Senescence, Biology


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.

Posted Date: 1/17/2013 7:51:34 AM | Location : United States

Related Discussions:- Senescence, Assignment Help, Ask Question on Senescence, Get Answer, Expert's Help, Senescence Discussions

Write discussion on Senescence
Your posts are moderated
Related Questions
Q. What are the hormones produced by the ovaries and the testicles? The testicles make androgenic hormones, the major of them being testosterone. The ovaries produce progestero

Viruses Viruses are sub cellular, ultramicroscopic infectious agents of 20 nm-300 nm size range Many of them cause diseases like polio, dengue, small pox, measles, rabies, com

How do leucine zipper binding motifs regulate gene expression?

Prevention of perinatal transmission  Zidovudine alone, started at 14-34 weeks of gestation and continued in the infant for the first 6 weeks of life, reduced HIV transmission

A student while studying the anatomy of leaves of four specimens (P - S), observed the following characters: P.  Reticulate venation and no bundle sheath. Q. Parallel venati

Excluding the effects of cardiac output and hormones, describe the other factors that may affect blood pressure and blood flow in a middle-aged man who is exercising in an aerobics

Segregation and Treatment of Dressing Waste In many departments waste is less and normally they do not have treatment facility for the bio-medical waste. In their case, interme

What is the location of the salivary glands in humans? There are 6 major salivary glands and they are located one in every parotid gland, two beneath the mandibles (submandibul

Determine the architecture of cell There are over 200 types of cells in the human body, which are assembled into a variety of tissues, such as, the epithelia, connective tissue

A d v a nce d vaccine technology: Genetic engineering technology is the major scientific revolution of 20th Century. This has helped in developing vaccine