The most unique mammalian characteristic of Class Mammalia is
Apresence of a backbone
Bpresence of mammary glands
Cpresence of hair or fur
Dability to lay eggs
Answer:
B. presence of mammary glands
Read Explanation:
Class Mammalia:
- They are found in a variety of habitats - polar ice caps, deserts, mountains, forests, grasslands and dark caves.
- Some of them have adapted to fly (Pteropus - Flying fox) or live in water.
- The most unique mammalian characteristic is the presence of milk producing glands (mammary glands) by which the young ones are nourished.
- They have two pairs of limbs, adapted for walking, running, climbing, burrowing, swimming or flying.
The skin of mammal:
- Unique in possessing hair.
- External ears or pinnae are present.
- Different types of teeth are present in the jaw.
- Heart is four chambered.
- They are homoiotherms.
- Respiration is by lungs.
- Sexes are separate and fertilisation is internal.
- They are viviparous with few exceptions and development is direct.
Examples :
- Oviparous - Ornithorhynchus (Platypus)
- Viviparous - Macropus (Kangaroo)
- Pteropus (Flying fox)
- Camelus (Camel)
- Macaca (Monkey)
- Rattus (Rat)
- Canis (Dog)
- Felis (Cat)
- Elephas (Elephant)
- Equus (Horse)
- Delphinus (Common dolphin)
- Balaenoptera (Blue whale)
- Panthera tigris (Tiger)
- Panthera leo (Lion)