Question

Name (PRINT) 25. Codon degeneracy means There is a redundancy of the genetic code. Silent mutation is possible. c. Occurs at the third position of the genetic code. d. All of the above a. b 26. The F factor is passed from a F+ to a F- cell during: a. Binary fission. b. Standard double strand DNA replication. c. Homologous recombination. d. Rolling-circle replication. 27. The main difference between a F cell and a Hfr cell is that in Hfr cell: Genes on the chromosome can be transferred. F factor is in a plasmid. c. Most often the recipient F also becomes Hfr. d. After transfer, the Hfr losses its F factor and become F 28. During noncompetitive inhibition of enzyme activity, the Vmax cannot surpass the Vmax of enzyme activity without inhibitors because the active site in noncompetitive inhibitor: a. Does not compete directly with the substrate binding site. b. Has an allosteric regulation. C. Inhibits enzyme activity once the inhibitor binds to the enzyme. d All of the above, 29. Which is a palindromic sequence: 5'GGCCTAATGGCC3 b. 5'CGGCATATGCCG3 с. 5АTATTАТАТАТАТАЗ d. None of the above. a. 30. During cloning using the blue-white screen method, the vector that has the gene of interest inserted will yield white colony because: a. The gene of interest will degrade the X-gal and prevents the production of the blue color. b. The gene of interest will prevent production of the enzyme that utilizes X-gal therefore the colony remains white. c. The gene of interest will enhance the ampicillin resistance gene therefore allowing colony growth on the plate. d.) Both b and c. 31. Which sequence below will the probe that contains this sequence 5'GTATAATC3 hybridize to? a. 5'GTATAATC3' b. 5GTTATATС3 c. 5'GATTATAC3' d. 5'GAATTTAC3

Answer 1

25) the genetic code is degenerate means a single amino acid can be coded by more than one codon, that is genetic code is redundant, so if a mutation changes one codon say AUU to another codon say AUC then the amino acid is not changed that is both codons codes for isoleucine that is silent mutations are possible, AUA, AUU, AUC, codes for isoleucine that is the change occurs at the third base so the answer is d) all of the above.

26) F+ strain has the F plasmid and F- strain does not have F plasmid, F plasmid is passed through conjugation, the F plasmid replicates via rolling circle mechanism, that is a nick is made in one strand of the circular plasmid, then the one strand moves to the recipient strain, single-stranded DNA formed by the separation of DNA strands in the donor strain is replicated, as one strand moves so the answer is d) rolling circle replication.

27) in Hfr cell, the F plasmid can recombine with the genome so when the Hfr strain undergoes conjugation the genes from the genome can be transferred to the donor cell so the answers are a)genes on the chromosome can be transferred.c) most often the recipient F- also becomes Hfr.