Question

Justify the following statements:(i) Birds, reptiles and frogs are called ‘Oviparous’.(ii) Human are ‘Viviparous’.(iii) Earth worm is a ‘hermaphrodite’.(iv) The sheep ‘Dolly’ was a clone of her mother

Answer 1

Answer:

i) Birds, reptiles and frogs are called oviparous because their mode of reproduction is by hatching of eggs and thus not going through development of embryo internally.

ii) Humans are called viviparous as embryo is developed inside their body, and gives birth after its gestation is over which is 9 months.

iii) Earthworm is a hermaphrodite as they possess reproductive organs of both males and females.

iv) Dolly was created by a cloning process called somatic cell nuclear transfer. The nucleus of a mammary cell isolated from the mother sheep was inserted into an enucleated oocyte.

This was followed by electric fusion which gave rise to blastocyst and was incorporated into a foster mother. Hence Dolly is an exact clone of her mother who donated somatic mammary cells.