1) Using specific exs describe how variations in DNA sequence between individuals can lead to risk of disease. Describe how a range of techniques have been adapted to detect such sequence variations in the diagnostic and forensic settings.

2) Describe how the various molecular mechanisms act to regulate transcription of the genes within the tryptophan operon of E. coli.   

3) Gene expression must begin with the process of transcription

a)  Describe the promoter motifs commonly associated with eukaryotic protein-coding genes, and describe their influence on transcription

b) What are the roles of the different transcription factors that are involved in the transcription of eukaryotic protein-coding genes?

c) How do the function and mechanism of enhancers differ from promoters?

4) Describe what effects epigenetic modifications such as methylation and acetylation can have in eukaryotic cells, and how these modifications are added or removed from chromatin. 

5) The human genome project has revealed that the majority of the genome is ‘junk’.

a)  Describe the ways in which a genome can be sequenced

b) A significant proportion of the ‘junk’ DNA in the human genome is transcribed into RNA. Using specific exs describe whether this non-codingRNA plays a biological function.  

6) DNA damage can occur spontaneously or be induced by external factors. Describe the types of DNA damage caused by external factors and howthey are repaired in prokaryotes and eukaryotes.

7) Forensic analysis of DNA involves polymorphisms.

a) Define polymorphisms.

b) Describe the nature of the three types of polymorphism that have been routinely used in forensic analysis to date.

c) describe, using a suitable named ex, how a polymorphism may influence disease and health.

8) Describe how the various molecular mechanisms act to regulate transcription of the genes within the lactose operon of E. coli.

9. Transcription of a eukaryotic protein-coding gene is accompanied by multiple steps that modify the transcript. Describe the following processes in detail, indicating their role in gene expression.

a) Addition of the universal cap.

b) Intron splicing.

c) Polyadenylation.

10) Describe how the structure of chromatin and chromosomes facilitates the following functions:

a) DNA packaging.

b) Regulation of gene expression.

c) Replication at the ends of chromosomes and the prevention of translocations.

11) The ability to sequence DNA has led to a revolution in molecular biology.

a) Describe the principles of DNA sequencing.

b) A single sequencing reaction yields at best 1500 bases of good sequence data, yet the human genome is billions of base pairs long. Describe the ways in which laboratory and bioinformatics techniques can be combined to overcome this limitation allowing entire genomes to be sequenced.

c) describe how laboratory and bioinformatics approaches can be used to analyse the functions of genes.

12) Transcriptional analyses of eukaryotic cells reveal widespread production of RNA. Using specific exs describe how:

a) microRNAs are able to influence gene expression.

b) Long non-coding RNAs are able to influence epigenetics and nuclear structure.

c) Long non-coding RNAs are able to interact with miRNAs to regulate cellular processes.

13. Many bacterial genes show adaptive regulation of their transcription.

a) How is the lac operon regulated by the sigma factor?

b) How is the lac operon regulated by lactose?

c) How is the lac operon regulated by glucose?

d) How is the mRNA from this operon translated into proteins.

14) The transcription and replication of DNA requires a multitude of protein complexes

a) Describe the events that occur during the initiation of transcription of eukaryotic protein-coding genes

b) Highlight what events and components are similar during the initiation of transcription in prokaryotes

c) Outline the similarities and difference between the function and mechanisms of RNA polymerase and DNA Polymerase.

15) DNA damaga can be spontaneous or can be ‘Induced by external agents
a) What are ‘spontaneous’ mutations? Give exs of causes of spontaneous mutations and the kinds od DNA damage they cause

b) What are ‘Induced mutations? Give exs of causes of Induced mutations and the kinds of DNA damage they cause

c) Give exs of how DNA damage can be beneficial or disadvantageous to eukaryotic organisms.

16) One of the greates challenges following the human genome project is to understand how genes are regulated and what functions they perform.

a) Define the terms ‘Transcriptomics’ and ‘transcriptome’. Outline the methods that can be used to study the transcriptome and give an ex ofwhat this can tell us about the function of genes

b) How can bioinformatics be used to predict potential functions of genes?

c) describe the laboratory approaches available to alter the expression of genes and give specific exs of how these can be used to test thefunction or role of genes in disease.

17) DNA must be extensively folded in order to fit inside a nucleus that is less than 10 um in diameter.

a) Describe how DNA is folded into chromatin structures of increasing compaction and how chromosome are organised within the nucleus

b) using specific exs describe how chromatin structure, chromatin modifications and gene regulation are functionally linked

18)” Most of the genome does not code for protein, therefore 99% of the human genome is junk that serves no purpose”. With specific reference to exs long and short non-coding RNAs discuss whether you agree with this statement. In your answer you should describe the roles and mechanisms of these RNA molecules.