The unique mammalian characteristics are:
- pinna, monocondylic skull and mammary glands
- hairs, tympanic membrane and mammary glands
- hairs, pinna and mammary glands
- hairs, pinna and indirect development
Solution
Class: Mammalia:
- They are homoiothermous.
- The skin has hairs and glands.
- External ears or pinnae are present.
- Respiration is by lungs.
- Heart is four chambered.
- They have mammary glands by which the young ones are nourished.
- Sexes are separate and fertilisation is internal. They show direct development.
Asked in: NEET 2023 (All India)