7ch11 - bement.k12.il.us

7ch11

Animal DiversityKingdom Animalia

Animal Characteristics

1. animals are eukaryotes and are multicellular2. cells are specialized for different functions

(vision,digestion,reproduction)3. protein, collagen surrounds the cells and keeps their

shape4. obtain energy for life processes by eating other organisms5. animals digest their food6. most animals reproduce sexually7. capable of movement at some point in their lives

Animal Classification

1.5 million species of animals with more added every year

How are animals grouped and classified?

Vertebrates - an animal with a backbone

Examples: fish, humans, birds, snake

Invertebrate - an animal that does not have a backbone

Examples: worms, spiders, insects, snails

Symmetry

Another way to classify animals -

Symmetry - an organism’s body plan

Radial symmetry - can be divided into two parts that are nearly

mirror images of each other anywhere

through its central axis.

Radial symmetry

A radial animal has a top and a bottom but no head or tail

It can be divided along more than one plane and still have identical halves

Examples: jellyfish, sea stars, sea anemones

Bilateral Symmetry

Bilateral symmetry - can be divided into two parts that are

nearly mirror images of each other.

Examples: birds, mammals, reptiles, worms, insects

Asymmetry

Asymmetry - cannot be divided into any two parts that are

nearly mirror images of each other

Examples: sponge

Molecular Classification

DNA, RNA and proteins in the cells can be used for classification

The more similar the DNA, the more closely related.

Phyla

Animals are classified into 35 phyla, 9 phyla contain 95%

Animals in the same phylum have similar body structures and characteristics

Figure 5 page 379

Lesson 2 Invertebrate Phyla

no backbone

no internal support

smaller than vertebrates

often move slower than vertebrates

95% of all animal species discovered are invertebrates

Sponges - Phylum Porifera

simplest of the invertebrates

● all sponges are asymmetrical● have no tissues, organs, or organ systems● cells are specialized for capturing food, digestion,

reproduction, and providing support● all sponges live in water, most in ocean environments● larval stage swims

Cnidarians - jellyfish, sea anemones, hydras, corals

● no organs or organ systems● radial symmetry● single body opening, surrounded by tentacles● simple tissues- muscles, nerves, digestive tissues● specialized cells, nematocysts (stinging cells) for defense

and capturing food● all live in water, most in ocean environments

Flatworms - phylum Platyhelminthes

● Bilateral symmetry● Nerve, muscle, and digestive tissues, simple brain● Soft, flat bodies a few cells thick● Digestive system has one opening● Live in moist environments● Parasites or free-living

Roundworms - phylum Nematoda

● Called nematodes● Bilateral symmetry● Nerve, muscle, and digestive tissues and simple brain● Bodies round, with stiff outer covering called a cuticle● Digestive system has 2 openings● Live in moist environments● Parasites or free - living

Phylum Mollusca

Snails, slugs, clams, mussels, octopi, and squid

● Bilateral symmetry● Soft bodies, some with hard shells● Digestive system with 2 openings● Body cavity contains heart, stomach, other organs● Blood but no blood vessels● Nervous system includes eyes, simple brains● Must live in wet environments

Phylum Mollusca

3 Groups

Snails and slugs

Clams and mussels

Octopi and squid

https://www.youtube.com/watch?v=SesRrocIFtc

Phylum Annelida earthworms, leeches, marine worms● Bilateral symmetry● Soft bodies● Body segments covered with a thin cuticle● Digestive system has 2 openings● Blood and blood vessels● Simple brain● Live in water or moist environments

Phylum Arthropoda

Insects, spiders, shrimp, crabs, lobsters

More species belong to this phylum than all other animal phyla

More than 1 million identified species

Phylum Arthropoda - Arthropods

● bilateral symmetry● exoskeleton● jointed appendages● body parts are segmented and specialized for different

functions● live in almost every environment on Earth

Appendage is a structure, such as a leg, that extends from the central part of the body

Largest Order of Arthropods -- Insects

Insects: Three pairs of jointed legs

Three body segments

A pair of antennae

16 major groups of insects, most belong to one of five groups

Beetles form the largest group - 40% of all known insect species

Phylum Arthropoda -- Order Arachnids

Spiders, ticks, and scorpions

All arachnids have: four pairs of jointed legs

two body segments

no antennae or wings

Phylum Arthropoda - Crustaceans

Crabs, shrimp, lobsters

All crustaceans have : one or two pairs of antennae

jointed appendages that are specialized

for biting and crushing food

Phylum Echinodermata

Echinoderms - “spiny skin”

Sea stars, sea cucumbers, sea urchins, sand dollars

Echinoderms have some unique features that are not in

any of the other invertebrate phyla.

Echinoderms

Radial symmetry

Hard plates inside skin support the body

Small, muscular tubes enable them to move (tube feet)

Complete digestive system

Live only in oceans

Lesson 3 Phylum Chordata

A chordate is an animal that has

● a notochord, ● a nerve cord, ● a tail, ● And pharyngeal pouches at some point in its life.

A notochord is a flexible, rod-shaped structure that supports the body of a developing chordate.

The nerve cord develops into the central nervous system.

The pharyngeal pouches are between the mouth and the digestive system.

Most chordates are vertebrates, but the chordates also include two groups of invertebrates: tunicates and lancelets

Tunicates and lancelets are only a few centimeters long and live in salt water - figure 16 p. 393

In vertebrate chordates, the notochord develops into a backbone during the growth of an embryo

Phylum Chordata

Lancelets

Tunicates

Vertebrates

A chordate is an animal that has

● a notochord, ● a nerve cord, ● a tail, ● And pharyngeal pouches at some point in its life.

Characteristics of Vertebrates

Backbone - series of structures that surround and protect the nerve cord (spinal cord)

Bones that form a backbone are called vertebrae

The nerve cord connects all the nerves in the body to the brain

Characteristics of Vertebrates

Backbone

Organ systems - digestive system with 2 openings

circulatory system - moves blood

nervous system - includes brain

5 Major Groups of Vertebrates

Fish

Amphibians

Reptiles

Birds

Mammals

Fish

● Spend entire life in water● Gills for absorbing oxygen gas from water● Paired fins for swimming

Grouped into 3 classes

Jawless fish

Cartilaginous fish

Bony fish

Jawless Fish

Most of this early group are now extinct, but a few remain:

Lampreys and hagfish

No jaws

Some are parasites on other fish

Lampreys

Jawless Fish

Hagfish

Secrete slime when threatened

Look like eels but belong to their own

ancient family

Cartilaginous Fish

Skeletons are made of a tough fibrous tissue called cartilage

Sharks

Skates

Rays

Bony Fish

Largest class of vertebrates - 28,000 species

Examples:

Bony Fish

Skeleton of bone

Scales

Paired fins

One pair of gills

Jaws

Reptiles

Waterproof skin

Scales

3 chambered heart

Lungs

Fluid filled eggs with leathery shells

BirdsClass Aves

● Lightweight bones - mostly hollow inside to reduce weight● Skin covered with feathers and scales● Beaks - do not chew food but their digestive systems

include gizzards, organs for grinding food● Four chambered heart● Respiratory system has extra air sacs which allow more

oxygen to move through the lungs

● Most birds make nests for eggs - hard shells● Most have stiff outer feathers for flying● They feed and care for their young● Most have unique calls or songs

Mammals

All mammals have fur or hair

Chew food using teeth

Complex digestive and nervous system

Mammary glands that produce milk for young