If the sequence of only one strand is known for primer synthesis, the best PCR variant that allows amplification of DNA with only one known sequence is

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#Question id: 11163

#Unit 9. Diversity of Life Forms

The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that

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#Question id: 14685

#Unit 4. Cell Communication and Cell Signaling

In dark-adapted rod cells, a high level of cGMP keeps cGMP-gated nonselective cation channels open, leading to hyperpolarization of the plasma membrane and neurotransmitter release. 

B - Light absorption generates activated rhodopsin, R*, which binds inactive, GDP-bound Gαt protein and mediates the exchange of GDP for GTP . 

C- The free Gαt∙GTP activates PDE by binding to its inhibitory γ subunits and dissociating them from the catalytic α and β subunits . Relieved of their inhibition, the α and β subunits of PDE hydrolyze GMP to cGMP . 

D- The resulting decrease in cytosolic cGMP leads to dissociation of cGMP from the cation channels in the plasma membrane and the closing of those channels . 

E- The membrane then becomes transiently hyperpolarized, and neurotransmitter release is reduced. 

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#Question id: 18615

#Unit 13. Methods in Biology

PCR efficiency is influenced by several factors, the efficiency declines due to

a) efficiency of amplification declines with an increase in the length of the target sequence.

b) Efficiency of PCR is affected by primer length; it declines if the primers used for PCR arc too long.

c) a temperature higher than the ideal annealing temperature reduces PCR efficiency.

d)  primers used for PCR have complementary regions, dimers will be formed, and PCR efficiency will decline.

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#Question id: 1442

#Unit 4. Cell Communication and Cell Signaling

Transgenic mice that express an activated oncogene like rasD under the control of the TetOFF system are likely to undergo which of the following events when tetracycline is given?

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#Question id: 3990

#Unit 3. Fundamental Processes

Which of the following statements is true of the attenuation mechanism used to regulate the tryptophan biosynthetic operon in E. coli?