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

Intermediate filaments - role of cytoskeleton structures, Intermediate fila...

Intermediate filaments - Role of Cytoskeleton Structures These filaments are intermediate in size among microtubules and microfilaments and are 10 nm in diameter. Five classes

circulation patterns, Normal 0 false false false EN-IN...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Homeostais, what is homeostasis and how does it happen

what is homeostasis and how does it happen

Mollusca, An account of characters of mollusca

An account of characters of mollusca

What is cholesterol, Q. What is Cholesterol? In its free, unesterified ...

Q. What is Cholesterol? In its free, unesterified form cholesterol is a major component (together with phospolipid) of cell membranes. Its presence helps to stabilize membrane

How to evaluate blanching efficiency, How to evaluate blanching efficiency?...

How to evaluate blanching efficiency? Finally, let us learn how to evaluate blanching efficiency? Normally, two of the more heat resistant plant enzymes, namely peroxidase and

Agama lizard, excretory system in agama lizard

excretory system in agama lizard

What is class asteroidea, What is Class Asteroidea ? Sea stars are prob...

What is Class Asteroidea ? Sea stars are probably one of the most recognizable of all Echinoderms. Often beautifully colored and symmetrical, they are predators that feed vorac

Explain the copper toxicity in human, Explain the Copper Toxicity in Human?...

Explain the Copper Toxicity in Human? Acute copper toxicity in humans is rare and occurs due to inadvertent consumption of copper salts. Symptoms include vomiting, diarrhoea, h

How the slides and specimens used as instructional resources, Explain how t...

Explain how the slides and specimens used as instructional resources?  Ans) They act as an Identifier, so that we can judge them simply

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