3.5 – Genetic Modification and Biotechnology

1.HindIII is an endonuclease that recognizes the sequence A A G C T T, cutting between the two adenines. Into how many DNA fragments would the strand shown be cut by HindIII?

2. Cladograms can be created by comparing DNA or protein sequences. The cladogram on the left is based on DNA sequences and the cladogram on the right is based on comparing protein sequences. What is the reason that cladograms based on DNA sequences are more reliable predictors of the phylogenetic relationship of species than cladograms based on protein sequences?

3. The bacterium Neisseria gonorrhoeae causes infections related to the human reproductive system. The graph shows the percentage of samples in which this bacterium showed resistance to six antibiotics over a period of ten years. What is a possible explanation for the total percentage resistance being larger than 100% in 2010?

4. A DNA profile was made of one individual in a paternity suit. Locus B was used to distinguish between this individual and other individuals. The individual had two alleles of the gene at locus B which are shown below: Gel electrophoresis was used to separate and visualize the alleles B3 and B5. The gel, with two bands of DNA, is shown below. What DNA is in bands 1 and 2?

5. Which is a possible risk associated with a genetic modification of crops?  

6. What is produced by somatic-cell nuclear transfer?

7. Which technique separates proteins according to size?  

8. Which sequence of DNA would be suitable in DNA profiling?

9. A colour blind man and a woman carrier for colour blindness have a son. What is the probability that their son will be colour blind?

10. Laboratory analysis of DNA from a 40 000 year old woolly mammoth used the polymerase chain reaction (PCR). What role did the PCR have in the analysis?  

11. How are enzymes used during gene transfer involving plasmids?

12. What was an aim of genetic modification of organisms?

13. Which process can be used to amplify small fragments of DNA?

14. What is a definition of a clone?

15. What was an aim of genetic modification of organisms?

16. What happens to DNA fragments in electrophoresis?

17. The flow chart summarizes methods of gene transfer. Which enzymes are used in steps I and II?

18. The diagram shows results of electrophoresis of DNA from a crime scene. Which suspect could be implicated as the criminal, according to the gel of DNA shown?

19. When genes are transferred between species, the amino acid sequence of the polypeptide translated from them is unchanged. Why is this so?

20. What makes gene transfer between species possible?

21. What is amplified using the polymerase chain reaction (PCR)?

22. What is a plasmid?

23. What makes gene transfer between species possible?

24. What is a plasmid?

25. Which technique causes fragments of DNA to move in an electric field?

26. Which of the following types of information are needed to construct a karyotype? I.   Size of the chromosomes II.  Gene mutations of the chromosomes III. Age of the individual

27. Which enzymes are needed to produce recombinant plasmids to be used in gene transfer?

28. How is the polymerase chain reaction (PCR) used?

29. Rhesus factor is an antigen present on the surface of red blood cells of Rhesus positive individuals. Rhesus positive (Rh+ ) is dominant to Rhesus negative (Rh– ). A mother with Rhesus negative blood gives birth to a baby with Rhesus positive blood and there are concerns that subsequent pregnancies will trigger an immune response. What is a possible explanation for why subsequent pregnancies could trigger an immune response?

30. A new allele that provides herbicide resistance is identified in soybean plants. The allele is dominant. Which of the following would be carried out in a herbicide-resistant plant to find out if it is homozygous or heterozygous for the gene?

31. Which statement about the polymerase chain reaction (PCR) is correct?

32. Which processes involved in cloning an animal are indicated by the letters X and Y?

33. The diagram below represents the results obtained in a DNA profile from a crime scene. Suspect 2 is most likely to be the criminal because the band pattern coincides with that of the crime scene sample. What do these bands represent?

34. What does the universal nature of the genetic code allow?

35. A small amount of a suspect’s DNA is obtained from a crime scene. What techniques would be used to carry out DNA profiling?

36. What type of enzyme could be used to cut a DNA molecule as indicated by the dotted line on the diagram below?

37. What does therapeutic cloning involve?

38. Which process is used in polymerase chain reaction (PCR)?

39. What conclusion can be made from the following evidence from an analysis of DNA fragments?

40. What could be achieved by DNA profiling using gel electrophoresis?