Dormancy - plant growth substances, Biology

Assignment Help:

Dormancy - Plant Growth Substances

Dormancy can be defined as a state of suspended growth and metabolism. When most plants are exposed to seasonal periods of very inclement weather during which they would be damaged or killed if some protective mechanism did not exist. The most common safeguard against freezing cold or extreme dry heat is dormancy. Dormancy takes many forms like seed dormancy and bud dormancy. Dormancy as a state is marked by very low levels of water content; low metabolic rates, tolerance to low temperatures and dry conditions, etc. Dormancy is 'innate' (because of certain inbuilt causes and controlled genetically) in some cases or 'induced' by external factors in other cases. Induced dormancy is avoidable if dormancy inducible external factors are avoided.

Dormancy is a defense mechanism against winter frost or summer drought and is a necessary part of the lives of many plants. Dormancy must occur at the right time. It must last for a sufficient time, and it must be relieved or broken when the conditions are right for resumption of growth. There are, four basic questions that' must be asked about dormancy of a particular plant or organ. What are the environmental signals that start the process, and how are they perceived? What is the duration of dormancy? A timing mechanism appears to be necessary to ensure that the plant does not accidentally reawaken during unfavorable conditions. What is the nature of dormancy and what are the mechanisms for bringing about the dormant condition? Dormancy is not just an inactivation of metabolism, but frequently involves the development of specialised organs (for example, bud scales) or substances (for example, gummy waterproofing materials): Dormancy is evidently a programmed developmental event that requires specialised synthetic metabolism in addition to turning of metabolic activities.


Related Discussions:- Dormancy - plant growth substances

Events after sperm and egg fusion, Events after Sperm and Egg Fusion ...

Events after Sperm and Egg Fusion The entry of the sperm into the egg activates the egg. The activation of egg results in two types of responses. (1) The early responses a

Biomolecules, How do you explain in the absence of aldehyde group in the pe...

How do you explain in the absence of aldehyde group in the pentaacetate of D-glucose? Ans) when you react glucose with acetic anhydrate it forms pentaacetate with 5 OH grops it tel

Explain vitamin k as an essential fat soluble micronutrient, Explain Vitami...

Explain Vitamin K as an essential fat soluble micronutrient? Vitamin K is an essential fat-soluble micronutrient the only unequivocal role in health is in the maintenance of no

What are herbicide tolerant crops in ecological, What are Herbicide toleran...

What are Herbicide tolerant crops in ecological Herbicide tolerant crops (HTC)  Ecological  a)  Increased use of the herbicides that plant is  tolerant to (describes ecologi

Gene targeting in somatic cells, Gene targeting in somatic cells: Since t...

Gene targeting in somatic cells: Since the pioneering work with sheep at Roslin cloning by nuclear transfer has now been exemplified in a number of other livestock species includ

What are enzyme cofactors, What are enzyme cofactors? Some enzymes requ...

What are enzyme cofactors? Some enzymes require other associated molecules to work. These molecules are known as enzyme cofactors and they can be, for example, organic ions lik

Explain in brief about the extra-ocular muscles, Extra-ocular muscles ...

Extra-ocular muscles There are, as you know, six extra-ocular muscles. Out of these, four are recti(straight) and two are oblique. They control the position and movement of th

Describe the supra cardiac type of tapvc, Describe the Supra Cardiac Type o...

Describe the Supra Cardiac Type of TAPVC ? After connecting the baby to cnrdiopulmonary bypass, the common pulmonary venous channel is dissected. This lies behind the left atr

Explain the dna structure in details, Explain the DNA structure in details?...

Explain the DNA structure in details? Structure :  Each DNA molecule is a double stranded polymer, consisting of perhaps thousands or millions of linked nucleotides. The two

Explain angiosperms and flowering plants, Q. What are the angiosperms, the ...

Q. What are the angiosperms, the flowering plants? What is the major feature that distinguishes them from the gymnosperms? Flowering plants have seeds and flowers (phanerogamic

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