Sponges, Cnidarians, and Worms
Table of Contents
What Is an Animal?
Animal Symmetry
Sponges and Cnidarians
Worms
Sponges, Cnidarians, and Worms
What is an Animal?
•Eukaryotic
•Heterotrophic
•Most are multi-cellular
•Most are mobile
•Most reproduce sexually
Sponges, Cnidarians, and Worms
Structure vs. Function
•What is the difference?
•http://dictionary.reference.com/browse/structure
•http://dictionary.reference.com/browse/function
•How do these terms relate to Biology and the study of animals?
Sponges, Cnidarians, and Worms - What Is an Animal?
Structure of Animals
The cells of most animals are
organized into higher levels of
structure, including tissues,
organs, and systems.
Sponges, Cnidarians, and Worms
Function of Animals
The four major functions of all animals include:
I.
Obtaining Food & Oxygen
II.
Keeping Conditions Stable
III. Movement
IV. Reproduction
Animals have adaptations that allow them to perform these
basic functions in their respective environments.
Sponges, Cnidarians, and Worms - What Is an Animal?
Classification of Animals
This branching tree shows how the major animal groups
are related. There
Sponges, Cnidarians, and Worms
How are animals classified?
•Body structure
•Development
•DNA
*These criteria help classify animals
into ~35 major groups or phylums.
Sponges, Cnidarians, and Worms
Vertebrates vs. Invertebrates
•Vertebrates are simply animals with a backbone (like
yourself)
•Invertebrates are animals without a backbone
*The majority of all animals are invertebrates!
Sponges, Cnidarians, and Worms
End of Section:
What Is an
Animal?
Sponges, Cnidarians, and Worms - Animal Symmetry
Comparing and Contrasting
As you read, compare and contrast the characteristics of
animals with bilateral symmetry and radial symmetry in a
Venn diagram like the one below. Write the similarities in the
space where the circles overlap and the differences on the
left and right sides.
Radial Symmetry
Many lines of
symmetry, no
distinct front end,
live in water, move
slowly
Bilateral Symmetry
Balanced
arrangement of
parts, perform all
the basic life
functions
One line of
symmetry, halves
that are mirror
images, front end
with sense organs,
quick movement
Sponges, Cnidarians, and Worms - Animal Symmetry
Links on Animal Symmetry
Click the SciLinks button for links on animal symmetry.
Sponges, Cnidarians, and Worms
End of Section:
Animal
Symmetry
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Sponges
Structures surrounding the central cavity of a sponge are
adapted for different functions.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Sponges
The sexual reproduction of sponges involves a larval stage
that moves. Adult sponges stay in one place.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Structure of a Sponge Activity
Click the Active Art button to open a browser window and
access Active Art about the structure of a sponge.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Calculating a Rate
To calculate the rate of water flow in a sponge, divide the
volume of water that the sponge filters by the time it takes
the water to pass through the sponge.
Flow rate = Volume of water/Time
For example, a marble-sized sponge filters 15.6 liters of water in a
day. How many liters does it filter per hour?
Practice Problem
In four days, a sponge filters 1,200 L. What is its rate of water flow
per day?
300 L/day
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Cnidarians
Cnidarians have two basic body plans, the vase-shaped
polyp and the bowl-shaped medusa.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Cnidarians
Cnidarians use stinging cells to capture food and defend
themselves.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Cnidarians
The life cycle of a
moon jelly has both
a polyp and a
medusa stage.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Comparing and Contrasting
As you read, compare and contrast sponges and cnidarians
by completing a table like the one below.
Feature
Sponges
Cnidarians
Body structure
Hollow body with pores
Polyp or medusa, central
body cavity, tentacles
Cell type that traps food
Collar cells
Stinging cells
Method(s) of
reproduction
Sexual and asexual
Sexual and asexual
Sponges, Cnidarians, and Worms
End of Section:
Sponges and
Cnidarians
Sponges, Cnidarians, and Worms - Worms
Characteristics of Worms
Biologists classify worms into three major phyla—flatworms,
roundworms, and segmented worms.
Sponges, Cnidarians, and Worms - Worms
Life Cycle of a Dog Tapeworm
This flatworm is a parasite that lives in more that one host
during its life cycle.
Sponges, Cnidarians, and Worms - Worms
Roundworm Numbers
Biologists counted all the
roundworms living in a plot of
soil. Then they calculated the
percentage that lives in different
depths of soil.
Sponges, Cnidarians, and Worms - Worms
Roundworm Numbers
Reading Graphs:
Where in the soil was the
largest percentage of
roundworms found?
In the first centimeter
Sponges, Cnidarians, and Worms - Worms
Roundworm Numbers
Calculating:
What is the total percentage
of roundworms found in the
first 3-cm depth of soil?
About 87%
Sponges, Cnidarians, and Worms - Worms
Roundworm Numbers
Drawing Conclusions:
What is the relationship
between the depth of soil and
the abundance of
roundworms in the soil?
The deeper the soil, the fewer
the worms
Sponges, Cnidarians, and Worms - Worms
Segmented Worms
Earthworms and other segmented worms have bodies made
up of many linked sections called segments.
Sponges, Cnidarians, and Worms - Worms
Using Prior Knowledge
Before you read, write what you know about worms in a
graphic organizer like the one below. As you read, write what
you learn.
What You Know
1. Worms are long and skinny.
2. Worms live in the ground and digest soil.
3. Worms are slimy and wriggly.
What You Learned
1.
2.
3.
4.
5.
Worms have bilateral symmetry.
Some worms are flat.
Some worms live in water.
Some worms are parasites.
Worms have a nervous system.
Sponges, Cnidarians, and Worms - Worms
More on Worms
Click the PHSchool.com button for an activity about worms.
Sponges, Cnidarians, and Worms
End of Section:
Worms
Sponges, Cnidarians, and Worms
Graphic Organizer
Sponge releases
sperm.
Larva settles on a
surface and
develops into adult
sponge.
The Life of a
Sponge
Water currents
carry away larva.
Sperm enter
another sponge
and fertilize egg
cell.
Larva develops.
Sponges, Cnidarians, and Worms
End of Section:
Graphic Organizer