What is Metamorphism?
Metamorphosis is a process in which animals like mammals, insects or even amphibians undergo rapid and extreme physical transformation sometime after birth. The process of metamorphosis can lead to changes in the entire body or simple changes in certain organs of the body. In addition to physical changes, an animal may undergo changes in their form of eating or breathing too. Common examples of metamorphism are the life cycle of a frog. In the life cycle of a frog, the animal transforms from a small tadpole to a frog. Moreover, the life cycle of a frog also experiences changes in the internal organs and systems.
Explain the Life Cycle of a Frog
The life cycle of a frog also known as frog metamorphosis begins at the egg stage. The females lay their eggs which then hatch into tadpoles. The second step of frog metamorphosis includes the development of gills. The tadpoles develop gills that help them to breathe underwater. It is also during this stage of frog metamorphosis that the tadpoles begin to develop lungs. In the third stage, a young tadpole develops into a small frog. A small frog learns how to swim with its hind legs. The most interesting part of a frog metamorphosis is that as the amphibian grows larger, it’s tail size reduces. When the frog turns into an adult it’s tail will disappear completely, and the animal will start to eat insects instead of greens. The cycle of frog metamorphosis keeps relegating as the adult frog will once again lay eggs and produce tadpoles.
What are the Frog Life Cycle Stages?
The frog life cycle stages begin from that of an egg and gradually develops into an adult frog. The intermediate stages include a tadpole and a young adult version of the amphibian. All the changes are accompanied by the physical and internal transformation.
Examples
1. Life Cycle of an Insect
Answer: In an insect life cycle, metamorphism occurs in every stage. At every stage, the insect looks different from what it did earlier. In some animals, we know that the traits from the previous form may remain. But in case of an insect life cycle, that does not happen. A very common example of complete metamorphism in insects is that of a butterfly. In the very beginning comes the larva. The larva has a massive appetite and can almost eat 10 times its body weight. The larva is basically a soft worm-like structure which hardens into the pupa. The out is a hard shell inside which a fully grown butterfly will be formed. The adult butterfly sheds the hard-shelled pupa and stretches out before flying high up in the sky. A few more examples of insects undergoing metamorphism are beetles, bees, ants and moths.
2. Name the Different Types of Metamorphism in Biology.
Answer: Based on the rate of change, metamorphism is of five types:
A metamorphic metamorphosis: It is the kind of metamorphism where the insects undergo very little change.
Gradual metamorphosis: In this kind of metamorphism that animal or insect develops changes over a gradual period of time.
Incomplete metamorphosis: Same as the previous type, in this kind of metamorphism the change comes gradually.
Complete metamorphosis: Complete metamorphosis includes a rapid change of the animal body.
Hyper metamorphosis: This type includes two to three different types of larva that develop into the insect.
Fun Facts of Frog Life
Frogs, usually, absorb water through their skin. Hence, do not have drinkable water.
In the complete life cycle of a frog, an adult frog can lay as many as 4,000 eggs.
Frogs are popularly known for jumping. Some of the frogs can jump as high as 20 times their own body weight in a single leap.
It is a common misconception that frogs are inky green in colour. There are a few frogs which are brightly coloured but very poisonous in nature.
At birth frogs have a long tail, but as they grow into adults the tail disappears.
Significance of Metamorphosis
One of the important components that contribute to the survival of insects is metamorphosis and hence it can be called a successful strategy. Many insects have juvenile phases with environments that are very distinct from the grownups. As a result, bugs can often make use of abundant food resources despite still being able to spread into other environments as adults. Metamorphosis dramatically increases the possibility for adaptability and development.
A Brief About Growth and Maturity
There is one thing to keep in mind when it comes to metamorphosis. Insects cannot mate or reproduce till they have completed their last moult or have emerged as a winged mature insect from a pupa. Wings aren't visible till the last moult, there are a few exceptions of course. When you observe an insect with wings, it means it has reached adulthood. This means that little flies do not grow larger; they just reach their maximum size.
Hormonal Control in Metamorphosis
Iodothyronine-induced metamorphosis is an ancestral trait of all chordates. Hormones produced by endocrine glands towards the front of the body control insect growth and metamorphosis. The prothoracicotropic hormone (PTTH) secreted by neurosecretory units in an insect's brain stimulates prothoracic glands, which emit another hormone, which is usually ecdysone, which causes ecdysis. The corpora allata, a retrocerebral organ, is also stimulated by PTTH, which produces the juvenile hormone, which blocks the growth of adult features after ecdysis.
Moults between larval instars have a significant amount of juvenile hormone, moults to the pupal phase have a lower degree of juvenile hormone, and the ultimate, or interoceptive, moult has no juvenile hormone at all in holometabolous insects. The amount of nymph instar stages in hemimetabolous insects can be influenced by juvenile hormone, according to experiments on firebugs.
Importance of Note-Making in Biology
Note-making is an important aspect of your preparation for the exams. Note-making helps build concentration and keep you proactive and interested during your study session. comprehending what you're learning and clarifying your thoughts selectively choose key concepts. It also saves time and helps you revise better especially in your end-time preparations.
FAQs on Metamorphism - Life Cycle of Frogs and Insects
1. What Animals have Metamorphism?
Amphibians undergo metamorphism the most in their life cycle. The life cycle of a frog undergoes various changes starting from that of a tadpole to an adult frog. An interesting fact about the frog life cycle stages is that during the metamorphism phase the amphibian lives in water. It is only after the complete transformation that the frog is able to live on land. Salamanders too have a life cycle much similar to that of a frog. At the larva stage, a salamander does not develop lungs or gills. It is during this time that the amphibian breathes through their skin membranes. The characteristic features of the frogs and salamanders at the tadpole stage are much similar.
2. What is Complete or Incomplete Metamorphosis?
The basic difference between complete and incomplete metamorphism is the number of life cycle stages linked with it. A Complete metamorphism has four stages associated with it: egg, larva, pupa and adult. On the other hand, incomplete metamorphism consists of three stages: egg, nymph, and adult. The nymph is present in the life cycle of insects such as cockroaches, beetles and bugs. The structure of a nymph is closely similar to that of an adult although it does not have any wings. Both complete and incomplete metamorphosis is also known as a gradual and simple form of metamorphosis. Other insects that show incomplete or complete metamorphism are fleas, ladybugs, mosquitoes, bees and termites.
3. Explain Metamorphosis in Amphibians?
Eggs are released in water and larvae are acclimated to an aquatic existence in ordinary amphibian metamorphosis. After that, newt larvae begin to hunt for food, whereas tadpoles grab food off surfaces using their sharp tooth grooves. The blood content of thyroxine, which drives metamorphosis, and prolactin, which inhibits it, govern metamorphosis in amphibians. Distinct tissues have certain threshold levels, which influence key details. Because most embryonic development occurs outside of the parental body, it is susceptible to several adjustments as a result of environmental factors. Tadpoles can have horny ridges for teeth, whiskers, and fins as a result of this. The lateral line organ is also used by them. These organs are obsolete after metamorphosis and are slowly replaced through apoptosis or regulated cell death. The quantity of adaptability to particular environmental settings is astounding, and many new discoveries are being produced all the time.
4. What is the theory of Metamorphosis?
Every biological species, we've known since Darwin, is the consequence of a metamorphosis: each species is simply a change like the one before it. This discussion will explore the organization of existence at its most radical authority: metamorphosis, using some of the most amazing occurrences such as the transition of a caterpillar into a butterfly. The notion that all life is unassignable to a unique anatomical and ecological origin, and that all living beings engage in a unified and unique existence that spans all kinds and species, is demonstrated. There is a breakdown of the stages of transformation into three categories i.e. mutation, nutrition, and sexuality.
5. How can students easily learn about Metamorphosis and prepare well for the exam?
Students can make a study plan of the topic Metamorphosis which should include the definition, a brief explanation, and types of metamorphosis mainly. After learning the basics students can prepare questions like the difference between the types of metamorphosis, its importance, its purpose, and its necessity. Students can also take help from Vedantu’s explanation about metamorphosis and other important topics from the subject. Planning a chapter or a topic is the best way to easily study and memorize it. It not only helps to remember the topic easily but also saves time.
