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.
Automated DNA sequencing is now common place which is based on the chain termination method but using a fluorescent dye attached to an oligonucleotide primer instead of using radio
what are he characteristic of phylum collenterata?
The calorific value of a fuel can be theoretically determined by using dulong's formula. It is assumed that heat evolved comes from the combustion of carbon, hydrogen, and sulphur
Why is the cerebellum more developed in mammals that jump or fly? The cerebellum is the major brain structure that coordinates the movement and the equilibrium of the body. For
Phylum Coelentrat a : (9,000 'species) The body is radial and made up of two cell layers. Gastro-Vascular cavity is saclike, tentacles and stinging cells are present. They may
CHARACTERSTICS OF CLEAVAGE - In cleavage involve the series of mitotic division, so daughter cells are genetically similar to the parental cell. The resulting cells are c
Q. Symptoms of malabsorption syndrome? The most common symptoms are weakness, lassitude and marked weight loss. Steatorrhoea (excess fat in stools), anaemia and chronic ill h
A fruit fly has four pairs of chromosomes in its cells. At meiosis, how many dissimilar combinations of maternal and paternal chromosomes are possible in the gametes? In gamet
describe the features of the rabbit femur bone
Explain Selective and Differential Culture Media? These are used for isolation of specific organisms. These are designed to isolate a group of closely related organisms and dif
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