January 2023 Genetics & Gene Regulation Practice Tutorial PDF

January 2023 intake prac1ce tutorial sheet 10 09 2023 Tasks in gene1cs and gene regula1on. 1. What is the difference between a gene and a) An allele b) A cistron 2. Men9on 3 reasons why gene expression is regulated? 3. What is an operon? What kind of o...

January 2023 intake prac1ce tutorial sheet 10 09 2023 Tasks in gene1cs and gene regula1on. 1. What is the difference between a gene and a) An allele b) A cistron 2. Men9on 3 reasons why gene expression is regulated? 3. What is an operon? What kind of organisms use operons for gene regula9on? 4. List 5 components that are present in every operon. 5. What is the difference between the repression mechanism in the Lac operon and Trp operon of E.coli? 6. Differen9ate between the following pairs of terms: a) Chromosome and chroma9n b) Histone and nucleosome c) Heterochroma9n and euchroma9n d) Phenotype and genotype 7. Why is the promoter region of DNA rich in adenylate and thymidylate pairs (TATA box)? 8. What is the func9on of the regulatory gene in an operon? 9. What is the func9on of the operator region in the operon of prokaryotes? 10. Explain the role of acetyla9on and methyla9on in eukaryo9c gene regula9on. 11. What is the role of each of the following in eukaryo9c gene expression regula9on? a) micro RNAs b) small nuclear RNAs c) alterna9ve mRNA splicing 12. What is muta9on? Illustrate 4 types of muta9on in a cell. 13. What is a ‘silent muta9on’? 14. Explain the difference between an inducible gene and a house-keeping gene. 15. What is a carcinogen? Men9on 3 types. 16. Discuss the roles of the p53 gene in the cell. Why is p53 gene important in biochemistry of cancer? 17. What is carcinogenesis? List 4 mechanisms of carcinogenesis. 18. What is the meaning of X-linked recessive disorder? Why are X-linked recessive disorders commonly manifested in men and not in women? 19. A man who is a gene9c carrier for sickle cell disease mates with a woman who is a pa9ent of sickle cell disease. Sickle cell gene is carried on a recessive allele. Determine the % chance of this couple receiving a child who is phenotypically normal (not suffering from sickle cell disease). 20. What is the chance of having a child who is an albino if a man who is a normal homozygous dominant mates with a woman who is an albino. (Use A to represent the allele for normal skin color and a to represent a recessive allele for albinism).