Question

The transgenic animals are those which have
A) Foreign RNA in all its cells
B) Foreign DNA in some of its cells
C) Foreign DNA in all its cells
D) Both A and C

Answer 1

Transgenic animals are animals in which foreign genes are deliberately inserted into the genome of an organism. The insertion is carried out through pronuclear microinjection and then further the cells divide mitotically forming a complete individual.

Complete answer:
Transgenic organisms are transformed by introducing novel genes into their genome. The cloned DNA sequences are inserted into the pronuclei of a fertilized egg through microinjection, nuclear transfer in somatic cells or cloning. Subsequently, the implantation of this egg is carried out into the oviduct of a surrogate mother. Further, mitotic division is carried out in the fertilized egg and the whole organism is formed. Thus, due to mitotic division, all the cells will have the transferred gene which is also known as transgene. The transgenic animals thus produced can be used in xenografting and in production of genetically engineered hormones for increasing production of meat and enhancing milk yield
Mice, Xenopus, Drosophila and some of the species of fishes are the transgenic animals which have been produced by employing this recombinant DNA technology.
Moreover, the genetic material of animals is DNA so RNA based options are incorrect and as the cells carrying foreign genes divide mitotically.

So the correct answer is option “C” that is the transgenic animals are those which have foreign DNA in all its cells.

Note: Transgenic animals have been widely used in the field of biotechnology. They are used in medical research, in toxicology for detecting toxicants, in developmental genetics of mammals, in analysis of gene expression regulation, in pharmaceutical industries for development of drugs and for testing their efficacy, in pharmaceutical protein production and in aquaculture.