VertebratesFishes, Amphibians, Birds, Reptiles,

Mammals

Section 30-1

Nonvertebratechordates

FishesAmphibians

ReptilesBirds

Mammals

Invertebrate ancestor

Chordate Cladogram

Nonvertebrate Chorodate

• Choradate– Dorsal hollow nerve cord– Notochord– Pharyngeal pouches– Tail that extend beyond anus

• Nonvertebrate Chorodates– Tunicates and Lancelets

Section 30-1

Muscle segments

TailAnus

Pharyngeal pouches

Mouth

Hollownerve cord

Notochord

 The Generalized Structure of a Chordate

b

3 Characteristics of all Vertebrates

1. Endoskeleton. Supports larger animal size. Grows with animal (No molting!)

2. Backbone and cephalization. Well-developed brain with sensory organs. Earliest vertebrates were called ostracoderms.

3. Closed circulatory system with multi-chambered heart. 3- or 4-chambered heart allows blood to be separated

into oxygenated or deoxygenated. More efficient delivery of oxygen to the body.

Endotherms and Ectotherms

• Ectotherm: Temperature is regulated by external environment.– Fish, amphibians, reptiles

• Endotherm: Body temperature is regulated by internal processes.– Mammals, birds

Section 33-2

Environmental Temperature (°C)

Bo

dy

Tem

per

atu

re (

°C)

Temperature Control in Chordates

Section 33-1Diversity of Chordates

Characteristics of Fishes• Agnatha (Jawless

Fish)• Endoskeleton: Cartilage (no

jaw)• Respiratory: Multiple Gill

Openings• Circulatory: 2 chambered

heart• Reproduction: External

Fertilization and development

• Examples: Lamprey, Hagfish

• Chondrichthyes (Cartlagenous Fish)

• Endoskeleton: Cartilage• Respiratory: Multiple Gill

Openings• Circulatory: 2 chambered

heart• Reproduction: External

Fertilization (internal for sharks) and development

• Examples: Sharks, Skates, Rays

Section 30-2

Bulbus ArteriosusVentricle

AtriumSinus Venosus

Bodymusclecirculation

Digestivesystemcirculation

Gills

Heart

Brain andhead

circulation

Oxygen-rich blood

Oxygen-poor blood

Circulation in a Fish

Oxygen-poor bloodfrom the veins collects in the sinusvenosus.

Blood enters theatrium and flowsto the ventricle.

The ventricle pumps blood into the bulbus arteriosus.

The bulbus arteriosus moves blood into the ventral aorta and toward the gills.

• Agnatha: • Chondrichthyes:

Osteichthyes (Bony Fish)

• Endoskeleton: Cartilage and Bone

• Respiratory: One Gill Openings

• Circulatory: 2 chambered heart

• Reproduction: External Fertilization and development

• Examples: Trout, Cod, Salmon

Characteristics of Amphibians

• Endoskeleton: Cartilage and Bone

• Respiratory: Gills, Skin, Lungs

• Circulatory: 3 chambered heart

• Reproduction: External Fertilization and development

• Examples: Frogs, Salamanders

Amphibians: Energy and Wastes

• A frog’s skin “breathes” – it must be kept moist.

• 3-Chambered Heart, Double-looped circulatory system. – What is that? Why is that a good thing?

• Metamorphisis: teeth/jaws, gills turn into lungs, circulatory system changes

• Kidneys regulate the amount of water in the frog.– In water excrete, on land retain.

Section 30-3

Adult FrogAdult Frog

Young FrogYoung Frog

Fertilized EggsFertilized Eggs

TadpolesTadpoles

Adults are typically ready tobreed in about one to two years.Adults are typically ready tobreed in about one to two years.

Frog eggs are laid in water andundergo external fertilization.Frog eggs are laid in water andundergo external fertilization.

The eggs hatch into tadpoles a few days to several weeks later.

The eggs hatch into tadpoles a few days to several weeks later.

Tadpoles gradually grow limbs, lose their tails and gills, andbecome meat-eaters as they develop into terrestrial adults.Tadpoles gradually grow limbs, lose their tails and gills, andbecome meat-eaters as they develop into terrestrial adults.

The Life Cycle of a Frog

Characteristics of Reptiles

• Endoskeleton: Cartilage and Bone• Respiratory: Lungs• Circulatory: 3 chambered heart• Reproduction: Internal and External

Fertilization and development• Examples: Snakes, Turtles• Ectotherms.

– How does a reptile regulate its body temperature?

Rafekie

The Amniotic Egg (Figure 26.4)

• Embryo: connected to Yolk by a stalk.

• Yolk: food source.

• Amnion: fluid that protects the embryo.

• Chorion: regulates gas exchange.

• Shell: Waterproofs, protects. The shell is porous (gas can exchange through it).

• Allantois: stores wastes.

Section 31-1

AllantoisEmbryo

Shell

Amnion

Chorion

Yolk sac

 The Amniotic Egg

The chorion regulatesthe transport ofoxygen from thesurface of the eggto the embryo andthe transport ofcarbon dioxide,one product ofrespiration, in theopposite direction.

This baglike structurecontains a yolk thatserves as a nutrient-richfood supply for the embryo.

The amnion is a fluid-filled sacthat surrounds and cushionsthe developing embryo. Itproduces a protected, wateryenvironment.

The allantois stores thewaste produced by theembryo. It also servesas a respiratory organ.

Characteristics of Birds (Aves)• The one reptilian characteristic of birds

is their scale-covered legs.• Endoskeleton: Cartilage and Bone• Respiratory: Lungs• Circulatory: 4 chambered heart• Reproduction: Internal Fertilization and

External development• Examples: Birds

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.

 The Digestive System of a Pigeon

2

You Eat Like A Bird…

• Endotherms – requires a lot of energy to maintain their high metabolism.

• Feathers – trap body heat.

• Unique respiratory system – air flows one-way.

• Crop Gizzard Intestines.– Figure 26.18.

Characteristics of Mammals• Endoskeleton: Cartilage and Bone• Respiratory: Lungs• Circulatory: 4 chambered heart• Reproduction: Internal Fertilization and development• Examples: Humans, Whales . . . • SPECIAL CHARACTERISTICS:

– Endotherms – hair.– Mammary glands – produce milk.– Large, well-developed brains.

Variety of Mammals• Size

– Smallest: shrew (weighs less than a dime)

– Largest: whale (100,000 kg; 32 elephants)

• Speed– Slowest: Two-toed sloth (1

meter/15 seconds)– Fastest: Cheetah (400

meters/15 seconds)– Humans (150 meters/15

seconds)

• Environments

Mammals: Movement and Energy

• High-speed running: long bones and flexible hip and shoulder joints.

• Eat a variety of foods: different teeth structures.

• Diaphram: More gas exchange.

• Air sacs: increased surface area for gas exchange.

Section 32-1

CARNIVORE HERBIVORE

Molars crush and grind food. The ridged shape of the wolf’s molars and premolarsallows them to interlock during chewing, like the blades of scissors. The broad,flattened molars and premolars of horses are adapted for grinding tough plants.

Chisel-like incisors are used forcutting, gnawing, and grooming.

Canines are pointed teeth. Carnivoresuse them for piercing, gripping, and tearing.In herbivores, they are reduced or absent.

Jaw jointJawjoint

WolfHorse

The Jaws and Teeth of Mammals

Mammals: Types of Life Cycles

• Monotremes: Reproduce by laying eggs (duck-billed playtpus).-

• Marsupials: Give birth to small, immature young that then further develop inside the mother’s external pouch (kangaroo).

• Placental mammals: Babies develop inside the mother’s body (95% of all mammals).

 The PlacentaSection 39-4

The Success of Mammals

• Well-developed cerebrum: The largest part of the brain; makes processing information and learning possible.

• Care of the Young: Development inside the mother; care of the young for the first year(s) of their life.

Section 33-3

Double-Loop Circulatory SystemSingle-LoopCirculatory System

FISHES MOST REPTILES CROCODILIANS, BIRDS,AND MAMMALS

The Circulatory Systems of Vertebrates

Section 33-3

Esophagus

Stomach

Intestine

Liver

Gallbladder

Pancreas

Cloaca

Crop

Gizzard

Cecum

Rectum

Shark Salamander Lizard Pigeon Cow

The Digestive Systemsof Vertebrates