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 do you understand by mesocoel, What do you understand by Mesocoel? ...

What do you understand by Mesocoel? The middle of three coelomic spaces found in tripartate body plan characteristic of deuterostome lineage of animals. Other coelomic compartm

Define physical activity as a factor for obesity, Define Physical activity ...

Define Physical activity as a factor for obesity? Sedentary life style with lack of an exercise schedule tends to make one obese. As we approach middle age, our physical activi

Mismatch and recombinational repair, Q. Mismatch and Recombinational repair...

Q. Mismatch and Recombinational repair? Mismatch repair: 1. Mismatches can take place when DNA polymerase inserts wrong nucleotide during replication 2. Mismatch repair is

Symptomatic patient-chronic mitral regurgitation, Symptomatic patient: Sy...

Symptomatic patient: Symptomatic patient (class 11, 111 or IV) with severe MR and normal left ventricular function (EF > 0.6) and end systolic dimension of LV

Absorption of lipids, Absorption of lipids Absorption of lipids is qui...

Absorption of lipids Absorption of lipids is quite different from the absorption of monosaccharides and amino acids. Figure shows the process. The free fatty acids, monoglycer

Blood from a donor is sterile and stored in a sealed bag, Blood from a dono...

Blood from a donor is sterile and stored in a sealed bag, but it is still kept at 4°C. What is the advantage of keeping it at this low temperature?   At 4 °C, enzyme activi

Natural selection, Which of the following statements is most acceptable fro...

Which of the following statements is most acceptable from an evolutionary point of view? (a) Apes and humans have evolved from a common ancestor. (b) Humans have evol

Immediate post-operative care to a cardiac patient, Immediate Post-operativ...

Immediate Post-operative Care The patient is accompanied to the ICU by a surgeon, anesthetist and the nurse who assisted for the surgery with portable ventilator and ECG

Sample titration - estimation of nitrogen & protein content, Define Sample ...

Define Sample Titration - Estimation of nitrogen and protein content? Take the given ammonium sulfate solution into a 100 ml volumetric flask and dilute to the mark with distil

Mounting boxes for insect collections, Mounting boxes for insect collection...

Mounting boxes for insect collections Wood or cardboard cigar boxes make very useful and suitable housings for insect collections. After the insect has been separate from the 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