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 11 Preview Questions

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

a. fishesb. mammalsc. wormsd. reptiles

Chapter 11 Preview Questions

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

a. fishesb. mammalsc. wormsd. reptiles

Chapter 11 Preview Questions

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

a. cell wallb. cell membranec. mitochondriad. nucleus

Chapter 11Preview Questions

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

a. cell wallb. cell membranec. mitochondriad. nucleus

Chapter 11 Preview Questions

3. If an animal reproduces asexually, ita. has two parent organisms.b. undergoes conjugation.c. is genetically identical to its

offspring.d. inherits two different sets of alleles.

Chapter 11 Preview Questions

3. If an animal reproduces asexually, ita. has two parent organisms.b. undergoes conjugation.c. is genetically identical to its

offspring.d. inherits two different sets of alleles.

Chapter 11 Preview Questions

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

a. photosynthesis.b. osmosis.c. selective breeding.d. differentiation.

Chapter 11 Preview Questions

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

a. photosynthesis.b. osmosis.c. selective breeding.d. differentiation.

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.

Section 11.1: 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 groups are related.

Section 11.2: 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.

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.

Section 11.3: Worms and

MollusksWhat 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 Mollusks

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

Phylum Molluska 

Characteristics of MollusksSoft bodies Most with a hard shellMantle to secrete shell and protect organs 3 Major Groups of Mollusks 1.Gastropods: snails and slugs

2.Bivalves: clams, oysters, scallops, and mussels

 3. Cephalopods: Octopuses, cuttlefish, squid, and nautiluses

Gastropods1. Gastropods: snails and slugsA single shell or no shell“Stomach foot”

Snails and Slugs

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

Bivalves2. Bivalves: clams, oysters, scallops, and musselsTwo shellsFilter feeders

CephalopodsCephalopods: Octopuses, cuttlefish, squid, and nautiluses

Swim by jet propulsion

Complex nervous system

Muscular tentacles with suckers

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.

Segmented Worms

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

Section 11.4: Arthropods

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

Arthropods Ch 11.4 

Characteristics of ArthropodsInvertebratesExoskeletonSegmented bodies“Jointed bodies”Open circulatory system  Major Groups of Arthropods 1. Crustaceans 2. Arachnids:  3. Centipedes and millipedes

Crustaceans  

1. Crustaceans: crabs, barnacles, shrimp, crayfish

Two or three body sections

3 pair of appendages for chewing5 or more pair of legs

Crustaceans

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

Arachnids2. Arachnids: spiders, ticks, mites,

and scorpions

Two body sections

8 pair of legs

no antennae

Insects

Phylum Arthropoda Characteristics of InsectsInvertebratesExoskeletonThree body sections (head, thorax, abdomen)One or two pair of wingsOpen circulatory systemSix legs CommunicationSoundPheromones (perfume for insects)

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 CycleAn 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.

Defense in Insects

FlyingCamouflageExoskeletonSmell or tasteStingers

Centipedes and millipedes

Segmented bodiesAppendages on each segmentCentipedes are carnivores

Section 11.5: Echinoderms

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

Phylum Echinodermata

  Characteristics of EchinodermsRadial symmetryOcean dwellers“spiney skinned”Endoskeleton of calcium platesWater vascular systemTube feet  

Characteristics of Echinoderms

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

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.