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 is absorption, What is absorption?   Absorption involves  the  tr...

What is absorption?   Absorption involves  the  transfer of materials  through  the mucosa of the  alimentary tract  into blood and lymph vessels.

Define recommended dietary allowance for pyridoxine (rda), Define Recommend...

Define Recommended Dietary Allowance for pyridoxine (RDA)? Average requirements for pyridoxine vary with age, sex and physiological conditions such as protein status, pregnan

Explain the invasive species, Explain the Invasive species? Tens of tho...

Explain the Invasive species? Tens of thousands of non-native species have been introduced into the United States of America, with more arriving each year. These species can ha

Saturated fatty acids required for dyslipidemia, Q. Saturated Fatty Acids r...

Q. Saturated Fatty Acids required for dyslipidemia? Saturated Fatty Acids (SFA): These are found mostly in animal fats as white marble-like solid at room temperature. Red meats

Passage of pollen tube, Passage of Pollen Tube In cotton, the pollen p...

Passage of Pollen Tube In cotton, the pollen produces a tube within an hour which grows on the surface of the stigmatic hairs, and then between the cells of the stigma at the

Horse diseases-equine infectious anaemia, Equine infectious anaemia Eq...

Equine infectious anaemia Equine infectious anemia (EIA), an acute or chronic viral disease of the equines, shows intermittent fever, loss of weight, depression, progressive w

Define hormonal imbalance as a factor for obesity, Define Hormonal imbalanc...

Define Hormonal imbalance as a factor for obesity? Certain diseases associated with secretion of hormones, e.g., hypothyroidism, hypogonadism and Cushing's syndrome exhibit obe

Nursing process - bronchial asthma, Nursing Process Assessment ...

Nursing Process Assessment History, precipitating factors, current medication, medication used to relieve asthma symptoms. Any recent changes in medication regimen.

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