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 microbiological apparatus and equipments, Explain Microbiological A...

Explain Microbiological Apparatus and Equipments? It provides an orientation to the various basic equipments, i.e., instruments, tools, glassware and miscellaneous items used i

Pseudopodia – protozoans, Pseudopodia – Protozoans Pseudopodia are flo...

Pseudopodia – Protozoans Pseudopodia are flowing cytoplasmic protrusions of the cell causing amoeboid movement. In protozoans pseudopodia exist in several forms. The most fami

Which is most likely be fatal to marin fish populations, If we were to comp...

If we were to completely eliminate one group of marine organisms from ocean, which would most likely be fatal to Marin fish populations? Elimination of: a) Starfishes b) Dia

Why biologists use comparative method, Normal 0 false false ...

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

What would the priorities be for allocating, Agriculture, industry, and gro...

Agriculture, industry, and growing populations of cities all compete, through political influence, for water. If you were in charge of water resources in an arid region, what would

Explain thetechnique of total anomalous surgery, Explain theTechnique of to...

Explain theTechnique of total anomalous Surgery ? Corrective surgery is undertaken as an emergency procedure after diagnosis has been confirmed by two-dimensional echocardiogra

Sporophytic and gametophytic self-incompatibility, Sporophytic and Gametoph...

Sporophytic and Gametophytic Self-Incompatibility Besides the categories based on morphology, self incompatibility can be further classified into sporophytic or gametophytic t

Show extraembryonic membranes present in vertebrates, Q. What are the extra...

Q. What are the extraembryonic membranes present in vertebrates? The extraembryonic membranes that may be present in vertebrates are the yolk sac, the amnion, the placenta, the

Explain in brief about the extra-ocular muscles, Extra-ocular muscles ...

Extra-ocular muscles There are, as you know, six extra-ocular muscles. Out of these, four are recti(straight) and two are oblique. They control the position and movement of th

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