1. Important characters of mammals
Presence of mammary glands , Ear pinna , 7 cervical vertebrae , Viviparity , diaphragm
2. Mammals are very alert and active.Why ?
High rate of metabolism and warm blooded nature.
3. Mammals are found throughout the earth including polar regions . Why ?
Because of their adaptations.
4.What is thecodont dentition
Teeth born in sockets of the jaws.
5. What is heterodont dentition
Four types of teeth – incisors , canines , premolars and molars.
6.What is carnassial teeth
The last premolar of the upper jaw and first molar of the lower jaw in carnivorous
Mammals work like scissors to tear flesh.
7.What is diphyodont dentition
Two sets of teeth – milk teeth and permanent teeth develop during life time.
8.In which group egg laying mammals belongs
Prototheria or monotremes.
9.In which group pouched mammals belongs
Metatheria or marsupials
10.In which group higher or placental mammals belogs.
11.Name the unfinished mammals
Egg laying mammals – retaining some reptilian characters. Egs.Echdna ( spiny anteater)
And Duck billed platypus.
12.Prototheria or egglaying mammals are called living fossils and connecting links. Why?
They retain reptilian characters.