A scientist inserts a radioactively labeled DNA molecule into a bacterium. The bacterium

A molecule of DNA contains two polymer strands called __________, made by bonding together many monomers called __________.

Name the three parts of every nucleotide.

Which of the following correctly ranks nucleic acid structures in order of size, from largest to smallest? a. gene, chromosome, nucleotide, codon b. chromosome, gene, codon, nucleotide c. nucleotide, chromosome, gene, codon d. chromosome, nucleotide, gene, codon

A scientist inserts a radioactively labeled DNA molecule into a bacterium. The bacterium replicates this DNA molecule and distributes one daughter molecule (double helix) to each of two daughter cells. How much radioactivity will the DNA in each of the two daughter cells contain? Why?

The nucleotide sequence of a DNA codon is GTA. What would be the nucleotide sequence of an mRNA molecule transcribed from this DNA? In the process of protein synthesis, a tRNA pairs with the mRNA codon. What is the nucleotide sequence of the tRNA anticodon that corresponds to this mRNA codon? What amino acid is attached to the tRNA (see Figure 10.10)?

Describe the process by which the information in a gene is transcribed and translated into a protein. Correctly use these terms in your description: tRNA, amino acid, start codon, transcription, mRNA, gene, codon, RNA polymerase, ribosome, translation, anticodon, peptide bond, stop codon.

Match the following molecules with the cellular process or processes in which they are primarily involved. a. ribosomes b. tRNA c. DNA polymerases d. RNA polymerase e. mR 1. DNA replication 2. transcription 3. translation

A geneticist finds that a particular mutation has no effect on the polypeptide encoded by the gene. This mutation probably involves a. deletion of one nucleotide. b. alteration of the start codon. c. insertion of one nucleotide. d. substitution of one nucleotide

Scientists have discovered how to put together a bacteriophage with the protein coat of phage A and the DNA of phage B. If this composite phage were allowed to infect a bacterium, the phages produced in the cell would have a. the protein of A and the DNA of B. b. the protein of B and the DNA of A. c. the protein and DNA of A. d. the protein and DNA of B.

How do some viruses reproduce without ever having DNA?

HIV requires an enzyme called ______________ to convert its RNA genome to a DNA version. Why is this enzyme a particularly good target for anti-AIDS drugs? (Hint: Would you expect such a drug to harm the human host?)

A cell containing a single chromosome is placed in a medium containing radioactive phosphate, making any new DNA strands formed by DNA replication radioactive. The cell replicates its DNA and divides. Then the daughter cells (still in the radioactive medium) replicate their DNA and divide, resulting in a total of four cells. Sketch the DNA molecules in all four cells, showing a normal (nonradioactive) DNA strand as a solid line and a radioactive DNA strand as a dashed line.

In a classic 1952 experiment, biologists Alfred Hershey and Martha Chase labeled two batches of bacteriophages, one with radioactive sulfur (which only tags protein) and the other with radioactive phosphorus (which only tags DNA). In separate test tubes, they allowed each batch of phages to bind to nonradioactive bacteria and inject its DNA. After a few minutes, they separated the bacterial cells from the viral parts that remained outside the bacterial cells and measured the radioactivity of both portions. What results do you think they obtained? How would these results help them to determine which viral componentDNA or proteinwas the infectious portion?

Interpreting Data The graph below summarizes the number of children who died of all strains of flu from 2007 until 2013. Each bar represents the number of child deaths occurring in one week. Why does the graph have the shape it does, with a series of peaks and valleys? Looking over the Biology and Society section at the start of the chapter, why does the graph reach its highest points near the middle? Based on these data, when does flu season begin and end in a typical year?

Scientists at the National Institutes of Health (NIH) have worked out thousands of sequences of genes and the proteins they encode, and similar analyses are being carried out at universities and private companies. Knowledge of the nucleotide sequences of genes might be used to treat genetic defects or produce lifesaving medicines. NIH and some U.S. biotechnology companies have applied for patents on their discoveries. In Britain, the courts have ruled that a naturally occurring gene cannot be patented. Do you think individuals and companies should be able to patent genes and gene products? Before answering, consider the following: What are the purposes of a patent? How might the discoverer of a gene benefit from a patent? How might the public benefit? What negative effects might result from patenting genes?

Your college roommate seeks to improve her appearance by visiting a tanning salon. How would you explain the dangers of this to her?

Flu vaccines have been shown to be safe, are very reliable at reducing the risk of hospitalization or death from influenza, and are inexpensive. Should children be required to obtain a flu vaccine before going to school? What about hospital workers before reporting to work? Defend your answers to these questions.