Question

Which of the following characteristic features always holds true for the corresponding group of animals?
(a) Cartilaginous Chondrichthyes endoskeleton (b) Viviparous Mammalia (c) Possess a mouth Chordata with an upper and a lower jaw (d) 3 – chambered heart Reptilia with one incompletely divided ventricle

Answer 1

The right answer is (b) Viviparous Mammalia.

Humans, dogs, and cats are viviparous animals: they reproduce direct baby animals.

Viviparous animals largely differ from egg-laying animals, such as birds and most of the reptiles.

Mostly all mammals except the platypus and the echidnas are viviparous.

Only these two unusual mammals, called montremes, lay eggs.

Therefore out of all the options the option B is universally true.