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

Hyphae and the mycelium of pluricellular fungi, Q What are the hyphae and t...

Q What are the hyphae and the mycelium of pluricellular fungi? The major structures of pluricellular fungi are the hyphae threadlike filaments made of contiguous uni or multinu

Complete feed system in ruminants, Complete feed system in ruminants C...

Complete feed system in ruminants Complete feed system for feeding dairy animals is a departure from conventional individual rationing method. It involves the self-feeding of

Name diseases caused by viruses, Name three diseases caused by viruses. ...

Name three diseases caused by viruses. There are many diseases caused by virus. Virus diseases include colds, influenza, herpes, mumps, measles, chicken pox, rubella, hepati

How a sample contaiinng this isotope decay, Please help with the following:...

Please help with the following: 32P is an unstable isotope of phosphorus that has a half-life of 14.29 days. Atoms of this isotope undergo beta decay in which a neutron decays i

Damage to the amygdalas may make a pearson fearless, Damage to the amygdala...

Damage to the amygdalas may make a pearson fearless. Gleb Shumyatsky's lab reported in an article in Cell (2005) that knock out mice [mice lacking a specific gene] lacking the gene

Carbon cycle, state 3 ways human activities add carbon to the atmosphere

state 3 ways human activities add carbon to the atmosphere

Obelia, why is it consideredto have an intermideate grade oforganisation

why is it consideredto have an intermideate grade oforganisation

Diseases caused by viruses, Diseases Caused by Viruses In the early day...

Diseases Caused by Viruses In the early days of microbiology, the disease producing submicroscopic agents were termed as 'filterable viruses' because of their ability to pass t

Explain about crossing over, What is crossing over? How is meiosis related ...

What is crossing over? How is meiosis related to this phenomenon? Linked alleles, for instance, A-b and a-B, form the gametes A-b and a-B that maintain the linkage of the allel

General nursing responsibilities in diagnostic procedure, GENERAL NURSING R...

GENERAL NURSING RESPONSIBILITIES IN DIAGNOSTIC PROCEDURE Let us understand what are the general responsibilities of nursing personnel while assisting in diagnostic procedure

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