Metamorphism Life Cycle of Insects and Frogs (original) (raw)

Last Updated : 23 Jul, 2025

**Hormones play a significant role in the completion of the life cycles of insects and frogs and various other life forms like plants, animals, and humans. Hormones are chemical messengers transporting numerous important activities in almost every living form. In biological terms, metamorphosis is a process that occurs in an animal's body physically after birth or hatching during the development cycle. This process is considered the characteristic feature of insects like butterflies, houseflies, etc., and amphibians like frogs, toads, and many more. And hence, **hormones play an essential part in the metamorphosis of insects and frogs.

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**Metamorphosis is a biological process in which an animal develops physically including some stages of life such as birth transformation or hatching, involving morphological, physiological, and behavioral changes in the animal's body structure through cell growth and differentiation. Metamorphosis is also defined as a change from nymph or larva to adult. The result of this process changes the entire body of organisms.

The life cycle of frogs and insects consists of sequential phases of change. An adult silkmoth begins its life from an egg (oviparous). At last, it becomes a silkworm and later becomes a cocoon. After that moth develops from a cocoon. Moving towards the life cycle of a frog, it contains 3 stages. A frog's egg develops into a larva(tadpole) and later becomes an adult frog.

**Also Read: Difference between Ovivarous and Viviparous

Metamorphosis

Role of Hormones in Insects

Hormones in insects help to complete their life cycles or in other words, it plays a crucial role in their metamorphosis. There are some hormones that are primarily involved in the life history of insects. These are as follows:

**Ecdysteroids

Ecdysteroids are the hormones which are produced by the prothoracic glands. This stimulate the synthesis of new cuticle layers. Ecdysone are responsible for regulating molting and metamorphosis in insects. Its main function is to shed the old exoskeleton to grow into a new one during the molting.

**Juveniles Hormones

Juvenile hormone(JH) has the function of regulating the transition between larval stages and the metamorphosis in insects. This hormone is produced by the corpora allata glands. It promote the maintenance of larval characteristics while inhibiting the growth of adult features. Decreasing level of juvenile hormone means that the insect will undergo metamorohosis and transforms into an adult form.

Role of Hormones in Frogs

Metamorphosis in frogs that is the transformation of a tadpole into an adult frog is totally controlled by the hormone namely thyroxine. In frogs, thyroxine and gonadotropins hormone play an essential part in their life history. These are as follows:

**Thyroxine

The production site of thyroxine hormone is thyroid glands in frogs. Its major function is to regulate rate of metabolism and growth during different stages of development. A mineral called iodine is required by the thyroxine hormone for its synthesis and production. This hormone stimulates the growth of tissues, specially in the hind limbs and lungs in tadpoles. As the tadpole continue to undergo under the process of metamorphosis, the level of the hormone thyroxine increases, making the transformation of tadpole into an adult frog.

Gonadotropins

In frogs, the secretion site of gonadotropin hormone is the pituitary gland. Its major function is to control the development of the reproductive system and the production of the gametes. Gonadotropin is the stimulating hormone that stimulates the gonads to get mature (testes in male and ovaries in females). It also has a function of regulationg sex hormones like estrogen and testosteron, which are crucial for reproduction.

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