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?
Structure of Animals
The cells of most animals are
organized into higher levels of
structure, including tissues,
organs, and systems.
Sponges, Cnidarians, and Worms
Functions of Animals
4 main functions:
1. Obtain food and oxygen:
Food: Herbivores---eat only plant material
Carnivores---eat only animal material
Omnivores---eat both plant and animal
material
Oxygen: take in oxygen in a variety of ways
ex: breathing, gills, air tubes, filter feeders, etc
2. Keep internal conditions stable:
HOMEOSTASIS Uses Adaptations
Ex: not too dry or wet, not too hot or cold
Sponges, Cnidarians, and Worms
3. Movement:
Ex: capture food; find shelter; find a mate;
escape predators
4. Reproduction:
Asexual: 1 parent
Example: Budding-a piece of the adult breaks
off and creates a new organism.
Sexual: 2 parents
Example: Sperm cell (male) unites with egg
cell (female)- fertilization occurs-creates a new
organism.
Sponges, Cnidarians, and Worms - What Is an Animal?
Classification of Animals
This branching tree shows how the major animal groups
are related.
Classified by:
1.
Body structure
2.
The way it develops
3.
DNA (genetic makeup)
Invertebrates: 97% of
all animals
Vertebrates: larger and
more complex
Sponges, Cnidarians, and Worms
Classification System
Largest: Kingdom
Phylum
Class
Order
Family
Genus
Smallest: Species
Sponges, Cnidarians, and Worms - What Is an Animal?
Asking Questions
Before you read, preview the red headings. In a graphic
organizer like the one below, ask a what or how question for
each heading. As you read, write answers to your questions.
Question
Answer
What is a cell?
A cell is the basic unit of structure and function in
living things.
What is the structure of
animals?
The cells of animals are organized into tissues,
organs, and systems.
What are the functions of
animals?
Animals must obtain food and oxygen, keep a
stable environment within their bodies, reproduce,
and move about to meet their needs.
How are animals classified?
Animals are classified according to how they
are related to other organisms.
Sponges, Cnidarians, and Worms - What Is an Animal?
Links on the Animal Kingdom
Click the SciLinks button for links on the animal kingdom.
Sponges, Cnidarians, and Worms - What Is an Animal?
The Animal Kingdom
Click the Video button to watch a movie about
the animal kingdom.
Sponges, Cnidarians, and Worms - What Is an Animal?
Invertebrates
Click the Video button to watch a movie about invertebrates.
Sponges, Cnidarians, and Worms
End of Section:
What Is an
Animal?
Sponges, Cnidarians, and Worms
Types of Symmetry
Bilateral Symmetry:
a single plane divides body into two mirror images
Sponges, Cnidarians, and Worms
Radial Symmetry:
can be cut in half along many planes that allow for
nearly identical halves
Sponges, Cnidarians, and Worms
Asymmetry
cannot be divided into mirror images
Sponges, Cnidarians, and Worms
What type of symmetry do each of the
following exhibit?
Sponges, Cnidarians, and Worms - Animal Symmetry
Comparing and Contrasting
Radial Symmetry
1. Many lines of
symmetry
2. no distinct front end
3. live in water
4. move slowly
Bilateral Symmetry
1.Balanced
1. One line of
arrangement of
symmetry
parts
2. halves that are
2. perform all the
mirror images
basic life
3. front end with sense
functions
organs
4. 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.
Larva: immature form of a sponge that looks very different
from the adult.
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
Segmented Worms
Earthworms and other segmented worms have bodies made
up of many linked sections called segments.
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
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
Body Structure
and Covering/
Specific
Adaptations
Food Getting/
Digestive
Process
Sponges
Cnidarians
Worms
Invertebrates
No Symmetry
No tissues or
organs
Spikes/pores/
colar cells/jellylike cells
Filter feeds—
collar cells trap
organisms, jellylike cells digest
food, waste
carries out
central cavity
Invertebrates
Stinging cells
Radial symmetry
2 body plans:
polyp and medusa
Can live in
colonies
Stinging cells
release
threadlike
structures that
paralyze prey.
Tentacles pull it
into the mouth.
Waste carried
out of mouth.
Invertebrates
Bilateral
symmetry
Long narrow
bodies
Flat, Round, &
Segmented
Flatworm-digest
outside and suck
it up. Waste exit
through feeding
tube.
Roundworms &
Segmented have
one way digestive
system
Sponges, Cnidarians, and Worms
Sponges
Cnidarians
Worms
Movement
Larva move but
settle on a
surface to
continue
development
Reproduction
Asexuallybudding
Sexually- no
separate sexes
Varied
Movement
Directed by a
nerve net
Used to escape
danger and get
food.
Asexualbudding
Sexual-some
are separate
male and
female, some
are not or do
both
Sense organs
sensitive to light,
touch, vibration.
Move using
muscles or
through their
host, some swim
Asexualregeneration
Sexual- some
separate male
and female,
some are not
Sponges, Cnidarians, and Worms
Respiratory
system
Sponges
Cnidarians
Worms
Oxygen moves
into cells as water
passes over them
Oxygen passes
across the body
surface directly
into cells
Take in oxygen
through their
skin. Skin must
be moist to
absorb water but
too much water
will block
oxygen.
Sponges, Cnidarians, and Worms
End of Section:
Graphic Organizer