Looking for classes? Ksquare Career Institute, Bengaluru →
Which of the following characters is not typical of the class Mammalia -
A
Alveolar lungs
B
Ten pairs of cranial nerves
C
Seven cervical vertebrae
D
Thecodont dentition
Detailed Solution
Mammals have 12 pairs of cranial nerves, not 10.
Ten pairs of cranial nerves are found in fishes and amphibians (anamniotes).
So 'ten pairs of cranial nerves' is not typical of mammals.
Mammals do have alveolar lungs, in which gaseous exchange takes place in alveoli.
Almost all mammals have seven cervical vertebrae, whether the neck is long (giraffe) or short (whale).
Mammals have thecodont dentition: the teeth are embedded in sockets of the jaw bones.
So the character not typical of the class Mammalia is ten pairs of cranial nerves.
Ten pairs of cranial nerves are found in fishes and amphibians (anamniotes).
So 'ten pairs of cranial nerves' is not typical of mammals.
Mammals do have alveolar lungs, in which gaseous exchange takes place in alveoli.
Almost all mammals have seven cervical vertebrae, whether the neck is long (giraffe) or short (whale).
Mammals have thecodont dentition: the teeth are embedded in sockets of the jaw bones.
So the character not typical of the class Mammalia is ten pairs of cranial nerves.