The development and use of transgenic farm animals has not progressed as fast as the development of transgenic plant species. this may be due to all of reasons given except a) inadequate technology. b) consumer safety issues. c) susceptibility to disease. d) possibility of infertile animals. 4)

 A) inadequate technology

Explanation:

Transgenic organisms are those organisms which are genetically modified by human beings. The knowledge and practice of genetic engineering is used to modify the genome of the organism, by either  removing the defective part of it or by adding genes of other organisms so as to obtain desired qualities in them. Animals as compared to plants are more complex organisms as they probably perform more functions like hearing, watching, locomotion and other. Also the plants are abundantly available and several plants can be obtain by vegetative propagation for experimenting the genetic manipulation. It is quiet difficult to generate an entire animal by tissue culture for genetic manipulation. Also it is bit risky and technologically challenging to experiment such manipulations on live animals.

On the basis of above explanation A) inadequate technology is the correct option.

In homeostasis fashion, cells undergo balanced cell division and programmed cell death (apoptosis) through regulated signalling.This maintains tissue integrity. On the one hand, Proto-oncogenes promotes cells proliferation. On the other hand, tumors suppressors inhibit cell growth and division especially in cells with damaged dna.
Therefore mutations on these oncogenes could result to uncontrolled cell proliferation. Cancer cells also overexpress angiogens that results to proliferation of blood vessels in tumors. This contributes to their metastasis in the body.