Sponges, Cnidarians, and Worms

What Is an Animal?

Animal Symmetry

Sponges and Cnidarians

Worms

Table of Contents


What is an Animal?

•Eukaryotic•Heterotrophic•Most are multi-cellular •Most are mobile•Most reproduce sexually


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?

http://dictionary.reference.com/browse/structure

http://dictionary.reference.com/browse/function

Sponges, Cnidarians, and Worms - What Is an Animal?

Structure of AnimalsThe cells of most animals are organized into higher levels of structure, including tissues, organs, and systems.

http://www.ncbi.nlm.nih.gov/About/primer/genetics_cell.html

http://en.wikipedia.org/wiki/Tissue_%28biology%29

http://www.bbc.co.uk/science/humanbody/body/factfiles/organs_anatomy.shtml

http://www.stcms.si.edu/hbs/hbs_student.htm


Function of AnimalsThe 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


How are animals classified?

•Body structure•Development•DNA*These criteria help classify animals into ~35 major groups or phylums.


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!


End of Section:What Is an Animal?


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


Links on Animal Symmetry

Click the SciLinks button for links on animal symmetry.

- Animal Symmetry

http://www.scilinks.org/fromoutside.asp?sciLINKSNumber=scn-0212&type=student


End of Section:Animal

Symmetry

Sponges, Cnidarians, and Worms - Sponges and Cnidarians

SpongesStructures surrounding the central cavity of a sponge are adapted for different functions.


SpongesThe sexual reproduction of sponges involves a larval stage that moves. Adult sponges stay in one place.


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


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



CnidariansCnidarians have two basic body plans, the vase-shaped polyp and the bowl-shaped medusa.


CnidariansCnidarians use stinging cells to capture food and defend themselves.


Cnidarians

The life cycle of a moon jelly has both a polyp and a medusa stage.


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 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



End of Section:Sponges and Cnidarians

Sponges, Cnidarians, and Worms - Worms

Characteristics of WormsBiologists classify worms into three major phyla—flatworms, roundworms, and segmented worms.


Life Cycle of a Dog TapewormThis flatworm is a parasite that lives in more that one host during its life cycle.


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


Roundworm Numbers

In the first centimeter

Reading Graphs:

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

- Worms


Roundworm Numbers

About 87%

Calculating:

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

- 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


Segmented WormsEarthworms and other segmented worms have bodies made up of many linked sections called segments.


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


More on Worms

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

- Worms

http://phschool.com/webcodes10/index.cfm?fuseaction=home.gotoWebCode&wcprefix=ced&wcsuffix=2014


End of Section: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.


End of Section:Graphic Organizer

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