Question

Identify the animal given in the picture and write features of its phylum/class.

Answer 1

The given organism in the given picture is Dolphin and it belongs to class Mammalia.

Features of class Mammalia:

1. Special feature: Presence of mammary glands (milk-producing glands) for the nourishment of young ones. Mammary glands are modified sweat glands.
2. Habitat: Mammals are omnipresent (present everywhere). These are mostly terrestrial, some are aquatic and a few are aerial and arboreal (living on trees).
3. Locomotion: Limbs are the organs of locomotion and are modified for walking, climbing, burrowing, swimming, etc.
4. Body division: Body is differentiated into head, neck, trunk, and tail. They have an external ear (pinna).
5. Body temperature: Mammals are homeotherms or warm-blooded animals.
6. Exoskeleton: It is in the form of hair, fur, nails, hooves, horns, etc.
7. Skin: Skin is glandular and has sweat glands and sebaceous (oil) glands.
8. Mouth cavity: Mammals show heterodont dentition (various types of teeth like incisors, canines, premolars and molars).
9. Circulation: Heart is ventral in position, four chambered with two auricles and two ventricles. RBCs are biconcave and enucleated (except camel). Blood is red in colour.
10. Respiration: Respiration takes place by lungs.
11. Nervous system: Brain is highly developed. The cerebrum shows a transverse band called the corpus callosum.
12. Reproduction and development: Only few mammals are oviparous. e.g. Duck-billed platypus. Some have pouches for the development of immature young ones. These are called marsupials. e.g. Kangaroo. Most of the mammals are placental and viviparous.