Interaction of insect hormones, Biology

Assignment Help:

Interaction of insect hormones in the process of metamorphosis

The organs and the hormones usually included in metamorphosis of insects. This is since despite the fact that there may be around 1 million dissimilar insect species, there is a striking similarity in the endocrine function of dissimilar hemimetabolous and holometabolous insects. Figure depicts a schematic outline of the interaction of hormones in the metamorphosis of insects. On the basis of figure let us study how the actions of the several hormones bring about metamorphosis in insects. The moulting process, the beginning of metamorphosis, is initiated in the brain. The stimulus may be neural, hormonal or environmental, and causes the neurosecretory cells of the brain to release the activation hormone that after synthesis changes into the active hormone known as prothoracic opic hormone (PTTH). The PTTH stimulates the prothoracic gland to generate ecdysone.

Ecdysone after being transformed into its active form, the ecdysterone, stimulates growth and causes the epidermis to secrete a new cuticle, start the moulting process. The ecdysterone further stimulates the epidermal cells to synthesize enzymes which digest and recycle the components of the cuticle. As long as the juvenile hormone is present, the ecdysone-stimulated moult results in a new larval instar. In the last larval instar stage, the synthesis of juvenile hormone is decreased, causing its levels to drop below a critical threshold value. This again triggers the release of PTTH from the brain. The PTTH in turn, stimulates the prothoracic gland to secrete not usually large quantity of ecdysone. The resultant ecdysterone, in the relative scarcity of JH, causes the instar to pupate. In other word the occurrence of the subsequent moult in the larva in the relative scarcity of JH and abundance of ecdysone, shifts the organism from larva to pupa. Throughout the period of pupation the corpora allata do not release any juvenile hormone and the ecdysterone stimulates the pupa to metamorphoses into the adult insect.


Related Discussions:- Interaction of insect hormones

Hydra – metazoa, Hydra – Metazoa The animals of phyla Cnidaria and Cte...

Hydra – Metazoa The animals of phyla Cnidaria and Ctenophora are made up of only two germ layers: ectoderm which forms the outer covering of the animal and endoderm which is t

Explain the functions of consciousness, Q. Explain the Functions of Conscio...

Q. Explain the Functions of Consciousness? Consciousness allows individuals to be aware of his/her surrounding, thereby defining the context and removing ambiguities. Simplific

Determine the modification of food starches, Modification of Food Starches ...

Modification of Food Starches Positive attributes of starches can be greatly improved and/or negative characteristics diminished by slight and relatively simple modifications.

What is the original concentration, A sample of yeast cells was serially di...

A sample of yeast cells was serially diluted 1/10 five times then serially diluted 1/3. the number of yeasts was338 yeasts per ml. what was the original concentration? Please show

What are enantiomers, Enantiomers: Select one: a. Have the same molec...

Enantiomers: Select one: a. Have the same molecular weight b. Have the same connectivity c. Are mirror images d. Are non-superimposable e. All of the above

Elaborate the term - gill slits, Elaborate the term - Gill slits. Later...

Elaborate the term - Gill slits. Lateral opening in the wall of pharynx which allows water to enter into mouth and exit through the pharynx. This is one of the ancestral charac

What is the normal duration of the menstrual cycle, Q. What is the normal d...

Q. What is the normal duration of the menstrual cycle? How does the calendar contraceptive method work? The normal duration of the menstrual cycle is 28 days but it can vary am

Explain identifying features of rhizopus - food microbiology, Explain Ident...

Explain Identifying features of Rhizopus? Macroscopically Rhizopus appears as a white cottony mass (look at rhizopus growth on media above) growing rapidly and spread over enti

Y-linked traits in humans, Y-Linked traits in humans Any gene that occu...

Y-Linked traits in humans Any gene that occurs exclusively on the Y chromosome is said to be holandric and it is not expressed in females. Such a Y-linked gene normally occurs

Science class, Im learning about difference cell structures in science. I w...

Im learning about difference cell structures in science. I was wondering if I might be able to get some information about the epithelial tissue, and the connective tissue. Thankyou

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd