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.
explain hadzi''s theory with reference to metazoa
Emulsifying properties of proteins Proteins are the surface-active substances, which are extensively used in the food industry as emulsifiers to manufacture products such as d
Candidiasis Candidiasis (Moniliasis) is a disease of man, animals and birds and is caused chiefly by Candida albicans. Crop mycosis (thrush) of poultry is caused by C. albicans
Why is glucose such a good source of energy for bacteria? 1) Glucose contains six oxygen atoms, which can be used for oxidative phosphorylation and the generation of many ATP molec
Digestion in the Stomach To understand the digestion mechanism in the stomach, it is important to know about the anatomy of the stomach. Look up Unit 6, in the Applied Physio
Class of Crustacea - Copepoda Copepoda is a huge class of small (1-5mm) crustaceans occupying both marine and freshwater environments. Copepods form the several abundant and c
Two typical characters of the Hemichordata that can be observed and used to identify them are: i) Soft, worm-like or short unsegmented body. ii) Body is divided into a (i) pr
Q. How different are gymnosperms from pteridophytes and bryophytes? Gymnosperms are not cryptogamic as pteridophytes and bryophytes are. They are phanerogamic and so they form
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Secondary Growth in a Typical Dicotyledonous Stem In stem, the secondary growth in thickness in diameter is confined both intrastelar, i.e., in the stele and extrastelar regio
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