OpenStax Biology 2e Instructor Answer Guide
Biology 2e
Unit 3: Genetics
Chapter 15: Genes and Proteins
Visual Connection Questions
1. A scientist splices a eukaryotic promoter in front of a bacterial gene and inserts the gene in a
bacterial chromosome. Would you expect the bacteria to transcribe the gene?
No. Prokaryotes use different promoters than eukaryotes.
2. Errors in splicing are implicated in cancers and other human diseases. What kinds of
mutations might lead to splicing errors? Think of different possible outcomes if splicing errors
occur.
Mutations in the spliceosome recognition sequence at each end of the intron, or in the proteins
and RNAs that make up the spliceosome, may impair splicing. Mutations may also add new
spliceosome recognition sites. Splicing errors could lead to introns being retained in spliced
RNA, exons being excised, or changes in the location of the splice site.
, OpenStax Biology 2e Instructor Answer Guide
3. Many antibiotics inhibit bacterial protein synthesis. For example, tetracycline blocks the A
site on the bacterial ribosome, and chloramphenicol blocks peptidyl transfer. What specific
effect would you expect each of these antibiotics to have on protein synthesis?
Tetracycline: a. tRNA binding to the ribosome; Chloramphenicol: c. growth of the protein chain
Review Questions
4. The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic code
explains this?
d. degeneracy
5. How many nucleotides are in 12 mRNA codons?
c. 36
6. Which event contradicts the central dogma of molecular biology?
c. Scientists use reverse transcriptase enzymes to make DNA from RNA.
7. Which subunit of the E. coli polymerase confers specificity to transcription?
d. σ
8. The -10 and -35 regions of prokaryotic promoters are called consensus sequences because
________.
b. they are similar in all bacterial species
Biology 2e
Unit 3: Genetics
Chapter 15: Genes and Proteins
Visual Connection Questions
1. A scientist splices a eukaryotic promoter in front of a bacterial gene and inserts the gene in a
bacterial chromosome. Would you expect the bacteria to transcribe the gene?
No. Prokaryotes use different promoters than eukaryotes.
2. Errors in splicing are implicated in cancers and other human diseases. What kinds of
mutations might lead to splicing errors? Think of different possible outcomes if splicing errors
occur.
Mutations in the spliceosome recognition sequence at each end of the intron, or in the proteins
and RNAs that make up the spliceosome, may impair splicing. Mutations may also add new
spliceosome recognition sites. Splicing errors could lead to introns being retained in spliced
RNA, exons being excised, or changes in the location of the splice site.
, OpenStax Biology 2e Instructor Answer Guide
3. Many antibiotics inhibit bacterial protein synthesis. For example, tetracycline blocks the A
site on the bacterial ribosome, and chloramphenicol blocks peptidyl transfer. What specific
effect would you expect each of these antibiotics to have on protein synthesis?
Tetracycline: a. tRNA binding to the ribosome; Chloramphenicol: c. growth of the protein chain
Review Questions
4. The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic code
explains this?
d. degeneracy
5. How many nucleotides are in 12 mRNA codons?
c. 36
6. Which event contradicts the central dogma of molecular biology?
c. Scientists use reverse transcriptase enzymes to make DNA from RNA.
7. Which subunit of the E. coli polymerase confers specificity to transcription?
d. σ
8. The -10 and -35 regions of prokaryotic promoters are called consensus sequences because
________.
b. they are similar in all bacterial species
