Question

Animals which give birth to young ones are called as
A. Amphibious
B. Oviparous
C. Triploblastic
D. Viviparous

Answer 1

The animals are classified based on the mode of giving birth to offspring. Some animals give birth to their young ones while some lay eggs and hatch them so that new ones are born fully developed. The development of the embryo may be internal or external.

Complete answer:
There are two types of animals based on the way of producing their offspring. Some animals lay their eggs to give birth to their young ones. Such animals are called oviparous animals and the animals which do not lay eggs and give birth to developed young ones are called viviparous animals. Viviparous animals have internal development of their progeny which means that the offspring grows inside the womb of the mother. They are fed through the placenta of the mother and the exchange of oxygen and waste materials excreted by the developing foetus also takes place through the placenta of the mother. The foetus grows fully inside the womb. In oviparous animals, the mother lays eggs when it gets fertilized by the sperm of the male partner. The embryo developing inside the egg needs a suitable environment for its growth. It also needs to feed and is supplied by the contents present inside the eggshell. The egg is mainly composed of hard materials and is not easily broken. When the embryo develops fully, it hatches from the egg by itself.
So, the correct answer is Option D-‘Viviparous’.

Note: Mammals are usually classified under viviparous animals but platypus is the only animal that is a mammal and lays eggs instead of giving birth to young ones. The fertilized egg in a viviparous animal gets implanted on the placental wall of the uterus and develops there.