Which gene provides an example of the phenomenon of heterochrony?
A) A gene whose expression causes legs to form
B) A gene whose expression inhibits the formation of legs
C) A gene whose expression causes one segment to start growing sooner than it would in the absence of that gene expression
D) A gene whose expression affects more than one module
E) A gene that is expressed in a larger number of cells,causing a larger structure to form

Question

Quizplus · Accepted Answer

Heterochrony refers to changes in the timing of developmental events. A gene whose expression causes one segment to start growing sooner than it would in the absence of that gene expression exemplifies heterochrony by altering the timing of segment development. Genes that affect the formation of legs would not demonstrate heterochrony, as leg formation is a discrete developmental event rather than a temporal one. Gene expression affecting more than one module or cell number would be examples of modularity or cell signaling, respectively, rather than heterochrony.

Which Gene Provides an Example of the Phenomenon of Heterochrony