Answer:
A) A transgene integrated into a heterochromatic region of the genome.
Explanation:
This is most likely the reason why the transgene is not expressed in the fifth cell line. It is likely that the transgene was integrated into a heterochromatic region of the genome. Heterochromatin consists of genetically inactive satellite sequences, and many of these are repressed to various extents. Moreover, because this is a tightly packed form of DNA or condensed DNA, it is inaccesible to polymerases and thus not transcribed.
A compound (for example: H2O)
Here, Genotype of the Purple flower can be determined by "Test Cross", in which Cross will occur between White flower and the given flower.
Case.1) If all the offspring are purple, then the Genotype of that Flower would be: PP
Case. 2) If one of the offspring is White, then the Genotype of that Flower would be: Pp
Hope this helps!