We know hormones have a very influential role in human life. The sex hormones help to achieve sexual maturity in boys and girls. Hormones other than sex hormones perform other particular body functions. The variation in the level of different hormones in the blood leads to many disorders. Even though these disorders can be controlled, they are not completely curable. Like humans, other animals also have hormones in their blood. Let’s see how these hormones influence the life cycle of an organism like frogs and insects and causes metamorphism.
Metamorphism and Hormones
Viviparous animals give birth to young ones while oviparous animals lay eggs, which eventually grow and become adults. The majority of animal’s offspring look similar to their adults by birth. But there are few organisms which appear to be different from their adults. In their lifecycle, they undergo many changes.
The life cycle of frogs and insects involve sequential stages of change. An adult silk moth starts its life from an egg. Eventually, it becomes a silkworm and later becomes a cocoon. At last stage, a moth develops from the cocoon. If we consider the life cycle of a frog, there are three stages. Eggs of a frog develop into a larva (tadpole) and later become an adult frog. These drastic changes in appearance and stages are not as lengthy as human growth. The changes in the stages from a larva to an adult are known as metamorphism.
Metamorphism is a hormonal effect. Metamorphism in frogs is controlled by the hormone called thyroxine. The hormone produced by the gland called thyroid. For the production of thyroxine, thyroid gland needs iodine. Frogs need to live in water bodies where sufficient iodine is present for thyroxine production. Hence, deficiency of iodine can retard the growth of a larva to become an adult frog. Metamorphism in insects is also a result of hormonal activity in them.
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