This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Biology Chapter 6 Molecular Basis Of Inheritance – Quiz 34 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 34 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The regulator gene of a bacterial operon A) Codes for inducer substances. B) Codes for repressor proteins. C) Acts as an on-off switch for the structural genes. D) Is a binding site for RNA polymerase. Show Answer Correct Answer: B) Codes for repressor proteins. 2. Which of the following region(s) does not code for any proteins?(i) Introns(ii) Exons(iii) VNTRs A) Only i and iii. B) Only ii and iii. C) Only i. D) All i, ii and iii. Show Answer Correct Answer: A) Only i and iii. 3. What non-radioactive isotope was used by Meselson and Stahl to label DNA in their experiment? A) 35S. B) N15. C) P21. D) None. Show Answer Correct Answer: B) N15. 4. After the first replication was observed in their experiments testing the nature of DNA replication, Meselson and Stahl could be confident of which of the following conclusions? A) Replication is neither dispersive nor conservative. B) Replication is semi-conservative. C) Replication is not conservative. D) Replication is not dispersive. Show Answer Correct Answer: C) Replication is not conservative. 5. Direction that DNA is READ? A) 3' to 5'. B) 5' to 3'. C) All the above. D) None of the above. Show Answer Correct Answer: A) 3' to 5'. 6. During Griffith's experiments with Streptococcus pneumoniae in mice, material from ..... bacteria transformed ..... bacteria. A) Living nonpathogenic living pathogenic. B) Living pathogenic heat-killed nonpathogenic. C) Heat-killed pathogenic living nonpathogenic. D) Heat-killed nonpathogenic living pathogenic. Show Answer Correct Answer: C) Heat-killed pathogenic living nonpathogenic. 7. Minisatellite are A) 10-40bp sized short sequences within the genes. B) Short coding repetitive regions on the eukaryotic genome. C) Short non-coding repetitive sequences present throughout the chromosomes. D) Regions of chromosomes at centromere. Show Answer Correct Answer: C) Short non-coding repetitive sequences present throughout the chromosomes. 8. Which enzyme proofreads and removes RNA Primase A) Ligase. B) Polymerase 1. C) Polymerase 3. D) HelicaseTagsDNA replication enzymes. Show Answer Correct Answer: B) Polymerase 1. 9. Elect the two correct statements out of the four (l-IV) given below about Lac operon. I. Glucose or galactose may bind with the repressor and inactivate it. II. in the absence of lactose the repressor binds with the operator region III. The z-gene codes for regionIV. This was elucidated by Francois Jacob and Jacques Monad The correct statement are: A) I and II. B) II and IV. C) I and III. D) II and III. Show Answer Correct Answer: B) II and IV. 10. The following is not a character of RNA: A) RNA is unstable and degradable. B) RNA mutates at faster rate than DNA. C) RNA evolves slowly. D) RNA is catalytic /reactive. Show Answer Correct Answer: C) RNA evolves slowly. 11. If the mechanism of DNA replication in this bacterium were dispersive, what results would be found when the double-stranded DNA was analyzed in a CsCl gradient after two generations in 15N-medium? A) One band would be observed containing all the DNA. B) Two bands would be observed containing equal amounts of DNA. C) Two bands would be observed containing unequal amounts of DNA. D) The DNA cannot form any bands if replication is dispersive. Show Answer Correct Answer: A) One band would be observed containing all the DNA. 12. The capping of nucleotide prevents the rapid cleavage of mRNA and catalyzed by guanylyltransferase. Identify the nucleotide cap that is attached at the 5'end of mRNA. A) 5-methyl guanosine. B) 7-methyl guanosine. C) 5-acetyl guanosine. D) 7-acetyl guanosine. Show Answer Correct Answer: B) 7-methyl guanosine. 13. The genetic code of proline are: A) CCC CCG CCU. B) CUU UCA CUG. C) GUU GUC GUG. D) GGU GUC GGA. Show Answer Correct Answer: A) CCC CCG CCU. 14. Assertion:Adenine cannot pair with cytosine.Reason:Adenine and Cytosine do not have a perfect match between hydrogen donor and hydrogen acceptor sites. Hence they cannot pair.A-If both A and R are true and R is the correct explanation of A.B-If both A and R are true but R is not the correct explanation of A. C-If A is true but R is false. D-If both A and R are false. A) A. B) B. C) C. D) D. Show Answer Correct Answer: A) A. 15. Which of the following will form a palindromic sequence? A) GTTGGAAC. B) GTTCCAAG. C) AGTCCTGA. D) ATTGCAAT. Show Answer Correct Answer: D) ATTGCAAT. 16. The most abundant RNA is A) MRNA. B) TRNA. C) RRNA. D) SnRNA. Show Answer Correct Answer: C) RRNA. 17. In DNA replication each newly made strand is A) Identified in DNA sequence to the strand from which it was copied. B) Complementary in sequence to the strand from which it was copied. C) Oriented in the same 3' to 5' direction as the strand from which it was copied. D) An incomplete copy of one of the parental strands. Show Answer Correct Answer: B) Complementary in sequence to the strand from which it was copied. 18. To show that DNA in cell extracts was responsible for genetic transformation in Pneumococcus, important corroborating evidence was that A) Enzymes that destroyed proteins also destroyed transforming activity. B) Enzymes that destroyed DNA also destroyed transforming activity. C) Enzymes that destroyed polysaccharides also destroyed transforming activity. D) Boiling destroyed transforming activity. Show Answer Correct Answer: B) Enzymes that destroyed DNA also destroyed transforming activity. 19. In E. coli, the lac operon gets switched on when: A) Lactose is present and it binds to the repressor. B) Repressor binds to operator. C) RNA polymerase binds to the operator. D) Lactose is present and it binds to RNA polymerase. Show Answer Correct Answer: A) Lactose is present and it binds to the repressor. 20. If there are 999 bases in an RNA that codes for a protein with 333 amino acids, and the base at position 901 is deleted such that the length of the RNA becomes 998 bases, how many codons will be altered? A) 11. B) 33. C) 333. D) 1. Show Answer Correct Answer: B) 33. 21. Transcription occurs along a ..... template forming an mRNA in the ..... direction A) 5' to 3'; 5' to 3'. B) 5' to 3'; 3' to 5'. C) 3' to 5'; 5' to 3'. D) 3' to 5'; 3' to 5'. Show Answer Correct Answer: C) 3' to 5'; 5' to 3'. 22. Which of the following is not a part of a nucleoside? A) Deoxyribose sugar. B) Base. C) Glycosidic linkage. D) Phosphate. Show Answer Correct Answer: D) Phosphate. 23. The length of DNA molecule greatly exceeds the dimensions of the nucleus in eukaryotic cells. How is this DNA accommodated? A) Deletion of non-essential genes. B) Super-coiling in nucleosomes. C) DNAse digestion. D) Through elimination of repetitive DNA. Show Answer Correct Answer: B) Super-coiling in nucleosomes. 24. The total number of genes in human genome is approximately: A) 1, 00, 000. B) 50, 000. C) 20, 000-25, 000. D) 5, 000. Show Answer Correct Answer: C) 20, 000-25, 000. 25. At each end of a DNA replication bubble is ..... A) A replication fork. B) A ribosome. C) An origin of replication. D) A gene. Show Answer Correct Answer: A) A replication fork. ← PreviousNext →Related QuizzesClass 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 1Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 2Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 3Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 4Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 5Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 6Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 7Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 8Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 9Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books