Download Chapter 31 – Aves (Birds)

Chapter 30 – Class: MAMMALIA
I.
Characteristics of Mammals
A.
Hair – made of keratin protein; evolved
from scales
1.
Hair is used for:
Insulation – conserves
body heat
Camouflage
Waterproofing
Sense changes
in environment
Defense
2.
Cooling Off
 Panting: releases water from nose &
mouth, causing loss of body heat
 Sweat glands: moisture is secreted
onto skin’s surface; as moisture
evaporates, heat from body is
transferred to air
B.
Mammary Glands produce & secrete milk
that is rich in nutrients
C.
D.
4-chambered heart –
fully separates O2-rich
blood from O2-poor
blood, delivering the
maximum amount of
O2 to the body
Diaphragm – sheet
of muscle that
expands chest
cavity to get O2 into
lungs
E.
1.
Special Teeth – based on diet
Incisors – chiseled flat for
biting & cutting
2.
3.
Premolars
& Molars –
flat for
grinding &
crushing
Canines – sharp for
stabbing & tearing
F.
Endothermic
G.
Internal Fertilization
H.
2 pairs of limbs in most species – for food
gathering (opposable thumbs, wings, etc.)
I.
Highly developed brains - mammals:
1. can learn
2.
3.
are the most intelligent
animals
use tools
II.
Diversity of Mammals – 3 Subclasses, based
on method of reproduction
A.
Monotremes
1.
Lay amniotic eggs
2.
platypus, spiny anteater/echidna
3.
Found only in Australia, Tasmania,
& New Guinea – evolved after
Pangaea split up
B.
1.
2.
Marsupials
Young develop incomplete
inside mother, then in pouch
made of skin & hair – are
blind & hairless
koala, kangaroo, opossum
3.
Found mainly in Australia –
evolved before Gondwana split up
C.
Placental Mammals (90% of all mammals)
1.
Young develop inside mother’s
muscular uterus until body systems
are fully functional & can live
independently of mother’s body
2.
Placenta – organ that provides
nutrients to offspring
3.
Gestation varies by body size, but
these mammals are better protected
4.
Human, dog, horse, lion, seal, whale
5.
Found Worldwide – evolved
before Pangaea split up
III.
Orders of the class MAMMALIA
Order INSECTIVORA – shrew, mole
Order CHIROPTERA – bat
Order RODENTIA – rat, squirrel, gopher
Order LAGOMORPHA – rabbit, hare
Order EDENTATA – armadillo, sloth,
giant anteater
Order CETACEA – whale, dolphin
Order SIRENIA – manatee
Order PROBOSCIDEA – elephant
Order CARNIVORA – dog, cat, lion, bear,
seal, walrus
Order ARTIODACTYL – cow, deer (even #)
Order PERISSODACTYL – horse (odd #)
Order PRIMATES – gorilla, monkey, man