Senescence, Biology

Assignment Help:

Senescence

Plants begin their development after seed germination. They grow, flower and finally senesce and die. The period from the start to death is called the longevity or age or life span and this period varies from species to species. For example, some plants, like annuals, complete their life cycles within a few months whereas others live for a few centuries. For example, the life of Juniperus scopulorum is around 3,000 years. The period just before death is called the senescent period.

This may be compared to old age in animals. In this period deterioration occurs because there is a consistent decrease in viability and increase in vulnerability. This phase can be prolonged but cannot be reversed. Senescence may occur very quickly or may be a very slow process. In a plant sometimes the individual organs senesce while the whole plant may remain healthy. In annuals, the whole plant dies; in biennials, the plant dies only after two years, whereas in perennials, year after year the leaves and fruits are shed but the main plant survives.


Related Discussions:- Senescence

Explain natural classification, Natural Classification Natural classifi...

Natural Classification Natural classification is based on the natural characters of the taxa. Some consider natural classification a phylogenetic one reflecting the evolutionar

Explain erythema migrans, Erythema migrans Oral antibiotic therapy sho...

Erythema migrans Oral antibiotic therapy shortens the duration of the rash and generally prevents development of late sequelae. Among the 3 drugs used for this indication, onl

How cholera is generally spread in humans, How cholera is generally spread ...

How cholera is generally spread in humans Associated Foods: Cholera is generally a disease spread by poor sanitation, resulting in contaminated water supplies. Sporadic cases o

Illustrate food applications of cmc, Food applications of CMC In common...

Food applications of CMC In common with other linear water-soluble polymers, cellulose gum solutions are pseudoplastic that is the viscosity decreases as the  rate of shear inc

What is the evolutionary importance of pteridophytes, Q. What is the evolut...

Q. What is the evolutionary importance of pteridophytes? As the first pteridophytes, tracheophytes were also the first plants to extensively colonize the terrestrial environmen

Oxidation of unsaturated fatty acids, Unsaturated fatty acids require some ...

Unsaturated fatty acids require some additional processing before they can be degraded completely by β-oxidation.  The Unsaturated fatty acyl CoAs with double bonds at odd-numbered

Respective functions of phospholipids, What are the respective functions of...

What are the respective functions of phospholipids, proteins and carbohydrates of the cell membrane? Ans) Membrane phospholipids have structural function they produce the bilipi

Use of propionates acid in microorganisms, Q. Use of Propionates acid in mi...

Q. Use of Propionates acid in microorganisms? Propionic acid is formed from lactic acid or lactates, as a result of the bacterial action during the manufacturing of swiss chees

Define protein requirement during thyphoid, Protein Protein: The requir...

Protein Protein: The requirement of protein is increased in typhoid, as  there  is  a massive tissue loss. Thus, the protein intake should be increased above the normal of  lg/

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