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

A plant growing on a mountainside, What two abiotic factors might affect (a...

What two abiotic factors might affect (a) an animal living at the bottom of the sea, (b) a plant growing on a mountainside?   (a) The abiotic factors which might

Explain the s1m filament theory of muscle contraction, Explain the s1M fila...

Explain the s1M filament theory of muscle contraction. What is special of "FlavrSavr" variety of tomato? Why is it preferred to its normal native variety? Illustrate a label

Define paediatric problems and nutritional management, Define Paediatric Pr...

Define Paediatric Problems and Nutritional Management? The process of accepting and digesting food in adequate amounts to meet nutrition needs is termed as feeding. Certain gro

What is the main external morphological feature, What is the main external ...

What is the main external morphological feature that differentiates platyhelminthes from other worms (nematodes)? Platyhelminthes are also called as flatworms because they are

Coelenterata, mode of digestion in coelenterata

mode of digestion in coelenterata

Why hydrogen bonds are so important, Even though hydrogen bonds are conside...

Even though hydrogen bonds are considered weak chemical bonds, why they are so important, give an example.

Hypoglycaemia unawareness, Hypoglycaemia Unawareness ? Some people ...

Hypoglycaemia Unawareness ? Some people with diabetes do not have early warning signs of low blood glucose, a condition called hypoglycemia unawareness. ? This conditio

Summary of economic dimensions of financing healthcare, Normal 0 ...

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

Is fecundation in amphibians internal or external, Q. Is fecundation in amp...

Q. Is fecundation in amphibians internal or external? In this aspect are amphibians evolutionarily proximal to fishes or to reptiles? In the majority of the amphibian species f

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