<p>The Hardy-Weinburg principle is a hypothetical set of characteristics that is used in the study of population genetics. The principle states conditions necessary of a region in which evolution cannot happen-- no net mutations, no individual movement, random mating, no natural selection, and a large population-- in order to exemplify characteristics necessary for evolution to occur. The principle may be expressed in the expression p to the second power + 2pq + q to the second power = 1.0, where p equals the frequency of the dominant allele, q equals the frequency of the recessive allele, p to the second is equal to the dominant homozygous genotype, 2pq is equal to the heterozygous genotype, and q to the second is equal to the recessive homozygous genotype. </p>
<p>Explain how a negative feedback loop works.</p>
<p>For the lac operon, lactose is required to induce the operon since it combines with the repressor portion of the operon to make it inactive. This activates the transcription of proteins necessary for the enzymatic breakdown of lactose. These proteins, once properly modified, are deemed inducible enzymes.</p>
<p>For the trp operon, tryptophan acts as a corepressor. The presence of tryptophan from an external source allows the operon to halt it’s transcription since it is already in abundance. The enzymes produced from this process are deemed repressible enzymes.</p>
<p>Does anyone have the 2008 exam with the answers. need it to study. It wud be greatly appreciated. email: <a href="mailto:ballerahmad@yahoo.com">ballerahmad@yahoo.com</a></p>
<p>[ul] [li]CAM plants keep their stomates closed during the daytime to reduce excess water loss. They do this because they[/li][list]<a href=“A”></a> can fix CO2 into sugars in the mesophyll cells
<a href=“B”></a> can use photosystems I and II at night
<a href=“C”></a> modify rubisco so it does not bind with oxygen
<a href=“D”></a> can incorporate CO2 into organic acids at night
<a href=“E”>*</a> have lenticels instead of stomates [/ul][/list]</p>
<p>Could someone explain to me the difference between allosteric enzymes and noncompetitive inhibition? Is one inclusive of the other or something, because they seem very similar.</p>
<p>Noncompetitive inhibition is when there is more than one active site on an enzyme and the binding of one substrate to its active site prevents the binding of the other. This results from the transformations associated with enzymes once substrates bind to them.</p>
<p>Allosteric inhibition is when there is only one active site on an enzyme. However, there is also an allosteric site. When an inhibitor binds to the allosteric site, the active site changes conformation preventing the substrate from binding. Allosteric inhibition is also closely associated with feedback inhibition, where a metabolic pathway is shut down by its byproduct.</p>
<p>So the basic difference is that there is more than one active site for noncompetitive inhibition whereas there is only one active site involved in allosteric inhibition (although there may be one or more sites for an inhibitor to prevent binding of the substrate).</p>
<p>Not really, although I have heard some sexual innuendos regarding DNA polymerases’ function of “unzipping” genes, so to speak. But many of the rest really are not worth repeating here, nor worthy of any comical value, in my opinion.</p>
<p>[ul][li]In a population of 1,000 people, 90 have blue eyes. What percent of the population has hybrid brown eyes?[list][/li]<a href=“A”></a> 3%
<a href=“B”></a> 9%
<a href=“C”></a> 21%
<a href=“D”></a> 42%
<a href=“E”>*</a> 49%[/ul][/list]</p>