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

Show defense mechanism when inflammation fails, Q. What is the defense mech...

Q. What is the defense mechanism that begins to work when inflammation fails to stop an infection? If the inflammatory attack is not sufficient to halt the infectious process t

Taxonomy, Agroup of realated genera are classified as-?

Agroup of realated genera are classified as-?

Post-operative nursing care of cleft palate, Post-operative Nursing Care of...

Post-operative Nursing Care of Cleft Palate  Objective of Care  Provide adequate nutrition  Maintain oral hygiene  Apply restraints  Promote speech  Give

Levels of prevention, Family Centred Activities to Ensure Harmonious Relati...

Family Centred Activities to Ensure Harmonious Relationship: Between various members of  the family attitudes of mutual trust, love and respect for one another need  to be  fo

Determine about benefits of jogging, Determine about benefits of Jogging ...

Determine about benefits of Jogging Jogging gives a sense of wellness to a diabetic patient. The frequency of jogging should be at least 3 days in week with a distance of 2 km

Why ammoniotelic excretion occur, Why after the passage of animals from the...

Why after the passage of animals from the aquatic to the terrestrial habitat does the abandonment of the ammoniotelic excretion occur? Ammonia is a highly toxic molecule if not

Explain some physiological changes during pregnancy, Explain some Physiolog...

Explain some Physiological Changes during Pregnancy? A whole new life begins at conception. Organ systems develop rapidly and nutrition plays many supportive roles. Pregnancy f

Viscosity - blood flow, Normal 0 false false false EN-I...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain about the restriction enzymes, Which of the following is a false st...

Which of the following is a false statement regarding restriction enzymes? A. Restriction enzymes bind to a sequence specific element and disrupt the hydrogen bonds among

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