In marine sticklebacks, the Pitx1 gene is ____, but in freshwater sticklebacks, the Pitx1 gene is ____.
A) not expressed in fin buds of the pelvic region and spines are present; expressed and spines are absent
B) not expressed in fin buds of the pelvic region and spines are absent; expressed and spines are present
C) expressed and spines are present; not expressed in fin buds in the pelvic region and spines are absent
D) expressed and spines are absent; not expressed in fin buds in the pelvic region and spines are present
E) present so spines develop; absent so spines do not develop

Question

Quizplus · Accepted Answer

In marine sticklebacks, the Pitx1 gene is expressed, leading to the presence of spines. In freshwater sticklebacks, the Pitx1 gene is not expressed in fin buds in the pelvic region, resulting in the absence of spines. This difference is a key adaptation to their respective environments.

In Marine Sticklebacks, the Pitx1 Gene Is ____, but in Freshwater