[Campbell Biology P.436] According to Figure 18.22 and the accompanying text, which statemen... | Practice Question

According to Figure 18.22 and the accompanying text, which statement accurately describes the distribution of bicoid mRNA and Bicoid protein during early Drosophila development?

  • A: *bicoid* mRNA is concentrated at the anterior end of the unfertilized egg, and Bicoid protein forms a gradient highest at the anterior end in the early embryo.
  • B: *bicoid* mRNA is initially uniform, and Bicoid protein concentrates at the posterior end.
  • C: Both *bicoid* mRNA and Bicoid protein are uniformly distributed throughout the egg and embryo.
  • D: Bicoid protein is found only in the unfertilized egg, not the early embryo.

Explanation

Figure 18.22 and the 'Results' section state that bicoid mRNA is confined to the anterior end of the unfertilized egg. After fertilization and translation, Bicoid protein is seen to be concentrated in cells at the anterior end of the embryo, forming a gradient. This directly matches option A.