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

What is the thermopenetration concept, What is the thermopenetration concep...

What is the thermopenetration concept? The pasteurization of products packed in glass containers leads to a problem of a specific nature, which is referred to as 'thermopenetra

Determine the tenant of the cell theory, Determine the tenant of the Cell T...

Determine the tenant of the Cell Theory Which of the following is not a tenant of the Cell Theory as postulated by Mathias Schleiden and Theodor Schwann? A. All organisms a

Define protein requirement during thyphoid, Protein Protein: The requir...

Protein Protein: The requirement of protein is increased in typhoid, as  there  is  a massive tissue loss. Thus, the protein intake should be increased above the normal of  lg/

x linked traits in humans, X-Linked Traits in Humans Let us first exam...

X-Linked Traits in Humans Let us first examine traits determined by genes on the X-chromosome, or the X-linked traits. The human X chromosome contains many genes that are requi

Explain how a human eye is working for the body, Explain how a human eye is...

Explain how a human eye is working for the body. Every tissue in the body requires basic components which are either derived from the body itself or we acquire them from extern

List the four objectives of counselling a diabetic patient, Q. List the fou...

Q. List the four objectives of counselling a diabetic patient? Objectives of Diabetes Counselling 1. Facilitating decision to start treatment and change life style 2.

Blastocyst, Blastocyst is the developmental stage of fertilized ovum by th...

Blastocyst is the developmental stage of fertilized ovum by the time it is prepared to implant; formed from morula and comprises of an internal cavity, an inner cell mass, and an

Define the bioavailability of cyanocobalamin, Define the Bioavailability of...

Define the Bioavailability of cyanocobalamin? Vitamin B 12 is widely available. Availability is more from non-vegetarian foods as described earlier under the food sources sec

What are biogeochemical cycles, What are biogeochemical cycles? Biogeoc...

What are biogeochemical cycles? Biogeochemical cycles are representations of the circulation and recycling of matter in nature. The major biogeochemical cycles studied in Ec

Define causes of iodine deficiency disorders, Define Causes of iodine defic...

Define Causes of iodine deficiency disorders? We have studied above that iodine deficiency is a naturally occurring ecological phenomenon that is present in many parts of the w

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