Question

46. You are studying development in fruit flies. You find that when proteins X, Y, and Z are normally expressed, the flies develop normally. However, when you remove Z, the body plan is disrupted and the fly grows 12 legs instead of 6. Which is the most likely function for Z?

1. DNA polymerase
2. RNA polymerase
3. Transcription factor
4. Helicase
5. Histone

Answer 1

DNA polymerase replicates the DNA, RNA polymerase synthesis RNA using DNA as the template, Helicase separates the two strands of DNA during replication, if helicase is mutated DNA cannot be replicated. if the genes encoding RNA polymerase, DNA polymerase or helicase are mutated such that it becomes non-functional the organisms cannot survive.

DNA is wrapped around the histone octamers to form nucleosomes if histones are mutated DNA cannot be packed in the nucleus and cells with null mutations in the histones cannot survive.

Transcription factors activate or repress the transcription of the gene, Z is a transcription factor that inhibits the expression of legs in some segments of the body.

so the answer is c) transcription factor.