of cnidarians polyp medusa <ul><li>vase-shaped </li></ul><ul><li>mouth at top </li></ul><ul><li>do not move </li></ul><ul><li>bowl-shaped </li></ul><ul><li>mouth opens down </li></ul><ul><li>free-swimming </li></ul>hydra jellyfish
  17. 18. hydra- polyp
  18. 19. <ul><li>The life cycle of a moon jelly has both a polyp and a medusa stage. </li></ul>
  19. 20. cnidarian reproduction <ul><li>reproduce both sexually & asexually </li></ul>hydra budding
  20. 21. <ul><li>built by skeletons of cnidarians </li></ul><ul><li>coral polyps release eggs & sperm into water </li></ul><ul><li>when egg & sperm meet  larva </li></ul>Coral Reef
  21. 23. <ul><li>The baby coral looks like a little tiny jellyfish. </li></ul><ul><li>It floats around in the water until it finds a hard place to attach to, usually a coral reef. </li></ul>coral polyp
  22. 24. <ul><li>A coral reef is about a million of these individual coral polyp shells all stuck one on top of the other. </li></ul><ul><li>When coral polyps die, new ones land and grow right on top of the old empty shells. </li></ul><ul><li>There are over 500 different species of coral. Some look like brains and some like fans and some like the antlers of deer, but they are all made up of tiny coral polyps. </li></ul>
  23. 25. <ul><li>Organisms other than coral can form reefs. </li></ul><ul><li>A reef is simply a structure in the shallow parts of the ocean that serves as a home to animals and plants. </li></ul><ul><li>Many sunken ships have become reefs and humans even create artificial reefs to replace the coral reefs that we have destroyed. </li></ul><ul><li>Some artificial reefs are specially constructed for the purpose, but others are made of tires linked together, old appliances linked together and even discarded military equipment like tanks and helicopters. </li></ul>
  24. 26. Artificial Reefs decommissioned aircraft sunken subway cars reef balls which include the cremated remains of a loved one
  25. 27. Feature Sponges Cnidarians Comparing and Contrasting Sponges & Cnidarians Body structure Cell type that traps food Method(s) of reproduction Hollow body w/ pores Collar cells Sexual & asexual Polyp or medusa, central body cavity, tentacles Stinging cells Sexual & asexual