When transgenic organisms are made, the transgene may integrate into multiple sites within the genome. Furthermore, the integration site may influence the expression of the gene. For example, if a transgene integrates into a heterochromatic (i.e., highly condensed) region of a chromosome, the transgene may not be expressed. For these reasons, it is important for geneticists to analyze transgenic organisms with regard to the number of transgene insertions and the expression levels of the transgenes. Describes three methods (Southern blotting, Northern blotting, and Western blotting) that can be used to detect genes and gene products. Which of these techniques would you use to determine the number of transgenes in a transgenic plant or animal? Why is it important to know the number of transgenes? (Hint: You may want to use a transgenic animal or plant as breeding stock to produce many more transgenic animals or plants.) Which technique would you use to determine the expression levels of transgenes?

Discuss some of the worthwhile traits that can be modified in transgenic plants.

Evidence (see P.G. Shiels, A.J. Kind, K.H. Campbell, et al. (1999) Analysis of telomere lengths in cloned sheep. Nature 399, 316-17) suggested that Dolly may have been "genetically older" than her actual age would have suggested. As mammals age, the chromosomes in somatic cells tend to shorten from the telomeres. Therefore, older individuals have shorter chromosomes in their somatic cells than younger ones. When researchers analyzed the chromosomes in the somatic cells of Dolly when she was about 3 years old, the lengths of her chromosomes were consistent with a sheep that was significantly older, say, 9 or 10 years old. (Note: As described in the chapter, the sheep that donated the somatic cell that produced Dolly was 6 years old, and her mammary cells had been grown in culture for several cell doublings before a mammary cell was fused with an oocyte.)
A. Suggest an explanation for why Dolly's chromosomes seemed so old.
B. Let's suppose that Dolly at age 11 gave birth to a lamb named Molly; Molly was produced naturally (by mating Dolly with a normal male). When Molly was 8 years old, a sample of somatic cells was analyzed. How old would you expect Molly's chromosomes to appear, based on the phenomenon of telomere shortening? Explain your answer.
C. Discuss how the observation of chromosome shortening, which was observed in Dolly, might affect the popularity of reproductive cloning.

What is a chimera? How are chimeras made?

Not all inherited traits are determined by nuclear genes (i.e., genes located in the cell nucleus) that are expressed during the life of an individual. In particular, maternal effect genes and mitochondrial genes are notable exceptions. With these ideas in mind, let's consider the cloning of sheep (e.g., Dolly).
A. With regard to maternal effect genes, is the phenotype of such a cloned animal determined by the animal that donated the enucleated egg or by the animal that donated the somatic cell nucleus? Explain.
B. Does the cloned animal inherit extranuclear traits from the animal that donated the egg or from the animal that donated the somatic cell? Explain.
C. In what ways would you expect this cloned animal to be similar to or different from the animal that donated the somatic cell? Is it accurate to call such an animal a "clone" of the animal that donated the nucleus?

What is a recombinant microorganism? Discuss examples of recombinant microbes.

Recombinant bacteria can produce hormones that are normally produced in humans. Briefly describe how this is accomplished.

Discuss the advantages and disadvantages of gene therapy. Because a limited amount of funding is available for gene therapy research, make a priority list of the three top diseases for which you would fund research. Discuss your choices.

In the science lab, Wanda Ngo measures the following values of $x$ and $y$ :\

$$\begin{array}{ll}\frac{x}{11} & \frac{y}{341} \\ 18 & 411 \\ 23 & 471\end{array}$$

Wanda wants to know whether the function could be linear. Tell her the answer, and how you decided. If it is linear, find the particular equation. If it is not linear, assume it is quadratic and find the particular equation.

Charles Darwin once described a flower that produced nectar at the bottom of a tube nearly a foot deep ( 30 centimeters). He predicted that there must be a moth or other animal with a 30-centimeter-long "tongue" to match. He was right; it's a moth. Such specialization almost certainly means that this particular flower could be pollinated only by that specific moth. What are the advantages and disadvantages of such specialization?

Forensic Science An inequality that is used to calculate the height $h$ of an adult male from the length $r$ of his radius is

$$|h-(3.32 r+85.43)| \leq 4.57$$

where $h$ and $r$ are both in centimeters. Use this inequality to calculate the range of heights that an adult male with a radius of $26.36$ cm might reach, rounded to the nearest tenth of a centimeter.

The fracture strength of a certain type of manufactured glass is normally distributed with a mean of 579 MPa with a standard deviation of 14 MPa.

(a) What is the probability that a randomly chosen sample of glass will break at less than 579 MPa?

(b) More than 590 MPa?

(c) Less than 600 MPa? (Data are from Science 283 [February 26, 1999], p. 1296.)

The number of decibels, D, of a sound can be given by the equation D=10(log I+16), where I is the power of the sound measured in watts. Round to the nearest decibel. The loudest sound made by an animal is made by the blue whale and can be heard over 500 mi away. The power of the sound is 630 watts. Find the number of decibels of the sound emitted by the blue whale.

The Latin root -frict- means "to break." A refractory animal is one that "breaks away." The root -fract-*appears in some scientific and mathematical terms, such as fraction. A fraction is a part "broken away" from a larger whole. Explain how the root -fract- contributes to the meaning of below italicized word.
Although her motives were good, she was guilty of an infraction of the law