Gene Expression Student: 1. A ribozyme is A. a section of the DNA that is expressed in the mrna. B. a self-splicing intron that acts like an enzyme. C. a complex made up of many ribosomes replicating the same strand of mrna. D. one of the small ribosomal subunits. E. the enzyme that attaches amino acids to trna. 2. Which of the following nucleotide bases is found only in DNA, not in RNA? A. guanine B. adenine C. thymine D. uracil E. cytosine 3. Which of the following nucleotide bases is found only in RNA, not in DNA? A. guanine B. adenine C. thymine D. uracil E. cytosine 4. If one strand of DNA has the base sequence AAGCAA, the complementary strand has which of the following sequences? A. UUCGUU B. TTCGTT C. AAGCAA D. UTCGTU E. TTCGTG Page 1
5. Transcription of a part of a DNA molecule with a nucleotide sequence of A-A-A-C-A-A-C-T-T results in a mrna molecule with the complementary sequence of A. G-G-G-A-G-A-A-C-C. B. U-U-U-G-U-U-G-A-A. C. T-T-T-G-A-A-G-C-C. D. C-C-C-A-C-C-T-C-C. E. none of the choices are correct. 6. Prior to protein synthesis, the DNA A. attracts trnas with appropriate amino acids. B. must first undergo replication. C. contains anticodons that must become codons. D. serves as a template for the production of mrna. E. adheres to ribosomes for protein synthesis. 7. Which of the classes of RNA molecules carries the genetic information as it is needed for the construction of a protein? A. ribosomal RNA B. transfer RNA C. messenger RNA D. primary mrna transcript 8. On a hypothetical planet, life evolves based on a DNA-like molecule with six rather than four nucleotides. Which table reflects the number of bases for each number of codons and the corresponding number of combinations of different amino acids that could be specified? A. A B. B C. C D. D Page 2
9. Today, it is most appropriate to state that a gene controls A. one enzyme. B. one protein. C. one polypeptide chain. D. one amino acid. E. one starch, amino acid or lipid molecule. 10. Gene expression is controlled at which level(s)? A. Rate of mrna synthesis (the rate of transcription) B. mrna processing and stability C. Rate of protein synthesis (the rate of translation) D. Protein stability E. All of the above steps 11. Gene expression is MAINLY controlled at which level(s)? A. Rate of mrna synthesis (the rate of transcription) B. mrna processing and stability C. Rate of protein synthesis (the rate of translation) D. Protein stability E. All of the above steps 12. Which of the following would be transcribed into a piece of mrna? A. a noncoding gene B. a protein-coding gene C. a promoter D. a ribozyme 13. Which of the following is/are true concerning introns? A. Introns are sections of nucleotides found on a mrna transcript. B. RNA splicing usually removes introns from a mrna molecule. C. Introns can function to regulate gene expression. D. The sequence of nucleotides found in introns are not known to represent anything usable by the cell. E. All the choices are true except for saying that introns do not represent anything usable by the cell. Page 3
Gene Expression Key 1. A ribozyme is a. a section of the DNA that is expressed in the mrna. B. a self-splicing intron that acts like an enzyme. c. a complex made up of many ribosomes replicating the same strand of mrna. d. one of the small ribosomal subunits. e. the enzyme that attaches amino acids to trna. 2. Which of the following nucleotide bases is found only in DNA, not in RNA? a. guanine b. adenine C. thymine d. uracil e. cytosine 3. Which of the following nucleotide bases is found only in RNA, not in DNA? a. guanine b. adenine c. thymine D. uracil e. cytosine 4. If one strand of DNA has the base sequence AAGCAA, the complementary strand has which of the following sequences? a. UUCGUU B. TTCGTT c. AAGCAA d. UTCGTU e. TTCGTG Page 1
5. Transcription of a part of a DNA molecule with a nucleotide sequence of A-A-A-C-A-A-C-T-T results in a mrna molecule with the complementary sequence of a. G-G-G-A-G-A-A-C-C. B. U-U-U-G-U-U-G-A-A. c. T-T-T-G-A-A-G-C-C. d. C-C-C-A-C-C-T-C-C. e. none of the choices are correct. 6. Prior to protein synthesis, the DNA a. attracts trnas with appropriate amino acids. b. must first undergo replication. c. contains anticodons that must become codons. D. serves as a template for the production of mrna. e. adheres to ribosomes for protein synthesis. 7. Which of the classes of RNA molecules carries the genetic information as it is needed for the construction of a protein? a. ribosomal RNA b. transfer RNA C. messenger RNA d. primary mrna transcript 8. On a hypothetical planet, life evolves based on a DNA-like molecule with six rather than four nucleotides. Which table reflects the number of bases for each number of codons and the corresponding number of combinations of different amino acids that could be specified? a. A b. B c. C D. D Page 2
9. Today, it is most appropriate to state that a gene controls a. one enzyme. b. one protein. C. one polypeptide chain. d. one amino acid. e. one starch, amino acid or lipid molecule. 10. Gene expression is controlled at which level(s)? a. Rate of mrna synthesis (the rate of transcription) b. mrna processing and stability c. Rate of protein synthesis (the rate of translation) d. Protein stability E. All of the above steps 11. Gene expression is MAINLY controlled at which level(s)? A. Rate of mrna synthesis (the rate of transcription) b. mrna processing and stability c. Rate of protein synthesis (the rate of translation) d. Protein stability e. All of the above steps 12. Which of the following would be transcribed into a piece of mrna? a. a noncoding gene B. a protein-coding gene c. a promoter d. a ribozyme 13. Which of the following is/are true concerning introns? a. Introns are sections of nucleotides found on a mrna transcript. b. RNA splicing usually removes introns from a mrna molecule. c. Introns can function to regulate gene expression. d. The sequence of nucleotides found in introns are not known to represent anything usable by the cell. E. All the choices are true except for saying that introns do not represent anything usable by the cell. Page 3