Question
Answers

Egg laying animals are known as
A) Viviparous
B) Oviparous
C) Sterile
D) Hermaphrodite

Answer Verified Verified
Hint:These animals lack placenta and so lay eggs. The yolk acts as stored food for the developing organisms. Most fishes, amphibians, reptiles and birds lay eggs.

Complete answer:
After fertilisation, the zygote which is formed undergoes further development to form embryos. This is known as Embryogenesis. Embryonic development is a complete process that involves cell division and cell differentiation.Depending on development of zygote inside or outside the body of the female parent, organisms are classified as oviparous or viviparous.

 Now let us look into the given options
>Oviparous organisms lay eggs and the yolk inside the egg acts as stored food for the developing embryo. Examples are sharks, bony fishes, frogs, etc. In some oviparous organisms, the fertilised eggs are covered by a hard calcareous shell or a leathery coat. Examples are birds and reptiles.
>In viviparous organisms, development of fertilized eggs into embryos takes place within the uterus of the female parent. The developing embryo receives nourishment from the mother’s blood through placenta. Examples are humans.
>There are certain animals that are ovoviviparous also (this is considered to be a link between oviparous and viviparous). In these organisms, the eggs are incubated within a modified portion of the oviduct called a uterus and the young ones are born alive after hatching. The complete development cannot take place inside the female body because the placenta is short lived. Many species of sharks show this phenomenon.
>Hermaphrodite animals are those which bear male and female sex organs in the same body. Examples of hermaphrodite are Earthworms.
>Sterile animals are those animals that are not able to produce offspring. Hybrid animals are generally sterile. Example is Mule. This is a hybrid between horses and donkeys and is sterile.
Hybrid animals are generally sterile because the sex cells are not viable.

Thus the correct answer is Option B.

Note:Viviparous animals are considered to be more evolved than oviparous because viviparity allows the offspring to develop inside the female body. Thus they are protected from harsh environmental conditions and predators.
The main feature that led to development of viviparity was development of placenta which was not seen in oviparous organisms.