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#Question id: 378


Which of the following statements about buffers is true?

#XL - S Microbiology
  1. A buffer composed of a weak acid of pKa = 5 is stronger at pH 4 than at pH 6.

  2. At pH values higher than the pKa, the salt concentration is higher than that of the acid.

  3. The strongest buffers are those composed of strong acids and strong bases.

  4. When pH = pKa, the weak acid and salt concentrations in a buffer are equal.

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#Question id: 4621

#XL - T Zoology

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that

TLS Online TPP Program

#Question id: 1080

#XL - Q Biochemistry

 In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?

TLS Online TPP Program

#Question id: 4103

#XL - Q Biochemistry

In a biochemical experiment, you compare the products from splicing reactions carried out in vitro using three different substrates. In each case the substrate is a construct containing a single intron surrounded by two exons, and in all cases the construct is the same overall size. But in one case, the intron is a group I intron, in another a group II intron, and in the third an intron removed by the spliceosome. Each construct is labelled in a manner that allows it to be detected after gel electrophoresis, and each is tested in two reactions—one, conditions that support self-splicing, and two, in the presence of nuclear extract as well. Note that, for simplification, only the final products of the splicing reaction are seen, but before degradation of the introns.

 Which of the following observation is/are correct?

A. In lane A, the presence of nuclear abstract, a band for the lariat and the spliced product and pre-mRNA.

B. Lane B shows Group I Introns and Lane C is for Group II introns and reaction is nonself-splicing

C. Lane C is Group I intron. Splicing takes place in the absence and presence of nuclear abstract, and the reaction is self-splicing.

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#Question id: 20108

#XL - P Chemistry

Which of the following is zero during adiabatic expansion of the gas

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#Question id: 2054

#XL - S Microbiology

What is the single best defining feature of systemic lupus erythematosus (SLE)?