An exploratory expedition to a giant frozen lake present under Antarctica uncovers a bacterial species that has been isolated from the surface for a billion years. It is determined that the genetic information in this organism is encoded by the four bases A,
C, G and T, that DNA is transcribed and translated as in other organisms, there are three stop codons, but that the genetic code in this organism is nondegenerate and read in groups of two. Which of these statements is likely also to be true about this organism?
a) E. coli would most likely be able to translate mRNAs from this
organism
b) the tRNAs from this organism would have anticodons of four bases
c) 48 codons used by this organism do not encode amino acids
d) there are many more codons per amino acid in this organism than in
E. coli
e) Only 13 of the 20 standard amino acids are used to make proteins in
this organism
Which of these does not result in a conformational change in a protein that leads to
activation of gene expression?
a) binding of allolactose to Lac Repressor
b) binding of steroid hormone to a steroid hormone receptor
c) binding of inducer to GAL4
d) binding ofarabinose to AraC
e) binding of cAMP to CAP