Question

Some breeds of dogs that are specialized to retrieve objects from bodies of water have webbing between their toes.

A change in what cellular response to positional information during digit formation could account for this morphological feature?
A. signals that cause differentiation to toes are not received by cells that become webbing
B. signals to cause apoptosis are not received by cells that become webbing
C. cells between the future digits migrate, but do not divide once they are in the region that will become toes
D. cells between the future digits divide, but do not migrate to the region that will become toes
E. cells between the future digits do not divide before migrating to the region that will become toes

Answer 1

Dog breeds with webbed toes have a change in cellular apoptotic signal reception, preventing apoptosis and therefore retaining the webbing between their digits.

Step-by-step explanation:

The morphological feature of webbing between the toes of some dog breeds that specialize in retrieving objects from water can be explained by a change in the cellular response to apoptotic signals during digit formation. Specifically, the change is B. signals to cause apoptosis are not received by cells that become webbing. Apoptosis, a form of programmed cell death, normally removes the tissue between digits, leading to separate fingers and toes. However, in the case of dog breeds with webbed toes, the lack of apoptosis in the cells that would normally be eliminated results in the retention of the webbing.