Transcript Sponges and Cnidarians

Write down all of the letters in the Alphabet
(use uppercase).
 Circle the letters that have radial symmetry
in red.
 Circle the letters that have bilateral
symmetry in blue.
 Circle the letters that are asymmetrical in
yellow.
 *Some letters may have more than 1 type
of symmetry!*

Students will…
 Describe the structures that make up
sponges and cnidarians.
 Compare how sponges and cnidarians
get food and reproduce.
 Review Self Check Homework

 Characteristics
of Sponges
A. Filter Feeders
 - Sponges filter food from the water
that flows through their bodies.
 -Do not make own food!
B. Body Support and Defenses
 - spicules and spongin protect sponges
from predators
 What are spicules and spongin?
C. Sponge Reproduction
 - sponges can reproduces sexually
and asexually
 There are not male/female sponges!
 See chart on pg. 502 for more details.
D. Sponges are Sessile
 -Adult sponges do not move from
place to place.
Characteristics of Cnidarians
 Include Jellyfish, Sea Anemones, Hydra
and Coral
 Have radial symmetry
 Are hollow bodied animals with 2 cell
layers that are organized into tissues.
 Have tentacles around their mouth to
help catch food
2 different body forms
 Polyp-vase shaped body (sea
anemone or hydra)
 Medusa-free swimming bell
shaped (jelly fish)
 Some cnidarians go through both
stages during their life cycle
Main Stages of Reproduction
 1. Larva attaches to a surface
 2. Polyp grows
 3. Young medusa buds off (asexual
reproduction)
 4. Sexual reproduction-male medusa
releases sperm and female releases
eggs
 5. New larve are produced

http://www.ck12.org/user:kay.teehan@p
olk-fl.net/section/Sponges-andCnidarians/

Name one difference between sponges
and cnidarians.
For Next Time….
 Read pgs. 504-505
 Define polyp and medusa on index
cards


How do sponges and cnidarians get their
food?
Sponges-filter food out of the water as it
comes to them
 Cnidarians-actively capture prey with
their tentacles that have stinging cells.

Students will
 Differentiate between flatworms and
roundworms through the creation of a
foldable


Create foldable according to teacher
instructions
Characteristics
Body Shape
Body Openings
Body Construction
Digestive System
Picture
Flatworms
Roundworms
Characteristics
Flatworms
Roundworms
Body Shape
Long and Flat
Long and round
Body Openings
One
Two
Body Construction
Three Layers
Fluid-filled cavity
between 2 tubes
Digestive System
Most do not have
their own digestive
system
Have a digestive
system
Picture
Type of parasitic flatworm
 To survive, it lives in the intestines of its
host (including humans!)
 Since it does not have a digestive system,
it absorbs nutrients from digested
material in the host’s intestine.
 How do tapeworms get into humans?
 Tapeworm length activity

Why parasites might not be all that bad
 Flatworms
 Roundworms

 Read
pgs. 506-508
 Define organ, mollusks, mantle,
gills and radula on index cards.
 Due on Friday, 11/1.