A researcher studying the development of the eye in Xenopus (the clawed frog) is testing her hypothesis that the optic vesicle induces head ectoderm to form the lens of the eye.When she removes the optic vesicle on one side of the embryo, no lens forms on that side, indicating the optic vesicle is necessary for lens formation.What additional experimental result must she obtain to show that the optic vesicle is also sufficient for inducing lens formation?
A) The lens forms when a permeable barrier is placed between the optic vesicle and the lens-forming tissue.
B) The lens does not form when an impermeable barrier is placed between the optic vesicle and the lens-forming tissue.
C) A lens forms when the optic vesicle is placed next to tissue that does not normally form a lens.
D) A lens does not form when the optic vesicle is placed next to tissue that does not normally form a lens.
E) A lens forms when the optic vesicle is recombined with lens-forming tissue.

Question

Quizplus · Accepted Answer

To demonstrate that the optic vesicle is sufficient for lens formation, the researcher needs to show that its presence alone (without other specific conditions or tissues that normally induce lens formation) can induce lens formation in tissues that do not normally develop into a lens. Option C, where a lens forms when the optic vesicle is placed next to tissue that does not normally form a lens, directly tests and supports the sufficiency of the optic vesicle for lens induction.

A Researcher Studying the Development of the Eye in Xenopus