The following pedigree shows the inheritance of a common phenotype controlled by an autosomal recessive allele. The probability of carriers in the population is 1/3. What is the probability that a child from parents III-3 and III-4 will show the phenotype?

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#Question id: 11161

#Unit 9. Diversity of Life Forms

The lakes of northern Minnesota are home to many similar species of damselflies of the genus Enallagma that have apparently undergone speciation from ancestral stock since the last glacial retreat about 10,000 years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species?

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#Question id: 9600

#Unit 9. Diversity of Life Forms

 Based on the tree below, which statement is not correct?

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#Question id: 4949

#Unit 11. Evolution and Behavior

What probably accounts for the switch to DNA-based genetic systems during the evolution of life on Earth?

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#Question id: 9583

#Unit 6. System Physiology – Plant

 A mechanism known as the Q cycle accounts for most of the observations in which structure and reactions of plastoquinone that operate in,

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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.