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 root-end resection apicoectomy, Define Root-End Resection Apicoectom...

Define Root-End Resection Apicoectomy a. Examine the root surface before cutting for: cracks, anatomical variations, and quality of orthograde obturation. b. Cut the root en

What are the diagnostic models, Diagnostic Models Study models made fro...

Diagnostic Models Study models made from impressions of the arches are invaluable for diagnosis and treatment planning. The model must be mounted on an adjustable or semi adjus

What are some antibiotics used against fungi, Q. What are some antibiotics ...

Q. What are some antibiotics used against fungi? The systemic or topical azoles (like fluconazole, itraconazole and others), amphotericin B, the echinocandins (caspofungin, mic

Determine the glycogen receptors in the plasma membranes, Which of the foll...

Which of the following serves as an effector, or as part of an effector, that functions in a negative feedback system? A. Glycogen Receptors in the plasma membranes of liver ce

What do you mean by the coelom, Q. What is the coelom? To which structures ...

Q. What is the coelom? To which structures do coeloms give birth? Are all animals coelomate? Coeloms are cavities delimited by mesoderm and Coeloms originate the cavities where

Explain pound cake test - preformance evaluation, Pound cake test In so...

Pound cake test In some cases, oil or margarine creaming volume is most accuratelymeasured by preparing a regular pound cake, omitting the chemical leavener andmeasuring the vo

Haemocyanin - respiratory pigments, Haemocyanin - Respiratory Pigments ...

Haemocyanin - Respiratory Pigments This pigment is found in several arthropods and molluscs. Haemocyanins do not consist of haee groups. The metal they consist of is copper, w

Anatomy of coronary circulation, The epicardial coronary artery system cons...

The epicardial coronary artery system consists of the left and right coronary arteries, which normally arise from ostia located in the left and right sinuses of Valsalva, respectiv

Find the net charge of the predominant form asp, Determine the net charge o...

Determine the net charge of the predominant form Asp at (a) pH 1.0, (b) pH 3.0, (c) pH 6.0, and (d) pH 11.0?

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