This question is about mechanisms of gene regulation in eukaryotes. a) In Drosop

Question

This question is about mechanisms of gene regulation in eukaryotes. a) In Drosophila melanogaster, Sex-lethal (Sxl) controls somatic sexual development. i. early embryos. Explain how this difference is maintained later in the life cycle Describe the regulatory mechanism that leads to the presence of Sxl protein only in female 4 marks] 16 marks] 11. b) List two RNA modifications present in eukaryotes. Describe in detail the function of one of [6 marks] these RNA modifications in a living cel c) Describe the function of two different DNA and or histone modifications present in eu 4 marks

Explanation / Answer

a. 1.Regulatory mechanism of Sxl protein involves three steps include, stimulation of XA signal, activation of establishment promotors Sxlpc by XA signal, and the effect of Sxl production on the control of Sxl auto regulation. Set of zygotic and maternal genes are required for the activation of XA signal. Model components which is required for XA signal is numerator genes Sc and Sis a and denominator genes Dpn and Da.

b. RNA modifications of eukaryotes are capping, splicing and histone mRNA processing. The process of the capping involves addition of 7 methylglucosine at the 5 prime end which is catalysed by guanosyl transferase which results in di phosphate 5 prime end. Methyltransferese transfers methyl group from s adenosyl methionine to guanine ring. This structure is called cap 0 structure. Splicing is the process of removal of introns from RNA sequences which do not code for proteins. Nucleosomes which make histones H2A, H2B, H3 and H4 are core histones. Typical histones mRNA lacks several features of eukaryotic mRNA such as poly a tail and introns.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.