Interpreting Data When comparing genomes from different species, biologists often

Suppose you wish to create a large batch of the protein lactase using recombinant DNA. Place the following steps in the order you would have to perform them. a. Find the clone with the gene for lactase. b. Insert the plasmids into bacteria and grow the bacteria into clones. c. Isolate the gene for lactase. d. Create recombinant plasmids, including one that carries the gene for lactase.

A carrier that moves DNA from one cell to another, such as a plasmid, is called a __________.

In making recombinant DNA, what is the benefit of using a restriction enzyme that cuts DNA in a staggered fashion?

A paleontologist has recovered a bit of organic material from the 400-year-old preserved skin of an extinct dodo. She would like to compare DNA from the sample with DNA from living birds. The most useful method for initially increasing the amount of dodo DNA available for testing is __________.

Why do DNA fragments containing STR sites from different people tend to migrate to different locations during gel electrophoresis?

What feature of a DNA fragment causes it to move through a gel during electrophoresis? a. the electrical charges of its phosphate groups b. its nucleotide sequence c. the hydrogen bonds between its base pairs d. its double helix shape

After a gel electrophoresis procedure is run, the pattern of bars in the gel shows a. the order of bases in a particular gene. b. the presence of various-sized fragments of DNA. c. the order of genes along particular chromosomes. d. the exact location of a specific gene in the genome.

Name the steps of the whole-genome shotgun method.

Put the following steps of human gene therapy in the correct order. a. Virus is injected into patient. b. Human gene is inserted into a virus. c. Normal human gene is isolated and cloned. d. Normal human gene is transcribed and translated in the patient.

Some scientists once joked that when the DNA sequence of the human genome was complete, we can all go home because there would be nothing left for genetic researchers to discover. Why havent they all gone home?

Interpreting Data When comparing genomes from different species, biologists often calculate the genome density, the number of genes per number of nucleotides in the genome. Refer to Table 12.1. You can calculate the gene density of each species by dividing the number of genes by the size of the genome (usually expressed in Mb, which is mega base pairs, or 1 million base pairs). Using a spreadsheet, calculate the gene density for every species in the table. (Dont forget that 1 billion = 1,000 million; for example, humans have 3,000 Mb.) How does the gene density of bacteria compare to humans? Humans and roundworms have nearly the same number of genes, but how do the gene densities of these two species compare? Can you identify any general correlation between gene density and the size or complexity of an organism?

Listed below are 4 of the 13 genome sites used to create a standard DNA profile. Each site consists of a number of short tandem repeats: sets of 4 nucleotides repeated in a row within the genome. For each site, the number of repeats found at that site for this individual are listed: Chromosome number Genetic site # of repeats 3 D3S1358 4 5 D5S818 10 7 D7S820 5 8 D8S1179 22 Imagine you perform a PCR procedure to create a DNA profile for this individual. Which of the following four gels correctly represents the DNA profile of this person?

In the not-too-distant future, gene therapy may be used to treat many inherited disorders. What do you think are the most serious ethical issues to face before human gene therapy is used on a large scale? Explain

Today, it is fairly easy to make transgenic plants and animals. What are some safety and ethical issues raised by this use of recombinant DNA technology? What are some dangers of introducing genetically engineered organisms into the environment? What are some reasons for and against leaving such decisions to scientists? Who should make these decisions?

In October 2002, the government of the African nation of Zambia announced that it was refusing to distribute 15,000 tons of corn donated by the United States, enough corn to feed 2.5 million Zambians for three weeks. The government rejected the corn because it was likely to contain genetically modified kernels. The government made the decision after its scientific advisers concluded that the studies of the health risks posed by GM crops are inconclusive. Do you agree with Zambias decision to turn away the corn? Why or why not? In your answer, consider that at the time, Zambia was facing food shortages, and 35,000 Zambians were expected to starve to death over the next six months. How do the risks posed by GM crops compare to the risk of starvation?

From 1977 to 2000, 12 convicts were executed in Illinois. During that same period, 13 death row inmates were exonerated based on DNA evidence. In 2000, the governor of Illinois declared a moratorium on all executions in his state because the death penalty system was fraught with errors. Do you support the Illinois governors decision? What rights should death penalty inmates have with regard to DNA testing of old evidence? Who should pay for this additional testing?