Senescence, Biology

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.

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
difference between the respiration occurs in lower and higher organisms

Psychological Problems Failure to fulfill the patient's expectations and failure to gain the patient's acceptance and satisfaction constitutes a psychological failure. It is hi

The excretion by the human kidneys 1. Descending limb of Loop of Henle is impermeable to water 2. Distal convoluted tubule is incapable of reabsorbing HCO3 3. Nearly 99 p

Determine Energy Requirements for Athletes? You are familiar with the fact that body needs' energy to maintain body temperature, to meet metabolic demands, maintain electrolyte

Q. What is Aflatoxin? Aflatoxins are the most widely studied of all mycotoxins. Knowledge of their existence dates from 1960, when more than 100,000 turkey died in England afte

Marine oils These oils typically contain large amounts of long - chain omega-3-polyunsaturated fatty acids, with up to six double bonds and they are usually rich in vitamins A

Q. What is the physiological cause of the syndrome Called as cretinism? Cretinism is caused by chronic deficiency of the thyroid hormones (T4and T3) during childhood. The chron

Describe how the International Astronomical Union defines a planet. Also include why Pluto is no longer considered a planet.

Meninges (Singular-Meninx) - Ceverings of brain. By infection in meninges meningitis or brain fever is caused. These menings are internally lined by squamous epitheliu

Polarity - Root and Shoot Morphogenesis Polarity is defined as having a difference (morphological, physiological or both) between the two ends of an axis or cells. This is lar