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

Define estimation of blood thiamin levels - thiamin status, Define Estimati...

Define Estimation of Blood Thiamin Levels - Thiamin Status? The levels of free thiamin and its phosphoesters in whole blood and erythrocytes are measured using high- performanc

Explain in detail about male reproductive system, Explain in detail about M...

Explain in detail about Male Reproductive System The male reproductive organ consists of the following:  A pair of testes, held in scortum; produces spermatooa and testoster

Explain adverse effects of ketoconazole, Explain Adverse Effects of ketocon...

Explain Adverse Effects of ketoconazole Anorexia, nausea and vomiting are common with higher doses (>400 mg/day) of ketoconazole; taking the drug with food or at bedtime may i

Aquatic biomes, If you look up a world atlas you would notice that most of ...

If you look up a world atlas you would notice that most of the earth's surface is covered by the waters of the oceans (about 71%). Beneath the water surface is a fascinating world

Life forms, why are life forms significant?

why are life forms significant?

Population growth, Increase in population size is known as population growt...

Increase in population size is known as population growth. It depends upon number of persons added to the population and number of persons lost from the population. Addition in pop

What is energy, What is Energy ? Energy Energy is defined as the cap...

What is Energy ? Energy Energy is defined as the capacity to do work. Work is defined as the movement of a mass, or the product of the force and the distance through which t

What is hemodialysis, What is hemodialysis? Hemodialysis is the artific...

What is hemodialysis? Hemodialysis is the artificial blood filtration made by exact machines in substitution of the kidneys. Hemodialysis may be essential in patients suffering

Define the term ancestral characteristic, Define the term Ancestral charact...

Define the term Ancestral characteristic A character shared by all members of a taxonomic group of organisms (taxon) and used to define the unique nature of the group. The cha

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