Topic 21: Porifera and Cnidaria Flashcards

• what is the phylum Porifera informally known as


  sponges
• what phylum are basal animals that lack true tissues


  porifera
• what range of height can Porifera get

  a few mm to a few meters in height.
• sponges are sessile except for what stage?

  larval
• what do sponges lack?

  true tissues
• what 4 things do sponges not have if they lack true tissue?

  • internal organs
  • muscles
  • nervous system
  • circulatory system.
• what in sponges have a specialized function?

  Some cells
• Structural support comes from what in sponges

  spicules
• what are spicules?

  Tiny, hard needles or rods that support the sponges structure
• what are spicules made of

  silica or calcium carbonate
• what do some sponges have if they don't have spicules?

  spongin
• what is spongin?

  fibrous collagen - protein network for support in sponges
• what four cells compose a sponge?

  • porocytes
  • Epidermal cells
  • Choanocytes
  • amoebocytes
• what do choanocytes line in the sponge?

  line the spongocoel
• What is the spongocoel in a sponge?

  it is the large, central cavity of sponges
• what flows into the spongocoel in sponges?

  water
• what is the function of Choanocytes in sponges (4 total)?

  what does it do? (2) what does it bring in? (1)- what does it remove? (1)

  • generate a water current that goes through the sponge
  • ingests suspended food
  • brings in oxygen and nutrients to the sponge
  • removes waste and CO2
• what are Choanocytes also known as?

  collar cells
• Where are amoebocytes found in a sponge?

  in the mesohyl
• What is the mesohyl in a sponge?

  gelatinous extracellular matrix
• what does the mesohyl act as?

  acts as an endoskeleton
• what maintains the tubular morphology in sponges?

  the gelatinous mesohyl
• what is the function of mobile amoebocytes in sponges? (3)

  • transport nutrients to other cells of the sponge body
  • produce materials for skeletal fibres (spicules)
  • can become any type of sponge cell as needed
• what are porocytes in sponges?

  tubular cells that make up the pores of a sponge
• what are epidermal cells in sponges?

  they're tightly packed cells that make up the outer layer of the spongie body
• the body of a sponge consists of what two layers

  • epidermis layer
  • choanocyte layer
• what are the two layers that make up the body of a sponge separated by?

  mesohyl-"middle matter"
• What does the mesohyl contain?

  • mobile amebocytes
  • skeletal elements (spicules or spongin) deposited by the amebocytes.
• what do the mobile amebocytes deposit in the mesohyl?

  skeletal elements:-either spicules or spongin
• Out of all the cells that compose a sponge, which one is mobile?

  amoebocytes
• What kind of feeders are sponges?

  suspension feeders
• what is suspension feeding?

  capturing food particles suspended in water passing through their body
• How is water drawn into the sponge?

  by beating of choanocyte flagella through pores
• what are the pores that water flow through in sponges called?

  ostia
• In sponges, what does the water flow into?

  a cavity called spongocoel
• In sponges, what does the water flow out of?

  an opening called the osculum
• what can collar cells in sponges extract?

  tiny particles (e.g. protist plankton)
• In collar cells, what traps the food particles?

  mucus-covered microvilli
• how are food particles digested in collar cells? (2)

  • engulfed by phagocytosis
  • digested or transferred to amoebocytes
• what do amoebocytes do with food/ nutrients? (2)

  • carry food/nutrients to other cells
  • use it to make structural materials (e.g. spicules)