Iaa stimulates cell enlargement, Biology

Assignment Help:

IAA Stimulates Cell Enlargement

Cell wall contains layer of cellulose fibrils and are normally quite rigid. Thus for a cell to grow, there must be a mechanism for relaxing the cellulose fibrils. IAA releases the cross linking bands which hold the micro fibrils together. Auxin is thought to cause the walls to become plastic and them osmotic water intake causes the cell to swell like a balloon. American physiologist P.M. Ray has observed that IAA effect on elongation begins after a lag period of only 8-12 minutes, in tissues as coleoptiles. Recently it has been found that with certain auxins or even with IAA itself when used under correct conditions, the lag period can be reduced to 1 minute or less.

These effects are now considered to be as a result of activisation of proton pumps in membrane that pump protons in cell wall and cause a rise in acidity. Acidification loosens bonds in cell wall and cell wall plasticity increases. This rapid response is followed by activation of m-RNA translated into enzymes that catalyze synthesis of cellulose and other cell wall materials which cause the strengthening of elongated cell wall completing the cell elongation.


Related Discussions:- Iaa stimulates cell enlargement

Similaritie and difference between lamarckism and darwinism, What are the f...

What are the fundamental similarities and differences between lamarckism and darwinism? Both darwinism and lamarckism are evolutionary theories as opposed to fixism, both admit

Exercises and ambulation for cardiac patients, Exercises and ambulation ...

Exercises and ambulation Continue taking all exercises taught in the hospital. Steam inhalation may be continued. Walk on levelled space first, gradually increase the dista

Define arterial vessels - arterioles and arteries, Q. What are arterial ves...

Q. What are arterial vessels, arterioles and arteries? Arterial vessels are every blood vessel that carries blood from the heart to the tissues, arterioles and Arteries are art

External morphology of human heart, EXTERNA L MORPHOLOGY - Auricle ...

EXTERNA L MORPHOLOGY - Auricle 2 in number at broad area. Both are small, flap like cover ventricles like caps i.e. auricular appendix . It's skeleton is made up of mus

Functions of colour in foods, Q. Functions of Colour in Foods? Let us n...

Q. Functions of Colour in Foods? Let us now look at the different functions of colour in details, which are enumerated herewith: 1. The maturity of many fruits and vegetable

State the study of linked genes, Why is drosophila a convenient animal for ...

Why is drosophila a convenient animal for the study of linked genes? The fruit fly drosophila is suitable for the study of Genetics because it shows many distinct traits but on

How to prevent and control pem, How to Prevent and Control PEM? Any pr...

How to Prevent and Control PEM? Any programme aimed at prevention of PEM should be holistic and comprehensive considering the family as a unit. Since the effects of under nutr

Ventilation of tracheal system, Ventilation of Tracheal System The man...

Ventilation of Tracheal System The manner in which tracheae are ventilated varies with species of insects but movement of air is achieved in two ways: Diffusion

Caruncle - seed appendages, Caruncle - Seed Appendages This is a white...

Caruncle - Seed Appendages This is a white, collar-like structure borne on the micropylar end of the seed in many members of the Euphorbiaceae, such as castor, Ricinus communi

Explain the atp-sensitive potassium channel, ATP-sensitive potassium channe...

ATP-sensitive potassium channel?   A.  In smooth muscle cells surrounding an arteriole serving a region of the body that has just recently had very high levels of cellular acti

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