Sponges, Cnidarians, and Worms

What Is an Animal?

Animal Symmetry

Sponges and Cnidarians

Worms

Table of Contents

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 AnimalsThis branching tree shows how the major animal groupsare 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

Comparing and ContrastingAs 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 Bilateral Symmetry

Many lines of symmetry, no distinct front end, live in water, move slowly

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

- Animal Symmetry

Sponges, Cnidarians, and Worms

Links on Animal Symmetry

Click the SciLinks button for links on animal symmetry.

- 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

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 and Cnidarians

Sponges, Cnidarians, and Worms

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/TimeFor example, a marble-sized sponge filters 15.6 liters of water in a day. How many liters does it filter per hour?

Practice ProblemIn four days, a sponge filters 1,200 L. What is its rate of water flow per day?

300 L/day

- Sponges and Cnidarians

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

Feature Sponges Cnidarians

Comparing and ContrastingAs you read, compare and contrast sponges and cnidarians by completing a table like the one below.

Body structure Hollow body with poresPolyp 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 and Cnidarians

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

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.

- Worms

Sponges, Cnidarians, and Worms

Roundworm Numbers

In the first centimeter

Reading Graphs:

Where in the soil was the largest percentage of roundworms found?

- Worms

Sponges, Cnidarians, and Worms

Roundworm Numbers

About 87%

Calculating:

What is the total percentage of roundworms found in the first 3-cm depth of soil?

- Worms

Sponges, Cnidarians, and Worms

Roundworm Numbers

The deeper the soil, the fewer the worms

Drawing Conclusions:

What is the relationship between the depth of soil and the abundance of roundworms in the soil?

- 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

Using Prior KnowledgeBefore you read, write what you know about worms in a graphic organizer like the one below. As you read, write what you learn.

1. Worms are long and skinny.2. Worms live in the ground and digest soil.3. Worms are slimy and wriggly.

1. Worms have bilateral symmetry.2. Some worms are flat.3. Some worms live in water.4. Some worms are parasites.5. Worms have a nervous system.

What You Know

What You Learned

- Worms

Sponges, Cnidarians, and Worms

More on Worms

Click the PHSchool.com button for an activity about worms.

- Worms

Sponges, Cnidarians, and Worms

End of Section:Worms

Sponges, Cnidarians, and Worms

Graphic Organizer

The Life of a Sponge

Sponge releases sperm.

Sperm enter another sponge and fertilize egg

cell.

Larva develops.Water currents carry away larva.

Larva settles on a surface and

develops into adult sponge.

Sponges, Cnidarians, and Worms

End of Section:Graphic Organizer