Biochemical changes, Biology

Assignment Help:

Biochemical Changes

Many workers have tried to follow the biochemical changes that precede flowering and result in meristems which give rise to flowers instead of vegetative structures. In Pharbitis, which is a short-day plant and requires only one dark period for flowering it was found that soon after the dark period, the flowering stimulus begins to move out of the leaves. In this experiment, the plant was given inductive conditions and after specific time intervals, biochemical changes were measured in meristems. An increase in metabolic activity around 40th hour at the floral apex was manifested by an increase in the level of RNA, proteins and ribosomes. Electron microscopic observations also revealed extensive formation of endoplasmic reticulum.

These activities were followed by an increase in DNA synthesis and mitotic activity. At about 88th hour after floral induction, the rate of cell division increased at apical and axillary meristems and the increase in cell division was noticed particularly in the central zone and peripheral zones of apical meristems. Such experiments have also been done in other plants. However, it has not been possible yet to identify which of the RNA or proteins are responsible for the onset of flowering. With the application of newer techniques it has been possible to suggest that there are some specific flowering genes which get switch on after receiving specific light-dark cycle. Although we do not know the products of all these genes, some of them have been shown to code for proteins which regulate transcription.


Related Discussions:- Biochemical changes

Deficiency diseases-post-parturient haemoglobinuria (pph), Post-parturient ...

Post-parturient haemoglobinuria (pph) in cattle and buffaloes The post-parturient haemoglobinuria (PPH) is an acute disease of high yielding buffaloes and cows. The disease oc

Respective functions of phospholipids, What are the respective functions of...

What are the respective functions of phospholipids, proteins and carbohydrates of the cell membrane? Ans) Membrane phospholipids have structural function they produce the bilipi

Factors affecting normal blood sugar levels, Q. Factors Affecting Normal Bl...

Q. Factors Affecting Normal Blood Sugar Levels? Earlier in our discussion, we learnt that insulin is the most important factor responsible for normal blood sugar levels. Now we

Extension cord causing injury, A 19 year old model for Glamour magazine tri...

A 19 year old model for Glamour magazine tripped over an extension cord causing injury to her epidermis. She is afraid the injury will leave a scar. Based on your knowledge of rege

Explain water holding or hydration capacity and viscosity, Explain Water Ho...

Explain Water Holding or Hydration Capacity (WHC) and Viscosity? WHC refers to the 'ability of fibre to bind water', just as dry sponge does when soaked in water. WHC of the fi

What is secretary diarrhoea, Q. What is Secretary diarrhoea? Secretary ...

Q. What is Secretary diarrhoea? Secretary diarrhoea: It is a result of active secretion OF electrolytes and water by the intestinal epithelium caused by bacterial and viral inf

Define prevention of idd by iodized oil, Define prevention of idd by Iodize...

Define prevention of idd by Iodized Oil? The other approach employed as a specific measure for women and children in hyper-endemic areas is injection of iodized oil. Intramuscu

Eggs of frog, EGG S OF FROG This egg is round & its diameter is of 1-2...

EGG S OF FROG This egg is round & its diameter is of 1-2 mm. It is mesolecithal & has distinct animal pole & vegital pole. The nucleus is found in the centre of the anim

What are the main features of the meristematic cells, What are the main fea...

What are the main features of the meristematic cells? Why do these cells require to have a high mitotic rate? Meristematic cells have very thin cell walls, small vacuoles, a 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