Question

If thyroxine is added to a beaker that has some small tadpoles then:
A. All tadpoles die.
B. They metamorphose very fast.
C. They develop a small body.
D. They develop a giant body.

Answer 1

Hint: Thyroxine is a hormone that is necessary for all vertebrates, including humans, to grow and develop. When it is injected into a young tadpole, its metamorphosis is accelerated, and it becomes a frog quickly.

Complete Step by Step Answer:
Thyroxine is a thyroid hormone that tends to increase metabolic rate or the body's metabolism. It regulates the rate at which oxygen and food react to produce energy for the body to use. Thyroxine is also essential for growth and development. Negative feedback regulates its levels.
Metamorphosis is a huge shift in an individual's form or structure that occurs after hatching or birth in biology. Molting as well as juvenile hormones, which are not species-specific, appear to control the changes. Physical changes, as well as growth and differentiation, are associated with changes in the organism's physiology, biochemistry, and behavior.

The correct option is (b)

Additional information: The tadpole, an aquatic larval stage that morphs into a land-dwelling frog, is an illustration of metamorphosis (class Amphibia). Starfish and other echinoderms go through a metamorphosis that includes a shift from the larva's bilateral symmetry to the adult's radial symmetry.

Note: While it is normal for not all tadpoles to sustain to adulthood, there are some cases where more tadpoles are dying than expected. In general, poor nutrition, contaminated water, a lack of space, and illnesses can all contribute to high mortality rates in tadpoles, not thyroxine. Instead, thyroxine helps in the development of tadpoles.