Genetic Modification Flashcards
Genetically modified zebrafish, in a variety of bright colours, can be bought from some pet shops. The colour of the zebrafish depends on which gene has been added to its genome.
Suggest one potential risk to other organisms in a river ecosystem if a genetically modified zebrafish escaped into this river. (1)
[2014/01 WBI05/01]
The other zebrafish may get the genetically modified gene which would increase competition and reduce the population (1) of the original zebrafish without the genetically modified gene.
The transcription factor known as Sp2 has been studied. In this study, a gene from red coral cells was added to the genome of the zebrafish. The gene from red coral cells produces a red protein when the synthesis of Sp2 also occurs.
Suggest how this gene is removed from the red coral cells and then added to the zebrafish genome. (3)
[2014/01 WBI05/01]
Restriction enzyme (1) is used to cut out the Sp2 gene from the DNA (1) of red coral cells. The same restriction enzyme is used to cut open the DNA of the zebrafish (1). Ligase enzyme (1) is used to join the two DNA together and the gene becomes recombinant. The recombinant DNA is then placed into the zebrafish using a vector such as a micropipette injection (1).
The optimum temperature range for zebrafish to survive is 17–29°C.
An investigation was carried out to study the effect of water temperature on the survival of both genetically modified zebrafish and non-genetically modified zebrafish.
The results are shown in the table below.
(i) These results suggest that there would be less risk to the environment if zebrafish with the gene for the red protein escaped into a cold water river compared with non-genetically modified zebrafish.
Using the information in the table, give the evidence for this. (1)
(ii) These results also suggest that there may be no difference in the lowest temperature for survival of the zebrafish with the gene for the green protein and the non-genetically modified zebrafish.
Using the information in the table, give the evidence for this. (2)
[2014/01 WBI05/01]
(i) The fish with the gene for red protein is less likely to survive at lower temperatures (1).
(ii) There is a small difference between the mean (1) for the non-genetically modified zebrafish and the zebrafish with the gene for green protein. Additionally, their standard deviations have an overlap (1) which suggests that the results are not significant.
Pyrethrin is an insecticide produced naturally by chrysanthemum flowers found in East Africa.
Scientists have genetically modified yeast cells to produce pyrethrin.
Suggest how yeast cells could be genetically modified to produce pyrethrin. (4)
[2017/01 WBI05/01]
Gene for producing pyrethrin is taken from the chrysanthemum flowers (1) and are removed using restriction endonuclease (1). Using the same restriction endonuclease enzyme, a section of the plasmid (1) is cut. Using DNA ligase (1), it combines the gene with the plasmid to form a recombinant DNA. This recombinant DNA is placed into a bacterium, and it is injected into the yeast cell using a vector such as a gene gun or a micropipette injection. This introduces the gene to the yeast cell, which allows the yeast cell to have the gene to produce pyrethrin.
