Question

What are oviparous and viviparous animals?

Answer 1

Ovipary & Vivipary is based on the site at which the foetus or embryo of an organism develops.

●Ovipary :- When the embryo develops outside the body of the female ( probably in an egg / shell )
﹏◐ eg : Birds , frog , most of the fishes , arthropods etc..

● Vivipary :- When the embryo develops inside the body of the female organism by ensuring essentials nutrients from " Plancenta "
﹏◐ eg : mammals

Answer 2

$\huge {\bf{\red{Viviparous\: and }}}$ $\huge {\bf{\red{Oviparous \:Animals }}}$

In birds, reptiles and mammals including humans, fertilisation occurs inside the female body. This is known as internal fertilisation. In animals, where the fertilisation is internal. there are different ways in which the fertilised egg develops into a new organism.

Humans and most other mammals such as cows, goats, dogs, cats, and lions give birth to fully formed young ones. The animals that give birth to young ones are called viviparous animals.

Birds lay fertilised eggs and keep them warm by sitting on them. A chick comes out of the animals. egg in due course of time. Snakes and crocodiles also lay fertilised eggs which develop into young ones. Animals that lay eggs are called oviparous animals. All frogs, lizards, fishes are also oviparous.

In oviparous animals the process of development is different from animals. After fertilisation, the zygote divides animals the process repeatedly and travels down the oviduct as in humans. However as it travels down, many protective layers are formed around it. The hard shell of a bird's egg is one such layer. After the hard shell is formed around the embryo, the hen lays the egg. The bird then sits on the egg to keep it warm. Development of the chick takes place inside the shell. I takes about 3 weeks for the embryo of a hen to develop into a chick. After the development is complete, the chick comes out by bursting open the egg shell.