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

What are the main characteristics of the age pyramids, What are the main ch...

What are the main characteristics of the age pyramids of developed countries? In a stabilized human population the age pyramid has a narrower base as the reproduction rate is

Explain the health economics, Explain the Health Economics? Health econ...

Explain the Health Economics? Health economics concentrates on application of the principles and rules of economics in the sphere of health. In broad terms, it includes analysi

Define the beer''s law - nutritional biochemistry, Define the Beer's Law -...

Define the Beer's Law - Nutritional  Biochemistry? Beer's law states that the concentration of a substance is directly proportional to the amount of light absorbed or inversely

Which are plant tissues that form the plant roots, Which are plant tissues ...

Which are plant tissues that form the plant roots? Roots have a central portion called medulla made of vascular tissue outer phloem and inner xylem. Medulla is delimited by per

What is starch , Starch exists in plants as insoluble starch granules in c...

Starch exists in plants as insoluble starch granules in chloroplasts.  Each starch granule   holds   a   combination   of   two   polysaccharide    forms, amylopectin and amylose.

Under nourished persons - nutritional intervention using mna, Define Under ...

Define Under nourished persons - nutritional intervention using MNA? An MNA score below 17 indicates that the patient is suffering from under nutrition.  Thus in this situatio

Haematology, differenciate between plasma and serum

differenciate between plasma and serum

Biodiesal, Diesel-like liquid obtained from materials of biological origin ...

Diesel-like liquid obtained from materials of biological origin is called biodiesel. Biodiesel can be obtained (i) either from lipids accumulated plants and algae or (ii) from

Describe the mechanism responsible for the cessation, Describe a. the facto...

Describe a. the factors responsible for promoting lactation, and b. the mechanism responsible for the cessation of lactation when a mother weans her baby.

Sample titration - estimation of vitamin c in a solution, Define Sample Tit...

Define Sample Titration - estimation of vitamin c in a solution? Take the given unknown solution provided to you in a 100 ml volumetric flask. Dilute the sample ascorbic acid s

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