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

What do you mean by trichomoniasis, Q. What is trichomoniasis? Why is it cl...

Q. What is trichomoniasis? Why is it classified as an STD? The Trichomoniasis is an extra-intestinal protozoan infection caused by the Trichomonas vaginalis, a flagellate proto

Phloem, why phloem made of living cells

why phloem made of living cells

Deficiency diseases-selenium and vitamin e deficiency, Selenium and vitamin...

Selenium and vitamin E deficiency Selenium is an essential micro-mineral required for various physiological functions and for immunity against a variety of diseases. It is an i

Define can we improve the nutritive value of protein, Define Can we improve...

Define Can we improve the nutritive value of protein? Yes, as discussed above, the nutritive value of a protein can be improved in two ways: (1) by mutual supplementation, that

Determine the causal factors of nervous system, Determine the Causal factor...

Determine the Causal factors of nervous system Although, the brain and spinal cord are surrounded by tough membranes, enclosed in the bones of the skull and spinal vertebrae, a

What proportion of children with down syndrome, What proportion of children...

What proportion of children with Down syndrome do you expect when women with Down syndrome have children with men who have 46 chromosomes justify your answer?

Regulation of pfk and fructose 1, When the level of AMP is high, this shows...

When the level of AMP is high, this shows the requirement for more ATP synthesis. AMP stimulates PFK increases the rate of glycolysis and inhibits fructose 1 and 6- bisphosphatase

Describe the general guidelines for use of bone grafting, General guideline...

General guidelines for use of BONE GRAFTING 1. The surgical site should be prepared, that is it should be free of granulation tissue. 2. For autogenous grafts- the donor sit

Define surface sampling, Define Surface Sampling Food contact surfaces ...

Define Surface Sampling Food contact surfaces (e.g. storage tank, packaging material, ripening room, utensils, equipments, refrigerators etc.) which directly or indirectly (wal

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