Write down the characteristics of Mammalia? What are its groups?
Characteristics: -
i) Highly advanced animals are included in this group.
ii) Man is also a mammal.
iii) Their body is covered with hairs. But in few some areas are restricted by
hairs.
iv) Their skin is provided with sweat glands, scent glands, sebaceous glands
and mammary glands.
v) Fleshly external ears are present.
vi) Moveable eyelids are present.
vii) Two sets of teeth are present. Milk teeth are replaced by permanent
teeth.
viii) Brain if highly developed.
ix) Twelve pairs of cranial nerves are present.
x) Circulatory system has four-chambered heart.
xi) Sexes are separate.
xii) Most of them have internal fertilization and fetus develop inside the body
of female.
xiii) Female give birth to their children.
xiv) They feed their children by giving milk from mammary glands.
xv) They are worm blooded animals. They can maintain their body
temperature as per environment.
Groups of Mammals: -
There are three groups of mammals.
i) Egg Laying mammals.
ii) Pouched mammals.
iii) Placental mammals.