Main phenomenon on which genetic engineering is based is

Discovery of which made genetic engineering possible ?

Which one is not used in genetic engineering -

which is related to genetic engineering

Which enzyme is useful in genetic engineering ?

Which enzyme is useful in genetic engineering ?

Which enzyme is useful in genetic engineering ?

Which is related to genetic engineering ?

Which enzyme is useful in genetic engineering?

The enzyme which are commonly used in genetic engineering are

The step that proved to be the main challenging obstacle in the production of human insulin by genetic engineering is :