Which of the following statements about sex determination in Drosophila is false?     Males transcribe sex-lethal, females do not.     The X/A ratio controls the transcription of sex-lethal.     Double-sex RNA is spliced differently in males and females.     Transformer regulates the splicing of double-sex RNA.     Functional transformer protein is only produced in females.

How do we know that Drosophila utilizes a different sexdetermination mechanism than mammals, even though it has the same sex-chromosome compositions in males and females?

Describe how methylation and acetylation of the histones changes gene expression in eukaryotes. What groups are added? How do these processes physically affect chromatin structure? Silencing or Enhancing expression?

Explain how polytene chromosomes of Drosophila are produced and how they form a six-armed structure?

Discuss how the anterior portion of the anteroposterior axis is established in Drosophila. What aspects of oogenesis are critical in establishing this axis? What do you think would happen if the bicoid mRNA was not trapped at the anterior end but instead diffused freely throughout the oocyte?

The genes described below are part of the yeast mating signal transduction pathway that signals the presence of extracellular alpha pheromone to the nucleus. These genes are listed in the order they function in the pathway. STE3 encodes alpha pheromone receptor STE4 encodes the ß subunit of a heterotrimeric G protein STE7 encodes a protein kinase STE12 encodes a transcription factor Loss-of function-mutations in any of these genes are sterile. In addition, gain-of-function mutations can be isolated in these genes. For which gene would a loss of function mutation suppress gain-of-function mutations in any of the other three genes. STE3 STE7 STE12 STE4