Multiple choice If a frog's tadpole produces too much thyroxin, _____. metamorphosis occurs earlier metamorphosis is late metamorphosis will never take place it dies Reveal answer Fill a bubble to check yourself A Correct answer Explanation Thyroxine controls metamorphosis timing in frogs. Excess thyroxine accelerates development, causing earlier metamorphosis. Too little thyroxine delays or prevents metamorphosis. This is a key example of hormonal timing control.