Post on 27-Dec-2015
VERTEBRATESVERTEBRATES
Ch. 25 & 26Ch. 25 & 26
LifeLife
BirdsBirds MammalsMammals
What are vertebrates?What are vertebrates?
Animals with a backboneAnimals with a backbone Examples: fishes, frogs, turtles, Examples: fishes, frogs, turtles,
snakes, birds, alligators, mammals, snakes, birds, alligators, mammals, etc.etc.
Vetebra comes from the Latin word vertere, meaning “to turn”
Phylum ChordataPhylum Chordata
Chordates are named for an Chordates are named for an embryonic structureembryonic structure
– The The notochordnotochord is a flexible rod that extends is a flexible rod that extends through much of the length of the bodythrough much of the length of the body
Most chordates are vertebrates, Most chordates are vertebrates, butbut
There are two groups of There are two groups of invertebrates that are chordates invertebrates that are chordates (tunicates & lancelets)(tunicates & lancelets)
Vertebrates are ChordatesVertebrates are Chordates
Vertebrates are animals with Vertebrates are animals with a skull and a a skull and a backbonebackbone– An endoskeletonAn endoskeleton
In vertebrates, only remnants of the notochord In vertebrates, only remnants of the notochord remainremain
Example: the cartilage discs in your Example: the cartilage discs in your backbonebackbone
Most vertebrates have paired limbsMost vertebrates have paired limbs
Hinged JawsHinged Jaws– Importance?Importance?
Other important featuresOther important features
VertebratesVertebrates
Hagfish and lampreysHagfish and lampreys Do not have hinged jaws or paired limbsDo not have hinged jaws or paired limbs
VertebratesVertebrates
FishesFishes– Have hinged jawsHave hinged jaws– aquaticaquatic
Tetrapods:Tetrapods:
Amphibians, reptiles, birds, Amphibians, reptiles, birds, mammalsmammals
Tetrapods (“four footed”) have 2 sets Tetrapods (“four footed”) have 2 sets of paired limbsof paired limbs
This allowed them to??This allowed them to??
Snakes are tetrapods!Snakes are tetrapods! They evolved to become leglessThey evolved to become legless
ActivitiesActivities
1) Finish grasshopper dissection & 1) Finish grasshopper dissection & turn in.turn in.
2) pHSuccessnet.com2) pHSuccessnet.com– Ch. 25 webquestCh. 25 webquest– Activity 25.1Activity 25.1
FISHESFISHES
2 Categories:2 Categories:
Cartilaginous fishesCartilaginous fishes – Chondrichthyes – Chondrichthyes Skeletons are flexible and made entirely of Skeletons are flexible and made entirely of
cartilagecartilage Sharks and raysSharks and rays
Bony fishesBony fishes Skeletons contain bone hardened by calcium Skeletons contain bone hardened by calcium
depositsdeposits
The 1st jawed vertebrates.
Bony FishesBony Fishes
Stiff skeleton made of calciumStiff skeleton made of calcium Gills to extract OGills to extract O2 2 from waterfrom water
– Operculum- flap that covers the gillsOperculum- flap that covers the gills
- - pumps water over the gillspumps water over the gills Lateral line systemLateral line system
Bony FishesBony Fishes
Stiff scales made of boneStiff scales made of bone
The outer mucus allows fish to glide The outer mucus allows fish to glide more easily through the watermore easily through the water
Most are carnivoresMost are carnivores Some feed upon plankton or algae (seaweed)Some feed upon plankton or algae (seaweed)
Bony FishesBony Fishes
Air SacAir Sac– ““swim bladder”swim bladder” makes fish more buoyant makes fish more buoyant– Also aids in hearing by transmitting vibrationsAlso aids in hearing by transmitting vibrations
Heart ---> 2 ChambersHeart ---> 2 Chambers The ventricle (1) pumps blood to the gillsThe ventricle (1) pumps blood to the gills The atrium (2) receives blood returning from the bodyThe atrium (2) receives blood returning from the body
2 Chamber Heart2 Chamber Heart
One way circuitOne way circuit
Very basicVery basic
Much slower than Much slower than
land vertebratesland vertebrates
VideoVideo
Life Science: Fish and Amphibians Life Science: Fish and Amphibians
ReviewReview
1) What is the major difference 1) What is the major difference between cartilaginous and bony between cartilaginous and bony fishes?fishes?
2) Describe the function of the lateral 2) Describe the function of the lateral line system.line system.
3) List the general characteristics of 3) List the general characteristics of bony fishes.bony fishes.
4) List and contrast the 3 classes of 4) List and contrast the 3 classes of bony fishes.bony fishes.
Perch DissectionPerch Dissection
Perch DissectionPerch Dissection
The First TetrapodsThe First Tetrapods AmphibiansAmphibians are are
descendants of four descendants of four limbed ancestors that limbed ancestors that were fully aquatic 400 were fully aquatic 400 myamya– Limbs and legs evolved in Limbs and legs evolved in
fishes– moved to land (50 fishes– moved to land (50 million years)million years)
Leg-like limbs allowed for Leg-like limbs allowed for movement through dense movement through dense marine vegetationmarine vegetation
The First TetrapodsThe First Tetrapods
AcanthostegaAcanthostega have gill structures, have gill structures, but amphibian-like limbsbut amphibian-like limbs
AmphibiansAmphibians
AmphibiosAmphibios= “living a double life” in Greek= “living a double life” in Greek Many live in their larval stage in water and Many live in their larval stage in water and
adult stage on landadult stage on land Eggs do not have shells so are easily dried outEggs do not have shells so are easily dried out Water is often necessary for laying eggsWater is often necessary for laying eggs
Adults generally:Adults generally: Have LungsHave Lungs Have moist skin without Have moist skin without
scalesscales
Stage of DevelopmentStage of Development Tadpoles --> the larvae of amphibiansTadpoles --> the larvae of amphibians
Legless aquatic plant-eaters with:Legless aquatic plant-eaters with: Gills, lateral line system, long tailGills, lateral line system, long tail
Metamorphosis into adult form leads to:Metamorphosis into adult form leads to: Lungs in place of gillsLungs in place of gills EardrumsEardrums No lateral line systemNo lateral line system 4 legs4 legs
***Some amphibians do not have a ***Some amphibians do not have a terrestrial stage, some amphibians do not terrestrial stage, some amphibians do not have an aquatic stagehave an aquatic stage
Other characteristicsOther characteristics
Moist skin often assists lungs with Moist skin often assists lungs with gas exchangegas exchange
May also contain poison glandsMay also contain poison glands
Amphibians have a 3-chambered Amphibians have a 3-chambered heartheart
Remember fish have 2 chambered heartRemember fish have 2 chambered heart
Allows for Allows for 2 pathways2 pathways of blood flowof blood flow
One to the lungs and One to the lungs and skin for gas exchangeskin for gas exchange
One to the other One to the other tissuestissues
Advantage??Advantage??
The Atria collect blood The Atria collect blood returning to heartreturning to heart
Ventricle pumps blood Ventricle pumps blood outout
Amphibian DiversityAmphibian Diversity
about 8% of vertebratesabout 8% of vertebrates
Frogs Frogs – insect eatersinsect eaters– Toads are terrestrial frogsToads are terrestrial frogs
Salamanders Salamanders – insect eatersinsect eaters
Caecilians Caecilians Legless & blind; burrow in soilLegless & blind; burrow in soil
VideoVideo
Life Science: Fish and Amphibians Life Science: Fish and Amphibians
General Characteristics of General Characteristics of Amphibians?Amphibians?
1)1) 2)2) 3)3) 4)4) 5)5)
What if they were forced to live on What if they were forced to live on land and have no access to water? land and have no access to water?
AMNIOTESAMNIOTES
Amniotes- reptiles, birds, mammalsAmniotes- reptiles, birds, mammals
General Characteristics:General Characteristics:– Live on land (do not need water)Live on land (do not need water)– Amniotic eggAmniotic egg– Internal fertilizationInternal fertilization– Water-tight skin Water-tight skin
Amniotic EggAmniotic Egg
Waterproof egg with a shellWaterproof egg with a shell Amnion- protects embryo from drying Amnion- protects embryo from drying
outout
Water-tight SkinWater-tight Skin
Enriched with keratinEnriched with keratin– Prevents dehydrationPrevents dehydration
Reptiles- scalesReptiles- scales Birds- feathersBirds- feathers Mammals- nails, hair, hornsMammals- nails, hair, horns
ReptilesReptiles
Reptile CharacteristicsReptile Characteristics
Water-tight, scaly skin that Water-tight, scaly skin that moltsmolts LungsLungs Lay eggsLay eggs Cold-blooded Cold-blooded
(ectotherms)(ectotherms)
Komodo Dragon Hunting a Komodo Dragon Hunting a Water BuffaloWater Buffalo
http://dsc.discovery.com/tv/life/http://dsc.discovery.com/tv/life/episodes.html episodes.html
BIRDSBIRDS
Ancestor- dinosaurAncestor- dinosaur Endothermic amniotesEndothermic amniotes Adaptations for flight: Adaptations for flight:
– Wing shapeWing shape– Feathers (also for insulation) Feathers (also for insulation) – Several weight-reducing featuresSeveral weight-reducing features
Review of Frog DissectionReview of Frog Dissection
Where is the tympanic membrane?Where is the tympanic membrane? How can you tell a male from a How can you tell a male from a
female?female? What is the cloaca?What is the cloaca? What is the purpose of the fat What is the purpose of the fat
bodies?bodies? What are 3 differences between What are 3 differences between
reptiles and amphibians?reptiles and amphibians?
Wing ShapeWing Shape
Airfoil-shaped wingsAirfoil-shaped wings
Air-sac SystemAir-sac System
Function with lungs for respirationFunction with lungs for respiration Helps supply high level of O2 that Helps supply high level of O2 that
supports a high metabolism. supports a high metabolism. Also reduces density of birdAlso reduces density of bird
Weight-Reducing FeaturesWeight-Reducing Features
Air-sacs Air-sacs Honey-combed bonesHoney-combed bones Absence of some internal organsAbsence of some internal organs
Circulatory SystemCirculatory System
Efficient oxygen deliveryEfficient oxygen delivery 4-chambered heart4-chambered heart
– Adaptation for active, endothermic Adaptation for active, endothermic lifestylelifestyle
MAMMALSMAMMALS
Mesozoic era- evolved from mammal-Mesozoic era- evolved from mammal-like reptiles, therapsids like reptiles, therapsids
Mammal CharacteristicsMammal Characteristics
EndothermicEndothermic Mammary glands- milkMammary glands- milk Hair- insulationHair- insulation Lungs with diaphragmLungs with diaphragm 4-chambered heart4-chambered heart Internal fertilization Internal fertilization
Mammal DiversityMammal Diversity
Monotremes- lay eggs, cloacaMonotremes- lay eggs, cloaca
Mammal DiversityMammal Diversity
Marsupials- “pouched mammals”Marsupials- “pouched mammals”
Mammal DiversityMammal Diversity
Placental Mammals- Embryo Placental Mammals- Embryo completes development within the completes development within the uterus; placenta forms & feeds uterus; placenta forms & feeds embryo embryo