Transcript Lesson 3 - Mammals - Mother Teresa Regional School

Lesson 3 - Mammals
Chapter 4 – Birds and Mammals
All mammals are endothermic vertebrates
that have a four chambered heart and
skin covered with fur or hair.
 Moat mammals are born alive, and every
young mammal is fed with milk produced
by organs in it’s mother’s body
 These organs are called mammary glands.
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Characteristics of Mammals
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Most mammals have teeth that are adapted
to chew their food, breaking it into small bits
that make digestion easier.
Moist mammals have teeth with four different
shapes/
Canines are pointed teeth that stab food and
tear into it.
Premolars and molars have broad, flat upper
surfaces for grinding and shredding food.
Incisors are flat-edged teeth used to bit off
and cut food.
Obtaining Food
Mammals breath in and out because of
the combined action of rib muscles and a
large muscle called the diaphragm.
 The diaphragm is located at the bottom of
the ribs.
 Like birds, mammals have a four
chambered heart and two looped
circulatory system.
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Obtaining Oxygen
Mammals are endotherms.
 They need energy in food to keep a
steady internal temperature.
 All mammals have fur or hair at some
point in their lives that helps them keep
their internal temperature stable.
 Some mammals also have a layer of fat
beneath their skin that helps them live in
colder climates.
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Keeping Conditions Stable
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Most mammals run or walk on four limbs,
but some have specialized ways of
movement. Such as hopping, swinging,
flying, gliding, and swimming.
Movement
A mammal’s nervous system coordinates
its movements.
 The nervous system also enables
mammals to learn, remember, and behave
in complex ways.
 The sense of mammals are highly
developed and adapted for the way a
species lives.
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Nervous System
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There are three main groups of mammals
– monotremes, marsupials, and placental
mammals. The groups differ in how their
young develop.
Diversity of Mammals
Egg-laying mammals.
 There are three species of monotremes –
two species of spiny anteaters and the
duck-billed platypus.
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Monotremes
Koalas, kangaroos and opossums are
some of the better known marsupials.
 Their young are born at an early stage of
development, and they usually continue
to develop in a pouch on the mother’s
body.
 Marsupials have a very short gestation
period. Ex: opossums have a gestation
period of 13 days.
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Marsupials
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Unlike a monotreme or a marsupial, a
placental mammal develops inside its
mother’s body until its body systems can
function independently.
The name of the group comes from the
placenta, which is an organ in pregnant
female mammals that passes materials from
the mother and the developing embryo.
Placental mammals are classified into two
groups on the basis of characteristics such as
how they eat and how their bodies move.
Placental Mammals
Young mammals usually stay with their
mother or both parents for an extended
period of time.
 They learn things that are important to
their survival.
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Caring for Young