Identify the best match between the mutation description and term.

Question 2. From mouse nerve cells you isolate the mouse Tau-gene-containing DNA fragment and hybridize it to the mRNA encoding Tau from the cytoplasm of the same cells. Describe what you see when you look at the molecules under the electron microscope. A. A double-stranded DNA-RNA hybrid with complete overlap of all the sequences. B. A partially double stranded DNA-RNA hybrid molecule containing regions of DNA-RNA overlap representing the mRNA exons, loops where there are introns and tails at the 5' and 3' ends. C. A partially double-stranded molecule containing regions of DNA-RNA overlap representing the mRNA introns, loops where there are introns and tails at the 5' and 3' ends. D. Regions of DNA-RNA overlap representing the mRNA exons and loops where there are introns with no tails at the 5' or 3' ends. E. Two distinct molecules with no overlapping regions. Multiple Choice

QUESTION 19 Place the following steps in the expression of the lac operon in the order in which each occurs for the first time after a cell is induced. v A phosphodiester bond is formed between two ribonucleotides. - A peptide bond is formed between the first two amino acids in beta-galactosidase (lac Z). Sigma protein binds to a specific DNA sequence. RNA polymerase ends transcription of the lacA gene. v A protein leaves an operator DNA sequence. v A ribosomal RNA binds to a complementary sequence in mRNA.

Question 20 : The restriction map of the plasmid pSC48 is presented below. The numbers in parentheses correspond to the position of the respective restriction site with respect to position (0). (0) BamHI ЕcoRI (4640) (620) PSC48 5200 pb BamHI (1130) Smal ЕcoRI (3420) (1350) The plasmid has been digested by one or several restriction enzyme(s). The digestion products have been analysed by agarose gel electrophorese. (see figure below). 1 2 10,000 8,000 6,000 5,000 4,000 3,000 2,500 –2,000 - 1,500 -1,000 -750 - 500 -250 1. Digestion products 2. Size marker base pairs Which restrcition enzyme(s) have been used for the digestion? (Indicate the right answer) А- ЕсoRI. B- EcoRI/BamHI. C- EcoRI/Smal. D- BamHI. E- Smal. | |

Question 47 (a) Use the following figure to determine the changes to the amino acids that correspond to the normal and mutated DNA sequences. Normal DNA sequence: 3 CAT TCA AAC ATT 5 Mutated DNA sequence: 3 CAT AGT GAG GTC 5 (Hint: Write the mRNA first, then identify the amino acids.) (b) What type of mutation is shown? First base of codon U C A G U UUU UUC UUA UUG CUU CUC CUA CUG AUU AUC AUA AUG GUU GUC GUA GUG UCU UCC UCA UCG CCU CCC CCA CCG ACU ACC ACA Met ACG GCU GCC GCA GCG Phe -Leu Leu lle Second base of codon A C Val -Ser Pro Thr Ala UAUTYT туг UAC UAA UAG CAU CAC CAA CAG. His Gin AAU AAC Asn AAA GAUT GAC GAA GAG Asp G AAGLYS AGG. GGU GGC GGA GGG Glu UGU UGC UGA UGG CGU CGC CGA CGG Bys A Trp G U C -Arg AGU AGC AGA аса за Ser Arg U C Gly AG A U C A G U C A G Third base of codon

QUESTION 15 TRNA: a. can be drawn as a cloverleaf structure b. Has an anticodon C. has modified bases d. all of the above