Download Sponges and Cnidarians

4/14/15
Mr.Faia
6th Grade Science
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For a long time, sponges were thought of as
plants
Sponges stay in 1 place, but are heterotrophs
They have been
around for 540 million years!
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Sponges have irregular shapes and no
symmetry
Some cells have specialized jobs
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The body of a sponge is like a bag pierced with
holes
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These holes are called pores
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Sponges strain food from water
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Collar cells trap food as water passes through
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Oxygen enters the sponge by diffusion
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What is diffusion?
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What else can diffusion do for a sponge?
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Sponge bodies are supported by spikes
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Spikes can be very sharp
Sponges can also produce irritating substances
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What do we call these traits?
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Can reproduce both sexually and asexually
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Budding –
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Produce egg cells during 1 point of year
Produce sperm cells during another point
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After fertilization, a larva forms
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3 Members of the phylum
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Jellyfish
Sea Anemones
Corals
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Traits
Stinging Cells
 Hollow cavity for food
 Carnivores
 Specialized Tissues
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Radial Symmetry
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2 Body plans
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Polyp
Medusa
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Polyp
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Hydra
Sea Anemone
Coral
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Medusa
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Jellyfish
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Cnidarians sting their prey with venom
Tentacles then pull the food into the mouth
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Where does undigested food go?
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Both asexually and sexually
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How does a polyp reproduce?
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Coral reefs start with a free-swimming coral
larva
Larva attaches to a solid surface
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Coral polyp reproduces asexually, and so does
its offspring
Over time the number of polyps can reach
thousands
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1) Describe the structure of a sponge’s body
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2) How do cnidarians capture food?
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3) How does a jellyfish capture food?
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4) How do polyps reproduce?
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5) What are the 2 types of cnidarian body plans?
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6) Which body type is free-swimming?
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7) What supports the body of a sponge?
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8) How do sponges get food?
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9) How does coral reproduce?
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10) What type of symmetry do sponges have?