A group of genes that are regulated together is called a(n)
promoter.
operon.
intron.
allele.
To turn on the lactose-digesting enzymes of E. coli, the lactose must first
bind to the repressor.
bind to the DNA of the bacterium.
separate from the repressor.
initiate the synthesis of messenger RNA.
Blocking gene expression in eukaryotes with microRNA strands is called RNA
transcription.
translation.
interference.
digestion.
How is gene expression controlled in prokaryotes?
What is meant by the term cell specialization? How is cell specialization controlled?
Describe how a TATA box helps position RNA polymerase in a eukaryotic cell.
What is a homeobox gene?
Think Critically
Apply Concepts The number of promoter sequences, enhancer sites, and the TATA box in eukaryotes makes gene regulation in these organisms far more complex than regulation in prokaryotes. Why is regulation in eukaryotes so much more sophisticated?
Connecting Concepts
Use Science Graphics
Use the data table to answer questions 35 and 36.
Relate Cause and Effect The table shows RNA codons for three amino acids. How would a substitution mutation in the third nucleotide position of the codons for alanine and valine affect the resulting protein?
Infer The three amino acids shown in the table have very similar—though not identical—properties. What substitution mutations could result in switching one of these amino acids for another? What might be the result?
Write About Science
Explanation Write a paragraph explaining why the effect of mutations can vary widely—from neutral to harmful to beneficial.
Assess the
Explain the roles of the three types of RNA in taking the information in DNA and using it to make proteins.
Analyzing Data
RNA is the genetic material of many viruses. Scientists analyzed RNA from four different types of viruses. The content of the four nitrogenous bases is shown below.
Interpret Graphics Which of the four types of viruses is most likely to use double-stranded RNA as its genetic material?
Virus A
Virus B
Virus C
Virus D
Infer The values in the two boxes labeled with an x would most likely be about
32.5% A and 32.5% U.
17.5% A and 17.5% U.
26.3% A and 29.3% U.
32.5% A and 17.5% U.
Table of Contents
- Formulas and Equations
- Applying Formulas and Equations
- Mean, Median, and Mode
- Estimation
- Using Measurements in Calculations
- Effects of Measurement Errors
- Accuracy
- Precision
- Comparing Accuracy and Precision
- Significant Figures
- Calculating With Significant Figures
- Scientific Notation
- Calculating With Scientific Notation
- Dimensional Analysis
- Applying Dimensional Analysis