On-line quiz 6 on Ch 14 (Translation) and Ch 15 (Mutation)Q.1 The term peptidyl transferase relates to ________.a. Base additions during mRNA synthesis*b. Peptide bond formation during protein synthesis.c. Elongation factors binding to the large ribosomal subunitd. Discontinuous strand replicationQ.2 All t-RNAs have CCA sequence at their: a. Anticodon loop.b. 5’-end.*c. 3’-end.d. 5’- and 3’-ends.Q.3 Which of the following bases will pair with inosine?a. Guanine or thymine.b. Adenine or guanine or thymine.c. Cytosine.*d. Adenine, uracil or cytosine.Q.4 A tRNA is called a charged tRNA when it is:a. Electrically charged.*b. Attached to its specific amino acid.c. Moved to the E site of the ribosome.d. Attached to its aminoacyl tRNA synthetase.Q.5 Which of the following tRNAs is attached to the nascent polypeptide chain during translation?tRNA at the ___________a. A site.b. E site.c. Both P and A sites.*d. P site.Q.6 Which of the following statements is true? During translation__________*a. mRNA is read starting at its 5’- end.b. New polypeptide chain grows towards N’ terminal end.c. In eukaryotes, the AUG codon codes for N-formylmethionine.d. Final products of all genes are polypeptides.Q.7 Which of the following steps is dependent on Shine-Dalgarno sequence?a. Termination of translation.b. Initiation of transcription.*c. Binding of the small ribosome to 5’-end of bacterial mRNA.d. Anticodon-codon bonding. Q.8 Which of the following factors brings charged tRNA to the A site of the ribosome?a. EF-G.b. EF-Ts.*c. EF-Tu.d. IF2Q.9 The translation initiation complex in bacteria contains___________*a. Small ribosome, mRNA and initiator tRNA.b. Large ribosome, mRNA and initiator tRNA.c. IF2, GTP and initiator tRNA.d. Small ribosome, mRNA and amino acid.Q.10 A point mutation may:a. Delete a base.b. Add a base.c. Cause a frame-shift mutation.*d. All of the above.Q.11 If a point mutation does not change the amino acid, it is classified as:a. Non-sense mutation.*b. Silent mutation.c. Transition mutation.d. Missense mutation.Q.12 In case of transition mutation, (this question is wrongly worded. No answer choice is correct)a. Purine changes to pyrimidine.b. Pyrimidine changes to purine.c. Purine changes to pyrimidine and vice versa.d. Two thymines next to each other dimerize.Q.13 The amino form of adenine can pair witha. Keto form of thymine.b. Imino form of cytosine.*c. Both a and b are correct.d. Amino form of cytosine.Q.14 The MutH protein:*a. Cuts DNA not methylated at the adenine of GATC sequence.b. Cuts DNA methylated at the adenine of GATC sequence.c. Cuts DNA in a DNA:RNA hybrid.d. Is an eukaryotic protein.Q.15 Which of the following statements is true?a. The Ac element has a mutation in the transposase gene.b. The Ds element can move because it produces transposase.*c. Without Ac element the Ds element cannot move.d. Ds and Ac elements help each other to move.Q.16 Suppose, mitosis takes place in a cell with genotype T/t ; Y/y. The genotype expected in the daughter cells isa. T ; Yb. T/tc. Y/y*d. T/t; Y/yQ.17 An insect has three pairs of homologous chromosomes: A1A2, B1B2 and C1C2. How many different types of gametes (chromosomal combinations) is expected to be produced by this insect? a. Two.b. Six.*c. Eight.d. Twelve.Q.18 At anaphase Ia. Sister chromatids segregate to the opposite poles.*b Sister chromatids segregate to the same pole.c. Homologous chromosomes pair.d. All four chromatids of a tetrad randomly segregate into the daughter cells.Q.19 Albinism, lack of pigmentation in humans, results from an autosomal recessive gene. If two parents with normal pigmentation have an albino child, what is the probability that their nextchild will be an albino boy?a. 1/4b. 1/2c. 1/6*d. 1/8Q.20 Hyperchromic shift of DNA at 950C is observed at 260 nm UV because,a. The sugars become exposed.b. The phosphates become exposed.*c. The bases become exposed.d. DNA degrades into
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