21.1. Biotechnology and genetic modification
A subsection of Biology, 0610, through 21. Biotechnology and genetic modification
Listing 10 of 47 questions
Bacteria are used in many biotechnological processes. Explain why bacteria are useful in biotechnology. Insulin is one of many human proteins that are made by genetically engineered bacteria. Some people cannot produce insulin because their immune system has destroyed the cells that make insulin. State the organ that contains the cells that have been destroyed. State the name of the disease caused by the destruction of these cells. State the function of insulin in the body. Genetically engineered bacteria that are used to make insulin were grown in a fermenter for five days. Samples were taken from the fermenter every six hours and the number of bacteria in 1.0 mm3 of the nutrient solution were counted. Changes in the numbers of living bacteria in the samples taken from the fermenter are shown in . P Q R S Complete by adding labels for the axes at 1 and 2 . State the names of the stages of population growth of the bacteria labelled P to S. P Q R S Explain, with reference to , why the bacteria did not grow in the fermenter for longer than five days. Mineral salts are important in the human diet. One of the most important is iron. Explain: • the importance of iron in the human diet • the effects of an iron deficiency. shows a field of cassava, Manihot esculenta, which is a crop plant grown in parts of Africa and Asia. The plants store starch in their roots, which form a large part of the diet for many people. Cassava does not provide many vitamins or mineral ions. Genetic engineers have modified cassava to increase its iron content. They have done this by incorporating a gene for a membrane protein from the plant Arabidopsis thaliana. State the name of the enzyme that is used to cut out the gene from the DNA of A. thaliana. Describe how the gene from A. thaliana and the DNA from cassava form recombinant DNA. Scientists who develop genetically engineered varieties of crop plants often breed them for several generations before releasing them for farmers to use. Suggest why the scientists do this.
0610_s21_qp_41
THEORY
2021
Paper 4, Variant 1
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shows some of the stages in the reproduction of the bacterium Escherichia coli. loop of DNA original bacterial cell bacterial cell expands to a critical length and a copy of DNA is synthesised daughter cells are formed daughter cells grow Complete the sentences about the cells in . The DNA is in the form of a double . The DNA is copied so that the number of loops of DNA after cell division is in each daughter cell. The daughter cells are genetically to the original cell. Students used a microscope and time-lapse photography to observe E. coli cells reproducing. They used the series of photographs to identify which cells were dividing. They measured the lengths of the dividing cells and put their data into two groups: • cell lengths immediately before cell division • cell lengths immediately after cell division. shows their results. number of cells cell length / μm immediately after division key: immediately before division Use the information in to state the most frequent cell length of the E. coli cells immediately after cell division. Give your answer in millimetres. mm Some students concluded that the cells must be at least 6 µm in length before cell division can occur. Describe the evidence against the students’ conclusion. Use the information in to support your answer. Bacteria are useful in genetic engineering because they contain plasmids. Describe how a plasmid is cut so that a new gene can be inserted into the plasmid. List two reasons, other than the presence of plasmids, that make bacteria and single-celled fungi useful to biotechnology industries.
0610_s21_qp_42
THEORY
2021
Paper 4, Variant 2
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Questions Discovered
47