Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
What is parasitism? Parasitism is the ecological interaction in which a being lives at the expense of another. The parasite often does not cause immediate death of the host sin
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Define the Dietary Management for Underweight? We just read about the etiological factors that may lead to undernutritioin and weight loss. Whatever may be the cause, all under
Self Help Group: The first and perhaps the most influential of substance abuse rehabilitation is Self Help Group. The self help programme was founded in 1935 by two men, Dr. B
Explain Transposition the Great Arteries with Ventricular Scptal Defect ? Transposition of the great arteries with VSD is an indication for surgery. It is preferable to do VSD
Phylum Myxornycetes 1) They are known as cellular slime moulds mostly grow in damp places e.g. soil and rotting tree trunks. 2) They have a curious life-cycle in which free
What are the Consequences of PEM? The consequences of PEM are most often long lasting and irreversible. The common consequences include: • Irreversible growth retardation
Valacyclovir (Valtrex) - Valacyclovir is an L-valyl ester of acyclovir that is metabolized to acyclovir after oral administration, resultingin higher serum concentrations than
Which are growth tissues of plants? How do they categorize and where can they be found? Growth tissues of the plants are the meristems. The Meristems are the tissues that produ
Sarcodine protozoans are amoebas, and there are two types of them: shelled and naked. As you examine the prepared slides you should be able to see water expulsion vesicle, nucleus,
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd