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

Definition of epileptic seizures, Definition of Epileptic seizures Epil...

Definition of Epileptic seizures Epileptic seizures are classified as symptomatic seizures if they can be identified with a specific cause, such as infection, trauma, tumor, va

Controlling of gaseous pollutants, The gaseous pollutants can be controlled...

The gaseous pollutants can be controlled through the techniques of combustion, absorption adsorption and cold trapping. (a)   Combustion: Though combustion is a major cause of i

Determine the estimation of minerals in foods, Estimation of minerals in fo...

Estimation of minerals in foods The minerals in foods are determined by ashing or incineration at temperatures in the region of 500°C following standard procedure. This destroy

Explain gluten-free diet, Explain Gluten-free diet Gluten-free diet : ...

Explain Gluten-free diet Gluten-free diet : It is a diet recommended for the patients with gluten enteropathy. Gluten is present in wheat, rye, barley and oats. Thus, foods co

Spiracular control - respiration, Spiracular Control - Respiration ...

Spiracular Control - Respiration Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Determine the term - test-retest reliabilities, Determine the term - Test-r...

Determine the term - Test-retest reliabilities The test manual reports reliability data. Test-retest reliabilities for the 13 main scales range from .78 to .96. The problem of

Gonial apospory and somatic apospory, Gonial Apospory and Somatic Apospory ...

Gonial Apospory and Somatic Apospory Gonial Apospory There is no meiosis. The megaspore mother cell enlarges; a small vacuole appears above and below the nucleus. The c

Show foods that damage gi mucosa, Q. Show Foods that damage GI mucosa? ...

Q. Show Foods that damage GI mucosa? Foods that damage GI mucosa: A number of spices, herbs and other condiments have been found to have little or no irritating effect on the m

Amylase stock solution, Assume that you have 1 mL of a solution amylase (an...

Assume that you have 1 mL of a solution amylase (an enzyme) at a concentration of 15 mg protein/mL. Calculate the volume of diluting buffer that you would have to add to 1.0 mL of

Predict whether narrowing or widening of the blood vessels, Body temperatur...

Body temperature is homeostatic ally regulated around a set point. Given your knowledge of negative feedback and homeostatic control system, predict whether narrowing or widening o

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