Chapter 11 Structure and Function of Invertebrates 11.1 What is an Animal? 11.2 Sponges and Cnidarians 11.3 Worms and Mollusks 11.4 Arthropods 11.5 Echinoderms.

Chapter 11 Structure and Function of Invertebrates

11.1 What is an Animal?

11.2 Sponges and Cnidarians

11.3 Worms and Mollusks

11.4 Arthropods

11.5 Echinoderms

Table of ContentsChapter Preview

11.1 What is an Animal?

11.2 Sponges and Cnidarians

11.3 Worms and Mollusks

11.4 Arthropods

11.5 Echinoderms


Chapter Preview Questions

1. Which of the following animals appeared first during Earth’s history?

a. fishes

b. mammals

c. worms

d. reptiles



1. Which of the following animals appeared first during Earth’s history?

a. fishes

b. mammals

c. worms

d. reptiles



2. Which of the following structures is NOT found in animal cells?

a. cell wall

b. cell membrane

c. mitochondria

d. nucleus



2. Which of the following structures is NOT found in animal cells?

a. cell wall

b. cell membrane

c. mitochondria

d. nucleus



3. If an animal reproduces asexually, it

a. has two parent organisms.

b. undergoes conjugation.

c. is genetically identical to its offspring.

d. inherits two different sets of alleles.



3. If an animal reproduces asexually, it

a. has two parent organisms.

b. undergoes conjugation.

c. is genetically identical to its offspring.

d. inherits two different sets of alleles.



4. If an animal has specialized tissues and organs, the animal’s cells have undergone

a. photosynthesis.

b. osmosis.

c. selective breeding.

d. differentiation.



4. If an animal has specialized tissues and organs, the animal’s cells have undergone

a. photosynthesis.

b. osmosis.

c. selective breeding.

d. differentiation.


On a walk through the park, you stop to look closely at the leaves of a plant. You see an insect laying eggs. The eggs are the result of sexual reproduction. The cells in each insect egg contain many genes. Where do these genes come from? Explain your answer.

What major functions do animals’ bodies perform?


Use Clues to Determine Meaning

The animals called cnidarians have two differentbody plans. One form looks something like a vase.The vase-shaped body plan is called a polyp. A polypís mouth opens at the top and its tentaclesspread out from around the mouth.

What apolyp is

Additional informationabout a polyp


Apply It!

1. In your own words, what is the meaning of polyp?

Sample: A polyp is a vase-shaped cnidarian.

2. What sentence contains the definition of polyp?

Sentence 3

3. What other clues help you understand the meaning of polyp?

The last sentence tells me it has a mouth that opens at the top and is surrounded by spreading tentacles.


End of Chapter Preview


Section 1: What is an Animal?

How are animal bodies typically organized?What are the four major functions of animals?What is symmetry?How are animals classified?


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


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


Classification of Animals

This branching tree shows how the major animal groupsare related.


Links on the Animal Kingdom

Click the SciLinks button for links on the animal kingdom.


The Animal Kingdom

Click the Video button to watch a movie aboutthe animal kingdom.


End of Section: What Is an Animal?


Section 2: Sponges and Cnidarians?

What are the main characteristics of sponges?What are the main characteristics of cnidarians?


Sponges

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


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.


Cnidarians

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


Cnidarians

Cnidarians 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, and both sexual and asexual reproduction.


Invertebrates

Click the Video button to watch a movie about invertebrates.


End of Section: Sponges and

Cnidarians


Section 3: Worms and Mollusks

What are the main characteristics of worms?What are the main characteristics of each phylum of worms?What are the main characteristics of mollusks?What are eth main groups of mollusks?


Characteristics of Worms

Biologists classify worms into three major phyla—flatworms, roundworms, and segmented worms.


Life Cycle of a Dog Tapeworm

This tapeworm 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.


Roundworm Numbers

In the first centimeter

Reading Graphs:

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


Roundworm Numbers

About 87%

Calculating:

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


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?


Segmented Worms

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


Characteristics of Mollusks

Although they don’t look much alike at first, a snail, a clam, and a squid have the same basic body structures.


Snails and Slugs

Gastropods such as this land snail have an organ called a radula, which tears and scrapes up food.


More on Worms

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


End of Section: Worms and Mollusks


Section 4: Arthropods

What are the general characteristics of arthropods?What are the distinguishing structures of crustaceans, arachnids, centipedes and millipedes, and insects?


Characteristics of Arthropods

Members of the largest arthropod groups differ in several characteristics.


Crustaceans

A crustacean is an arthropod that has two or three body sections, five or more pairs of legs, and two pairs of antennae.


Body Structure

Insects are arthropods with three body sections, six legs, one pair of antennae, and usually one or two pairs of wings.


Life Cycle

An insect with complete metamorphosis has four different stages: egg, larva, pupa, and adult.


Life Cycle

An insect with gradual metamorphosis has no distinct larval stage. An egg hatches into a stage called a nymph, which usually looks like the adult insect without wings.


Links on Arthropods

Click the SciLinks button for links on arthropods.


Insect Adaptations

Click the Video button to watch a movie aboutinsect adaptations.


End of Section: Arthropods


Section 5: Echinoderms

What are the main characteristics of echinoderms?What are the major groups of echinoderms?


Characteristics of Echinoderms

Echinoderms, such as this sea star, have a water vascular system that helps them move and catch food.


Water Vascular System Activity

Click the Active Art button to open a browser window and access Active Art about the water vascular system.


Diversity of Echinoderms

There are four major groups of echinoderms: sea stars, brittle stars, sea urchins, and sea cucumbers. All have radial symmetry and are found in the ocean.


End of Section: Echinoderms


QuickTake Quiz

Click to start quiz.

Chapter 11 Structure and Function of Invertebrates 11.1 What is an Animal? 11.2 Sponges and Cnidarians 11.3 Worms and Mollusks 11.4 Arthropods 11.5 Echinoderms.

Documents

polyp slide

nucleus slide

animal cells

animals cells

following animals

meaning of polyp

definition of polyp

animals bodies