Transcript Chapters 40.2-44

Chapters 40.2-44
Vertebrates
You are still responsible for reading the
chapters, learning the vocabulary, and learning the
reproductive cycles, feeding methods, and
developmental stages of the organisms in your
reading. Your final will provide you with the testing of
this material.
Chapter 40.2 and 41

Overview of Chordates
◦ Includes all vertebrates and 2 groups of animals that lack
backbones
 Notochord, dorsal nerve cord, pharyngeal pouches, and a postanal
tail

Evolution and Classification of Fishes
◦ Characteristics of 3 classes of fishes
 Agnatha = jawless fishes; Chondrichthyes = cartilaginous fishes;
Osteichthyes = bony fishes (95% are in this class)
◦ Distinguish between cartilaginous and bony fishes
 Skeletons made of cartilage (sharks, skates, and rays) = flexible,
lightweight material made of cells surrounded by tough fibers of
protein
◦ Describe the special adaptations of fishes:
 Cartilaginous: can smell, see, and detect electrical fields to detect
prey
 Bony: List the special adaptations of the bony fish
A cute addition…
Fish vs. Amphibians

Amphibian Overview
◦ Basic characteristics of
each amphibian order
 Spend part of life in
water and other part
on land
 Evolved from lobefinned fishes
 Share anatomical
similarities with fishes
including features of the
skull and vertebral
column
 Aquatic larval stage to
terrestrial adult stage
 Moist, thin skin with no
scales
 Feet lack claws and are
often webbed
 Most use gills, lungs, and
skin in respiration
 Eggs lack multicellular
membranes or shells.
 Laid in water or moist
environment
 Usually fertilized
externally
Chapter
42
Reproduction in frogs
Summarize the steps in the development
of a frog
Chapter 43

Reptile Evolution
◦ General features of reptiles
 2-loop circulatory system
 Heart has 2 atria and a single ventricle partly divided by a
septum (lizards, snakes, tuataras, and turtles); heart has 2 atria
and 2 ventricles
 Large lungs, often divided internally into several chambers
 Brain is about same size as amphibian of same size
 Jacobson’s Organ (found in all reptiles except crocodiles and
most turtles)
 Thermoregulation
 3 patterns of reproduction (based on how long the eggs
remain in the female/how she provides them with nutrition)
 Oviparity = each egg is in protective shell
 Ovoviviparity = egg is retained within the female’s body for a time;
eggs laid shortly before hatching OR may hatch within
 Viviparity = shell does not form around egg, young are retained
Chapter 43 continued

Modern Reptiles
◦ Order Chelonia
 Turtles (aquatic) and tortoises (terrestrial)
 Body covered by shell = carapace (dorsal) and plastron (ventral)
 Habitat:
◦ Order Crocodilia
 Crocodiles, alligators, caimans, and gavials.
 Heavy body and aquatic
 Habitat:
◦ Order Squamata
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Lizards and snakes
Upper jaw loosely joined to skull
Most structurally diverse
Have autonomy
Habitat:
◦ Order Rhynchocephalia
 Tuataras
 genus Sphenodon
 Spiny crest
 Hide during day and feed at night

Characteristics of Birds – class
Aves
◦ Evidence suggests that birds evolved
from ancient reptiles
 S-shaped neck, unique ankle joint,
hollow bones
 Oldest known fossil: Archaeopteryx
lithographica
 Had hollow bones and furcula, teeth,
claws and long, bony tail
◦ General features of birds
 Feathers-modified scales: provide lift
and aid in heat conservation
 Wings
 Lightweight, rigid skeleton-many are
fused to provide stability
 Endothermic metabolism-generate
heat to warm the body internally
 Unique respiratory system
 Beak
 Oviparity
Chapter 44
Chapter 44 Continued

Bird Reproduction
◦ Male: sperm is produced in 2 testes, passes through
the vasa deferentia, into cloaca
◦ His cloaca presses against her cloaca
◦ Female has 1 ovary on left side of body: egg passes to
oviduct, fertilized by sperm, leaves oviduct, receives
protective covering and shell, expelled from cloaca
◦ Eggs laid in nest
 Nest holds eggs, conceal young birds from predators, provide
shelter, and sometimes attract mate
 Eggs incubated by brood patch on underside of bird
 Hatch and remain in nest for period of time
 Precocial = active as soon as hatched; many in nest
 Altricial = hatch blind, naked, and helpless; dependent on parents
for weeks