Cnidaria, Porifera, and Birds

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Cnidaria, Porifera, and Birds

• By Megan and Jami

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Porifera

• Porifera, otherwise known as sponges, are
  animals.
• They live mostly in the water, and do not move.
• They are filter feeders, and collect food from
  water passing through.
• Sponges have radial symmetry, meaning that the
  body is arranged around a central axis.

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Picture of a Porifera
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Specialization of Porifera

• Choanocytes are the inner layer of cells that
  help water move through the body
• Amoebocytes produce skeletal fibers so that the
  sponge has structure and shape.
• Skeletal fibers of a sponge have minerals or
  protein called spongin.

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Digestion

• Sponges are filter feeders, they filter water
  through their bodies and trap food with their
  digestive system.
• Sponges must filter about 275 gallons of seawater
  to grow only 3 ounces.
• The choanocytes trap bacteria and then the
  ameobocytes digest it and carry nutrients to
  other cells.

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Reproduction, Interesting facts

• They reproduce sexually
• They are the simplest animal, with no nerves or
  muscles.
• Individual cells and layers of cells can change
  and react with the environment
• They dont really have tissue, the cells arent
  specialized.
• The sponge evolved from organisms in the
  Precambrian era, and arose from the first
  multicellular organisms.

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Cnidaria

• Cnidarians are jellyfish, hydras, sea anemones,
  and corals.
• All have radial symmetry, one of the traits of
  this phylum.
• They have stingers, called cnidocytes on the
  ends of their tentacles.

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Picture
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Specializations

• They have two kinds of body types
• Polyps have cylindrical bodies with tentacles
  from one end
• Medusas have many tentacles and a dome shaped
  body type

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Digestion, Reproduction

• Digestion is said to be incomplete because they
  have no anus food is taken in through the mouth,
  digested in the gastrovascular cavity, and extra
  food comes back out the mouth.
• They are considered carnivores, their tentacles
  capture the food with the cnidocytes, which sting
  or stun their prey.
• They reproduce sexually

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Birds
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Birds

• Class Aves there are about 8,600 species of
  birds.
• Surprisingly, they are closely related to
  reptiles there are fossils linking birds to two
  legged dinosaurs. Like reptiles, birds have
  amniotic eggs, scales on their legs, toenails,
  and body form.
• Overall, modern birds have evolved from a small
  group of dinosaurs.

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Flight

• The bird has been adapted in order to fly.
• Reduced weight is caused by a lack of teeth, few
  vertebrae in the tail, hollow shafts in the
  feathers, and strong but light bones due to their
  honeycombed structure.
• In addition, they have wings, large breast
  muscles, fast metabolism for energy, etc
• There are a number of flightless birds, for
  example the ostrich and emu.

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The Digestive System
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Reproduction

• Through a complicated courtship ritual, males and
  females mate, usually only dominant males getting
  a partner.
• Birds sexually reproduce, creating eggs that
  hatch the babies.

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Bibliography

• http//library.thinkquest.org/26153/marine/sketch/
  586a.jpg
• http//www.okc.cc.ok.us/biologylabs/Images/Animal_
  Images/cnidarian_body.gif
• http//ftp.pcworld.com/pub/screencams/the-birds.jp
  g
• http//www.nhm.org/birds/guide/005a.jpg
• http//mk29.image.pbase.com/v3/09/552609/1/4529318
  8.eggs.jpg
• Biology textbook.