Take a guess…

Which type of animal are most vertebrates?

Chordates

Chordate Example:

Mrs. Holden’s 17 year old childhood pet cat “Mookie” (class Mammalia) after a trip

to the groomer for a “lion cut”…

Trends in animal evolution- as animals get more advanced they have more features than the prior phylum

PHYLUM CHORDATA

4 characteristics present AT SOME TIME during life cycle1. Dorsal, hollow nerve cord

2. Notochord – long, supportive rod, below nerve cord*

3. Pharyngeal gill slits – in neck or throat region

4. Post-anal tail – extends beyond anus

Nonvertebrate ChordatesTwo groups do NOT have backbones:

1. Tunicates:filter feeders, larval form has chordate characteristics, adults do not2. Lancelets:small, fish-like, live on sandy

ocean bottom

Chordate OriginsMany studies suggest that the most ancient

chordates were closely related to echinoderms

Most Chordates are Vertebrates…

Vertebrate: a chordate that has a strong supporting structure called the vertebral column or backbone which is made up of bony or cartilaginous vertebrae

In vertebrates, the dorsal, hollow nerve cord is the spinal cord

Vertebrates have an endoskeleton which grows as the org grows, and is made up of living cells which produce non-living material

Chordate Diversity

PHYLUM CHORDATA – 7 CLASSESCLASSES

CLASS AGNATHA – jawless fishCLASS CHONDRICHTHYES –

cartilaginous fishCLASS OSTEICHTHYES – bony fishCLASS AMPHIBIA - amphibiansCLASS REPTILIA - reptilesCLASS AVES - birdsCLASS MAMMALIA - mammals

Figure 34.8 A hagfish

Agnatha

Figure 34.11 Cartilaginous fishes (class Chondrichthyes): Great white shark (top left), silky shark (top right), southern stingray (bottom left), blue spotted stingray (bottom right)

Chondrichthyes

Figure 34.13 Anatomy of a trout, a representative ray-finned fish

Osteichthyes

Figure 34.18 “Dual life” of a frog (Rana temporaria)

Amphibia

Figure 34.24 Extant reptiles: Desert tortoise (top left), lizard (top right), king snake (bottom left), alligators (bottom right)

Reptilia

Section 31-2

Esophagus

Crop

Liver

Firstchamberof stomach

Gizzard Smallintestine Cloaca

Pancreas

Air sac

KidneyHeart

Lung

Brain

When a bird eats,food moves downthe esophagus andis stored in the crop.

1

As digestion continues,the food moves throughthe intestines.

4

Undigested food isexcreted through thecloaca.

5

Large intestine

The muscular wallsof the gizzard squeezethe contents, while small stones grind the food.

3

Moistened food passes to the stomach, a two-part chamber. The first chamber secretes acid and enzymes. The partially digested food moves to the second chamber, the gizzard.

Figure 31–14 The Anatomy of a Pigeon

2

Aves

Figure 34.37 Apes: Gibbon (top left), orangutan (top right), gorilla (bottom left), chimpanzee (bottom right)

Mammalia

Evolutionary Trends in VertebratesFrom Water to Land

Land specific adaptations Overcome problems posed by

living on landFrom Simple to Complex

More organized systemsMore efficient systems Increase in size of systemsAppearance of successful

adaptations – such as jaws and paired appendages – has launched adaptive radiations in chordate groups

Temperature Control in Chordates

Notice as the environment temperature changes, so does the temperature for certain ectothermsFish,

Amphibians

The Digestive System of Chordates

Note differences between carnivores and herbivores!

Which has a straighter track?

Which has a larger liver?

Which has a longer intestine?

Chordate Respiration

Aquatic chordates – gillsLand vertebrates - lungs

Chordate Circulation

Those that use gills for respiration have a single-loop circulatory systemBlood travels from the heart to the gills, then to the rest of

the body, and back to the heart in one circuit

Those that use lungs for respiration have a double-loop circulatory system1st loop carries blood between the heart and lungs, oxygen

poor blood from the heart is pumped to the lungs, while oxygen rich blood from the lungs returns to the heart

2nd loop carries blood between the heart and the body – oxygen rich blood from the heart is pumped to the body, while oxygen poor blood from the body returns to the heart

Double-Loop Circulatory SystemSingle-LoopCirculatory System

FISHES MOST REPTILES CROCODILIANS, BIRDS,AND MAMMALS

Circulatory Systems of VertebratesWhich type of heart prevents oxygen poor blood from mixing with oxygen rich blood?

Chordate Hearts

Chambers and partitions that help separate oxygenated and deoxygenated blood traveling in the circulatory systemGilled vertebrates: 2 chambered heartsAmphibians: 3 chambered heartsReptiles: 3 chambered hearts with partitionsBirds, mammals, crocodiles: 4 chambered

hearts that are completely partitioned

Chordate ExcretionHow to get rid of wastes without losing too

much water?Fishes and aquatic amphibians:

Excrete ammonia directly from gills, skin via diffusion

Mammals, land amphibians, and cartilaginous fishes:Ammonia is changed into urea before excreted using

kidneys

Reptiles and birds:* saves most waterAmmonia is changed into uric acid before excretion

through kidneys

Chordate ResponseNonvertebrate chordates have a relatively simple nervous

system with a mass of nerve cells that form a brainVertebrates have a more complex brain with distinct regions,

each with a different function

Chordate Movement

Nonvertebrate chordates lack bones but have muscles for movement

The skeletal and muscular systems support a vertebrate’s body and make it possible to control movement

Chordate ReproductionOviparous (eggs develop outside mother’s body)Unprotected egg

Most fishes and amphibiansAmniotic egg

Some reptiles, birdsOvoviviparous (eggs develop within the mother’s

body)Sharks, some reptiles

Viviparous (born alive)* most advancedMost mammals

AKS Log Book

Use the notes and CP Ch 33Answer question 6Some of the Vocab will NOT be in the

back of the book!