You Are Interested in Examining the Psf Gene $\quad$ $\quad$

question 31

Multiple Choice

You are interested in examining the Psf gene.It is known that Psf is normally produced when cells are exposed to high levels of both calcium (Ca²⁺) and magnesium (Mg²⁺) .MetA, MetB, and MetC are important for binding to the promoter of the Psf gene and are involved in regulating its transcription.MetA binds to the "A" site in the promoter region, MetB to the "B" site, and MetC to the "C" site.You create binding-site mutations in the A, B, and C sites and observe what happens to transcription of the Psf gene.Your results are summarized in Table Q8-12. $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\underline{\text { Transcription in the presence of } \mathrm{Ca}^{2+} \text { and/or } \mathrm{Mg}^{2+}}$
$\begin{array}{lcccc}\text { Binding sites present } & \begin{array}{l}\text { No } \mathrm{Ca}^{2+} \\\text { or } \mathrm{Mg}^{2+}\end{array} & \begin{array}{l}\text { With } \\\mathrm{Ca}^{2+}\end{array} & \begin{array}{l}\text { With } \\\mathrm{Mg}^{2+}\end{array} & \begin{array}{l}\text { With } \mathrm{Ca}^{2+} \\\text { and } \mathrm{Mg}^{2 *}\end{array} \\\hline \text { A, B, and C } & - & - & - & ++ \\\hline \text { none } & - & - & - & - \\\hline \text { A only } & - & - & + & + \\\hline \text { B only } & - & - & - & - \\\hline \text { C only } & - & + & - & + \\\hline \text { A and B only } & - & - & - & + \\\hline \text { A and C only } & - & + & + & ++ \\\hline \text { B and C only } & - & - & - & +\end{array}$

$\text {For this table: -= no transcription of Pst,}$
$\text {\( += \) low level of transcription of Psf, and}$
$\text {\( ++= \) high levels of transcription of Pst.}$


Table 8-12
Which transcription factors are normally bound to the Psf promoter in the presence of both Mg²⁺ and Ca²⁺?

• A)MetA and MetB
• B)MetB and MetC
• C)MetA and MetC
• D)MetA, MetB, and MetC

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Definitions:

BMI Cutoff

The threshold value of Body Mass Index that is used to categorize individuals into different weight statuses, such as underweight, normal, overweight, or obese.

Obesity

A medical condition characterized by excess body fat accumulation to the extent that it may have a negative effect on health, leading to reduced life expectancy and increased health problems.

Indicates

Suggests or implies something as a sign or symptom of a particular condition or situation.

Pancreatic Protease

Enzymes produced by the pancreas that break down proteins into smaller peptides.