Q- Enlist four peculiar characters of Mammalia.
Answer- There are many peculiar characters of Mammalia. The four main peculiar characters of Mammalia are as follows:
1. The skin of mammals contains oil glands and sweat glands.
2. Mammals have a hairy exoskeleton.
3. All the mammals have 4 chambered heart and RBC are biconcave as well as denucleated.
4. The testis of mammals lies in scrotal sac and females in mammals are viviparous.