Genetics help, please help. 1CA mutational event inserts one extra base pair int

Question

Genetics help, please help.

1CA mutational event inserts one extra base pair into DNA. Which of the following outcome do you expect? A no protein at all B protein in which only one amino acid is changed C protein in which three amino acids are changed D protein in which no amino acid is changed E protein in which most amino acids after the site of insertion are changed ) In any fragment of double-stranded DNA how many possible different reading frames are there? A 2 C 4 ) Nonsense suppressor mutations are the result of mutations in the amino acid binding site of tRNA wobble position of a codon A B C D E anti-codon of the rRNA stop codon of the rRNA none of the above Recombination in individuals heterozygous for a can produce chromosome containing two centromeres A Inversion B Translocation C Duplication D Deletion E. RFLP ) An E. coli strain possesses the following phenotype F(P')/ Ì P'O·Z'Y. where lis a mutation that eliminates production of the repressor and pe eliminates the ability of the polymerase to bind the promoter. The structural genes on the chromosome A will be transcribed in the presence and absence of lactose B will be transcribed only if lactose is present C will not be transcribed under any conditions

Explanation / Answer

If a mutation causes the insertion of one base anywhere in the middle of a DNA sequence, all the codons starting from the site of insertions will change, which will result in a protein that has most of the amino acids changed after the site of insertion. Therefore, your option is E is right. If the mutation is there at the first or last codon of the coding sequence then this insertion might result in a protein that has all its amino acids changed or a protein in which no amino acid is changed (option D) respectively. Similarly options B and C are applicable depending upon the site of insertion in the coding sequence. Therefore, B, C , D and E options are TRUE. There are 3 possible reading frames per strand of DNA, hence for a double- stranded DNA fragment the possible number of reading frames will be six. Therefore, your answer is E. A nonsense mutation occurs when a sense codon is changed to a chain?termination codon i.e. UAG, UAA or UGA. A nonsense suppressor mutation results from a second mutation affecting the translational apparatus. So all the options that include components of translational apparatus such as tRNA and rRNA are true. Mutation at wobble position is not considered a nonsense mutation; hence option B is not true. Therefore, your answers are A, C, and D We know that most dicentric chromosomes (chromosomes with two centromeres) are formed through chromosomal inversions, through irradiation or through shortening of telomeres with continued cell divison. These inversions are rotations in regions of a chromosome due to chromosomal breakages or intra-chromosomal recombination. Therefore, your answer is A.                                                        Thanks!

Related Questions

Navigate

• Browse (All)
• Browse G
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.