#Question id: 806
#Unit 1. Molecules and their Interaction Relevant to Biology
A single-stranded DNA molecule contains 40 nucleotides with equal amounts of A, C, G, and T. This DNA strand can combine with a complementary DNA strand to form a double-stranded DNA molecule. Which characteristic does this double-stranded molecule have when it forms a B-DNA structure?
#Question id: 4233
#Unit 3. Fundamental Processes
A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is __.
#Question id: 7112
#Unit 5. Developmental Biology
Although the vertebrate body plan outwardly displays a mirror-image symmetry with regard to left and right, the internal organs are not symmetrical. How does this left-right asymmetry develop?
#Question id: 5639
#Unit 5. Developmental Biology
In a comparison of plant and animal development, it is found that:
#Question id: 4508
#Unit 3. Fundamental Processes
Statement: In the case of group II introns, the chemistry of splicing and the RNA intermediates produced are the same as those for nuclear pre-mRNA.
Explanations: I. The intron uses an A residue within the branch site to attack the phosphodiester bond at the boundary between its 5’ end and the end of the 5’ exon-that is, at the 5’ splice site. This reaction produces the branched lariat.
II. A second reaction in which the newly freed 3’ -OH of the exon attacks the 3’splice site, releasing the intron as a lariat and fusing the 3’ and 5’ exons.