Biochemical changes, Biology

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.

Posted Date: 1/17/2013 7:26:22 AM | Location : United States







Related Discussions:- Biochemical changes, Assignment Help, Ask Question on Biochemical changes, Get Answer, Expert's Help, Biochemical changes Discussions

Write discussion on Biochemical changes
Your posts are moderated
Related Questions
Preparation on the Previous Day of Operation Remove all the jewellery, nail polish, cut nails.  The patient's body is cleaned - shaving from chin to toe, inclu

Bone Cells Bone cells may be divided into two broad classifications depending on whether they make bone or resorb it. Osteoblasts make bone, while Osteoclasts resorb or take aw

Discuss FASB and IASB. Comment on at least two specific aspect of the two standard setting boards and their role in setting accounting.

Explain about the Conjugated proteins? The phospho proteins and the metallo proteins are loose (as with phosphate carrying protein) or tight (as with the phosphate in casein or

Whey Protein Concentrates You already know that whey is the residual liquid substance that is obtained by separating the coagulum from milk during cheese making. There are imp

Define Nutritional Needs of the Elderly? In this, we learnt about the nutritional needs of the elderly, and in doing so we have also focused on many other aspects such as who d

Explain about the Artificial Sweeteners? As a group, artificial sweeteners are classed as "non-nutritive". Thus, they provide sweet sensation to the tastebuds, with no increasi

The blood vessels surrounding an acutely inflamed site usually represent progressive vasodilatation from the time of injury.

Define reagent required and methodology for picric acid test? Reagents  - Sugar solutions of glucose, fructose, galactose, lactose, maltose, sucrose and starch. - Saturat

Q. What do you mean by ST Hystersis? Ans. The rate of recovery of ST depression has been recognized as a measure of ischaemia severity for many years. When comparing the m